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JOHN P. TUOHY ET AL. v. TOWN OF GROTON ET AL.
                  (SC 20019)
             Robinson, C. J., and Palmer, McDonald, D’Auria,
                     Mullins, Kahn and Ecker, Js.*

                                   Syllabus

The plaintiffs, owners of certain properties located in a particular residential
   neighborhood in the town of Groton, appealed to the trial court pursuant
   to statute (§ 12-119), seeking a reduction in the assessments to their
   properties resulting from a townwide revaluation conducted by the
   defendants, the town and its assessor. The plaintiffs’ properties are
   each located in a planned community with exclusive access to certain
   amenities including a beach and a restaurant. The town hired T Co.,
   a certified mass appraisal vendor, to assist with the revaluation. In
   connection with the revaluation, T Co.’s employees went to each prop-
   erty to gather information. T Co. also sought to confirm the physical
   characteristics of each property through individualized mailings. Once
   the information collected was entered into a database used to generate
   property values, T Co. produced a preliminary property record and
   sent its employees to each property again to ensure accuracy. T Co.
   subsequently conducted a preliminary ratio test, which involved compar-
   ing the median sale price resulting from certain arm’s-length transactions
   and the median total value for the properties in the plaintiffs’ neighbor-
   hood, which already reflected an adjustment factor that had been applied
   in the preceding revaluation. T Co. determined that the resulting median
   assessment to sales ratio for the plaintiffs’ neighborhood fell outside of
   the acceptable range, and, consequently, T Co. and the town concluded
   that an increase in the adjustment factor was appropriate and necessary
   to bring the assessed values of the properties in the plaintiffs’ neighbor-
   hood closer to fair market values. In challenging the defendants’ assess-
   ments, the plaintiffs claimed, inter alia, that the defendants’ uniform
   application of the adjustment factor to increase the assessed values of
   all of the properties in their neighborhood without further individualized
   consideration of each property violated § 12-119. The trial court con-
   cluded that the defendants’ uniform application of the adjustment factor
   to the properties in the plaintiffs’ neighborhood did not violate § 12-
   199, rejected the plaintiffs’ argument that the defendants had disregarded
   a legal duty by applying ratio testing standards to specific neighbor-
   hoods, and credited testimony from both the assessor and T Co.’s project
   supervisor that the purpose of the higher adjustment factor was to adjust
   the assessments in order to bring them closer to fair market values.
   The trial court accordingly rendered judgment in favor of the defendants,
   from which the plaintiffs appealed. Held that the plaintiffs could not
   prevail on their claim that they were entitled to tax relief under § 12-
   119, this court having concluded that the defendants’ uniform application
   of the adjustment factor to the properties in the plaintiffs’ neighborhood
   was not illegal: although the plaintiffs’ correctly observed that townwide
   ratio testing is required by regulation (§ 12-62i-3) prior to finalizing a
   reevaluation, reading that regulation to preclude the use of ratio testing
   or the application of adjustment factors specific to particular neighbor-
   hoods during the mass appraisal process would require reading addi-
   tional language into its text, would be inconsistent with text in related
   regulations, and would conflict with another regulatory provision (§ 12-
   62f-4 [d]) that specifically contemplates such testing by neighborhood;
   moreover, the defendants’ use of a ratio study and direct equalization
   via an adjustment factor, as applied to a specific neighborhood, during
   the mass appraisal process was supported by appraisal standards set
   forth in various publications from professional associations, including
   the Appraisal Standards Board of the Appraisal Foundation and the
   International Association of Assessing Officers; furthermore, certain
   data presented at trial demonstrating a decrease in home sales prices
   in the plaintiffs’ neighborhood in the years preceding the revaluation
   were insufficient to establish illegality in the absence of evidence of the
   defendants’ misfeasance or malfeasance, and the plaintiffs failed to
   prove that the adjustment to the appraised value of their properties
   actually resulted in a manifest overvaluation of those properties relative
   to true and actual fair market values.
      Argued November 16, 2018—officially released May 28, 2019

                           Procedural History

  Appeal from tax assessments relating to certain resi-
dential property owned by the plaintiffs, brought to the
Superior Court in the judicial district of New London,
and transferred to the judicial district of New Britain,
where the court, Cohn, J., granted the plaintiffs’ motion
for class certification; thereafter, the case was trans-
ferred to the judicial district of Hartford and tried to
the court, Moll, J.; judgment for the defendants, from
which the plaintiffs appealed. Affirmed.
  Linda L. Morkan, with whom was John F.X. Peloso,
Jr., for the appellants (plaintiffs).
  Eileen Duggan, for the appellees (defendants).
                          Opinion

   ROBINSON, C. J. In this appeal, we consider whether
a municipality’s assessor may apply a uniform adjust-
ment factor to a neighborhood’s appraised property
values during the mass appraisal process for the revalu-
ation of real property pursuant to General Statutes § 12-
62 (b),1 as a direct equalization measure in order to
ensure that neighborhood is not undertaxed relative to
others in the municipality. The plaintiffs, John P. Tuohy
and numerous other owners of real property located
in the Groton Long Point neighborhood,2 brought this
class action tax appeal pursuant to General Statutes
§ 12-1193 against the defendants, the town of Groton
(town) and Mary Gardner, its assessor, challenging the
assessed value of their properties following the revalua-
tion conducted by the town for its October 1, 2011 grand
list (2011 revaluation). The plaintiffs now appeal4 from
the judgment in favor of the defendants, rendered after
a trial to the court, upholding the legality of those
assessments. On appeal, the plaintiffs claim that the
trial court incorrectly determined that their assess-
ments were not manifestly excessive because the defen-
dants violated § 12-62 and numerous provisions of the
Regulations of Connecticut State Agencies (regula-
tions) promulgated by the state Office of Policy and
Management (OPM); see Regs., Conn. State Agencies
§ 12-62i-1 et seq.; when they applied a flat, undifferenti-
ated adjustment factor that increased the assessed
value of all properties in Groton Long Point by 35 per-
cent without individualized consideration of the unique
characteristics of each property. We conclude that the
defendants properly applied an adjustment factor as
a direct equalization measure in connection with an
assessment to sales ratio study conducted pursuant to
various standards promulgated by the International
Association of Assessing Officers (international associ-
ation) in order to ensure that Groton Long Point bore
its fair share of the town’s municipal tax burden relative
to the town’s other neighborhoods. Accordingly, we
affirm the judgment of the trial court.
   The record reveals the following facts, as comprehen-
sively found by the trial court, Moll, J.,5 and procedural
history. ‘‘The plaintiffs are residential property owners
in the Groton Long Point . . . neighborhood6 of [the
town], who, on behalf of themselves and the certified
class,7 are challenging the [2011 revaluation]. [Groton
Long Point] is a planned community and comprises
approximately 600 properties. When someone owns
property in [Groton Long Point], he or she pays into
an association and has rights to use certain amenities
within the community, including the beach, docks,
piers, and association buildings, which include, among
other things, a restaurant. In addition, parking in [Gro-
ton Long Point] requires a permit.
  ‘‘The 2011 revaluation was a mass appraisal, defined
as ‘the process of valuing a universe of properties as
of a given date using standard methodology, employ-
ing common data, and allowing for statistical testing.
Methodology that is acceptable shall include, but is
not limited to, automated valuation models, adaptive
estimation procedure, multiple regression analysis, sta-
tistical analysis and other generally accepted tech-
niques . . . .’ Regs., Conn. State Agencies § 12-62i-1
(10). The 2011 revaluation was overseen by . . . Gard-
ner . . . whose position as the town assessor began in
June, 2011. Gardner first worked in the town’s assessor
office in 1986; she became a certified assessor in 1989.
The 2011 revaluation was the first revaluation that Gard-
ner conducted as an assessor.
   ‘‘To assist it with the 2011 revaluation, the town hired
Tyler Technologies (Tyler), a mass appraisal vendor
certified by the state to do revaluations. [See General
Statutes § 12-62 (e)]. The project supervisor from Tyler
with respect to the 2011 revaluation was Debra Christy
. . . who also is certified to do revaluations. Christy has
been employed with Tyler, although not continuously,
since 1980 and has been involved with revaluations in
the state of Connecticut since around 1997. Christy had
some responsibility in the 2006 revaluation of Groton
but was not the manager. In the 2011 revaluation,
Christy was responsible for the analysis for the residen-
tial property class.
   ‘‘The 2011 revaluation commenced in earnest in April,
2010, at which time Gardner was the assistant assessor
for the town. In April, 2010, the town issued a press
release informing the public that a revaluation would
be underway and that data collectors would be going
door to door to measure the exteriors of all properties
and to attempt interior inspection, if allowed. Tyler
conducted its data collection using data from the 2006
revaluation and updating it. Because the 2011 revalua-
tion was a full measure revaluation, Tyler [employees]
knocked on every door and did an exterior measure-
ment of every property. To the extent access to the
interior was not granted, Tyler sent the property owner
a callback letter to inquire whether the owner would
make a scheduled appointment for an interior inspec-
tion. Tyler then prepared and distributed data mailers
for each property; such data mailers reflected the prop-
erty’s physical characteristics that would be used in the
revaluation. Property owners were asked to contact
Tyler if any information required correction. Any
changes resulting from the data mailer process were
inputted into the Computer Assisted Mass Appraisal
(CAMA) software system, which the town uses for its
revaluations to generate property values. CAMA is certi-
fied by the state of Connecticut and is an example of
an ‘automated valuation model,’ as that phrase is used
in § 12-62i-1 (10) [of the regulations], which sets forth
the definition of ‘[m]ass appraisal.’ In CAMA, with
respect to each property, a value is assigned to the
land,8 and a value is assigned to any improvements or
structures using the cost approach (i.e., the cost of
replacement with an adjustment for depreciation). The
improvements value comprises a dwelling value and an
outbuilding value. One arrives at total value by adding
land value and improvements value.
  ‘‘Tyler then performed a prereview, which involved
producing all of the property record cards that were in
the system and having a certified field person go out
to each property to conduct what Tyler called a ‘wind-
shield prereview check’ to ensure that the information
on the cards was accurate.
  ‘‘After all data were collected and corrected during
the eighteen-month period following the initial press
release, Tyler engaged in preliminary ratio testing,
which required compiling a validated sales set (i.e.,
sales involving actual warranty deeds) using a two year
lookback period because of the number of sales.9 With
respect to [Groton Long Point], the sales set contained
eighteen validated, arm’s-length transactions. Tyler
compared the median of the sales identified for each
neighborhood against the median for the total value for
the neighborhood. A 1:1 ratio, meaning the medians
are equal, would be considered ideal. Tyler performed
preliminary ratio testing for each of the thirteen neigh-
borhoods within the town.10 The same process was fol-
lowed in 2006.
  ‘‘On October 31 and November 1, 2011, Christy con-
ducted four computer runs to create values for the
[Groton Long Point] residential properties using the
CAMA software. The 2006 revaluation had used an
adjustment factor of 1.2 (i.e., a 20 percent increase in
value) in setting the improvement values of the [Groton
Long Point] properties. Those adjustments were already
reflected in the CAMA database that Christy used in
conducting her analyses. Because an adjustment factor
of 1.2 was used in 2006 with respect to [Groton Long
Point] improvement values, Christy used that adjust-
ment factor as a starting point. Application of an adjust-
ment factor of 1.2 yielded a median assessment to sales
ratio (ASR)11 of 88.31 percent for [Groton Long Point].
Christy found this ratio to be outside an acceptable
range because it fell under 90 percent.12 In this regard,
Tyler and the town deemed [Groton Long Point] to
be an outlier. Specifically, in reaching this conclusion,
Christy relied on the [international association’s]13 prin-
ciple that, when looking at the level of assessment, if
market value is 100 percent, the [median] ASR should
be plus or minus 10 percent around market value.
Applying an adjustment factor of 1.4 yielded a median
ASR of 95.08 percent. Applying an adjustment factor of
1.4 with a waterfront adjustment yielded a median ASR
of 97.56 percent. Finally, application of an adjustment
factor of 1.35 yielded a median ASR of 92.03 percent.
  ‘‘Tyler and the town concluded that applying an
adjustment factor of 1.35 to the dwelling values within
[Groton Long Point] was appropriate and necessary to
reach fair market value. Christy reasoned that other
variables, including a coefficient of dispersion, fell
within a preferred range to reach uniformity. [Tyler did
not physically reinspect any of the Groton Long Point
properties prior to applying the 1.35 adjustment
factor.]14
  ‘‘Christy conducted sales ratio studies with respect
to each of the other twelve neighborhoods. Using a 1.0
factor, each neighborhood’s median ASR landed above
90 percent (and below 100 percent market value). For
each of the other neighborhoods, the resulting median
ASRs were as follows:
  1010—Center Groton 91.80 percent
  1020—City of Groton 92.99 percent
  1021—City of Groton—Eastern 96.43 percent
  1030—Poquonock Bridge 96.28 percent
  1040—Mystic 94.10 percent
  1041—Mystic Village 94.37 percent
  1050—Noank 95.08 percent
  1051—Noank Village 94.69 percent
  1060—Old Mystic 96.46 percent
  1061—Old Mystic—River Road 95.14 percent
  1080—West Pleasant Valley 95.73 percent
  1090—Mumford Cove 94.78 percent
  Because these median ASRs fell above 90 percent,
and therefore were deemed acceptable, no adjustments
were made.
   ‘‘Thereafter, Tyler entered into what it called the final
review phase. Because the town had elected to use ratio
testing standards, and not procedural testing standards,
Christy conducted ratio testing to residential property
townwide to assure satisfaction of the requirements of
§ 12-62i-3 (b) [of the regulations]. Such testing to such
property class on a townwide basis resulted in those
criteria being met on the first try. Therefore, no further
analysis was performed pursuant to § 12-62i-3 (c). The
town subsequently submitted to [OPM] the statutorily
required certification of compliance, which was signed
by Christy and Gardner and which reflected that the
town utilized ratio testing standards.’’15 (Footnotes
added and in original.)
   The plaintiffs subsequently brought this class action
pursuant to § 12-119, seeking reduction of the assess-
ments on the relevant properties in Groton Long Point.
The plaintiffs claimed, inter alia, that the ‘‘uniform appli-
cation of the 1.35 adjustment factor to residential build-
ings’’ violated § 12-119 because (1) ‘‘the application of
a fixed percentage factor to increase assessments with-
out making any allowance for individual differences in
properties has been widely condemned by the courts of
this state,’’ (2) ‘‘the basic deficiency of such a valuation
procedure is the failure to consider all of the elements
which may reasonably affect the value of the property,’’
(3) ‘‘the assumption that residential buildings in Groton
Long Point are worth 35 percent more than comparable
structures elsewhere in the town, including but not
limited to structures in the sections of town classified
as Mumford Cove, Mystic Village, and Noank Village,
is arbitrary, unreasonable, and without foundation in
fact,’’ and (4) ‘‘the application of the fixed percentage
factor by the assessor to increase the assessments on
properties in Groton Long Point cannot reasonably be
found to fulfill her statutory duty to determine the true
and actual valuation of each individual property, in vio-
lation of [General Statutes] § 12-64 . . . .’’
   Following certification of the class; see footnote 7 of
this opinion; the case was tried to the court.16 After
conducting a comprehensive review of the governing
statutory and regulatory framework, and particularly
the ratio testing standard set forth in § 12-62i-3 of the
regulations17 for evaluating the performance of the
revaluation process, the trial court concluded that the
‘‘1.35 adjustment factor applied to the [Groton Long
Point] dwelling values did not violate § 12-119.’’ In so
concluding, the trial court rejected the plaintiffs’ argu-
ment that the defendants had disregarded a legal duty
insofar as the ratio testing standards may be applied
only on a townwide basis, rather than to specific neigh-
borhoods on a preliminary basis. The trial court also
rejected the plaintiffs’ reliance on Chamber of Com-
merce of Greater Waterbury, Inc. v. Waterbury, 184
Conn. 333, 439 A.2d 1047 (1981), for the ‘‘proposition
that, in the revaluation context, the application of a
fixed percentage without allowance for individual prop-
erty differences is illegal pursuant to § 12-119’’; the court
distinguished that case factually with respect to the
extensive, individualized data collection that took place
in the present case. To this end, the trial court con-
cluded that Tyler was not required to ‘‘physically
[re]inspect the [Groton Long Point] residential proper-
ties’’ after it discovered that the initial ‘‘application of
the original 1.2 adjustment factor yielded a median ASR
of 88.31 percent . . . .’’18 Having credited the testimony
of Gardner and Christy to the effect that the 1.35 adjust-
ment factor ‘‘was used for the express purpose of
increasing the [Groton Long Point] appraised values so
that they would be closer to fair market value, instead
of well below fair market value,’’ the trial court rejected
the plaintiffs’ claim that ‘‘their assessments were mani-
festly excessive’’ and the ‘‘illegal’’ result of ‘‘disregard
of the relevant statutes . . . .’’ Accordingly, the trial
court rendered judgment for the defendants. This
appeal followed.
   On appeal, the plaintiffs claim that the trial court
incorrectly concluded that the defendants’ assessment
of Groton Long Point in the 2011 revaluation was not
illegal. The plaintiffs renew their reliance on Chamber
of Commerce of Greater Waterbury, Inc., and contend
that the defendants’ use of an undifferentiated adjust-
ment factor of 1.35 disregarded the ‘‘individualized
process’’ required by § 12-62, insofar as ‘‘[t]here is no
provision in our state statutes or the pertinent regula-
tions that allows an assessor to apply a flat percentage
to a group of properties simultaneously in order to
‘adjust’ their true and actual value.’’ The plaintiffs fur-
ther argue that the defendants’ use of the adjustment
factor was not authorized by § 12-62i-3 of the regula-
tions, which contemplates the use of ratio testing for
property classes, namely, residential, commercial, and
vacant land, rather than ‘‘on much smaller groups, i.e.,
residential neighborhoods,’’ and only to verify results,
not ‘‘to actually set the assessed values themselves.’’
The plaintiffs contend that any discrepancy resulting
from the initial mass appraisal should have been
addressed by ‘‘physically revisit[ing] those properties
[to] verify the data collection and the information it
produced,’’ rather than arbitrarily ‘‘running calculations
until the numbers (subjectively) seem to more closely
approximate some ideal of fair market value in the
assessor’s mind . . . .’’19 Finally, the plaintiffs rely on
Hartford/Windsor Healthcare Properties, LLC v. Hart-
ford, 298 Conn. 191, 3 A.3d 56 (2010), and argue that
the trial court improperly found that they had ‘‘failed
to demonstrate that the 2011 [revaluation] resulted in
assessments that are manifestly excessive,’’ because
that determination is ‘‘part and parcel of the stipulation
that the defendants uniformly inflated the assessed
value of the subject properties by 35 percent even
though such an adjustment was not required in order
to comply with the statutory standards.’’
   In response, the defendants contend that they prop-
erly utilized the 1.35 adjustment factor to compensate
for patterns of undervaluation of Groton Long Point
properties relative to other neighborhoods in the town.
The defendants argue that this methodology was consis-
tent with the OPM regulations and the standards of
the international association, and emphasize that OPM
itself ultimately certified the results of the appraisal.
Thus, the defendants also rely on Redding Life Care,
LLC v. Redding, 308 Conn. 87, 61 A.3d 461 (2013), and
contend that the plaintiffs have failed to prove a viola-
tion of § 12-119 because their complaint of ‘‘inadequate
substantiation to support application of the 1.35 adjust-
ment factor’’ pertains to insufficiency of data and a
challenge to the appraisal methodology, rather than
demonstrating illegality. The defendants further argue
that Chamber of Commerce of Greater Waterbury, Inc.
v. Waterbury, supra, 184 Conn. 333, is distinguishable
from the present case because, in addition to engaging
in a comprehensive preappraisal field data gathering as
to every property in town, Tyler reanalyzed that field
data subsequent to the adjustment to verify the consis-
tency of the mass appraisal results with actual property
values as determined by sales. Finally, the defendants
contend that the plaintiffs failed to prove that the valua-
tion of their properties was manifestly excessive
because they did not present any credible evidence
of the values of their properties. We agree with the
defendants and conclude that their application of the
1.35 adjustment factor to the Groton Long Point residen-
tial properties during the 2011 revaluation was not
illegal.
   ‘‘In a tax appeal taken pursuant to § 12-119, the plain-
tiff must prove that the assessment was (a) manifestly
excessive and (b) . . . could not have been arrived at
except by disregarding the provisions of the statutes
for determining the valuation of the property. . . .
[The plaintiff] must [set forth] allegations beyond the
mere claim that the assessor overvalued the property.
[The] plaintiff . . . must satisfy the trier that [a] far
more exacting test has been met: either there was mis-
feasance or nonfeasance by the taxing authorities, or
the assessment was arbitrary or so excessive or discrim-
inatory as in itself to show a disregard of duty on their
part. . . . Only if the plaintiff is able to meet this exact-
ing test by establishing that the action of the assessors
would result in illegality can the plaintiff prevail in an
action under § 12-119. The focus of § 12-119 is whether
the assessment is illegal. . . . The statute applies only
to an assessment that establishes a disregard of duty
by the assessors. . . .
   ‘‘While an insufficiency of data or the selection of an
inappropriate method of appraisal could serve as the
basis for not crediting the appraisal report that resulted,
it could not, absent evidence of misfeasance or malfea-
sance, serve as the basis for an application for relief
from a wrongful assessment under § 12-119. . . . In
short, when reviewing a claim raised under § 12-119, a
court must determine whether the plaintiff has proven
that the assessment was the result of illegal conduct.’’20
(Emphasis in original; internal quotation marks omit-
ted.) Walgreen Eastern Co. v. West Hartford, 329 Conn.
484, 513–14, 187 A.3d 388 (2018). Put differently, tax
relief under § 12-119 is available only in an ‘‘extraordi-
nary situation.’’ Second Stone Ridge Cooperative Corp.
v. Bridgeport, 220 Conn. 335, 343, 597 A.2d 326 (1991).
    Whether an assessment methodology violates the
governing statutes and regulations for purposes of § 12-
119 presents a question of law over which our review
is plenary. See, e.g., Griswold Airport, Inc. v. Madison,
289 Conn. 723, 739, 961 A.2d 338 (2008); see also Red-
ding Life Care, LLC v. Redding, supra, 308 Conn. 101
(‘‘[w]hen a tax appeal . . . raises a claim that chal-
lenges the propriety of a particular appraisal method
in light of a generally applicable rule of law, our review
of the trial court’s determination whether to apply the
rule is plenary’’ [internal quotation marks omitted]);
Griswold Airport, Inc. v. Madison, supra, 741–42
(applying plenary review to claim that assessor violated
General Statutes § 12-504h by terminating property’s
open space classification and assessing it as condomin-
ium units).
    Our review of the legality of the assessment begins
with the OPM regulations, which were promulgated
pursuant to § 12-62 (g); see footnote 17 of this opinion;
for the purpose of guiding the revaluation process under
§ 12-62 (b) (2), which contemplates both a ‘‘field
review’’ of the properties and the use of ‘‘generally
accepted mass appraisal methods which may include,
but need not be limited to, the market sales comparison
approach to value, the cost approach to value and the
income approach to value.’’ Beyond the regulations, we
also consider the extent to which the appraisal com-
plied with the Uniform Standards of Professional
Appraisal Practice, as promulgated by the Appraisal
Standards Board of the Appraisal Foundation, which
‘‘[r]eal estate appraisers in Connecticut are required to
follow’’ pursuant to General Statutes § 20-504. Redding
Life Care, LLC v. Redding, supra, 308 Conn. 107 n.18.
   Section 12-62 (g) (2) mandates the promulgation of
regulations ‘‘establishing criteria for measuring the level
and uniformity of assessments generated from a revalu-
ation,’’ and provides that ‘‘such criteria shall be applica-
ble to different classes of real property with respect to
which a sufficient number of property sales exist.’’ The
regulations promulgated by OPM in response to that
mandate, in turn, provide that ‘‘[p]erformance-based
revaluation standards shall consist of two acceptable
methods as set forth in section[s] 12-62i-3 and 12-62i-4
of the [r]egulations . . . .’’ Regs., Conn. State Agencies
§ 12-62i-2. Ratio testing, one of the two acceptable meth-
ods, is governed by § 12-62i-3 of the regulations. That
regulation requires an assessor conducting ratio testing
to establish ‘‘[a] file of all real property sales transac-
tions for the sales time period used’’; Id., § 12-62i-3 (a)
(1); and also provides that, ‘‘[p]rior to finalizing a revalu-
ation, the assessor shall conduct the following tests
regarding the assessments derived from such revalua-
tion. The assessments resulting from the revaluation
shall be deemed sufficient, provided the following crite-
ria are met:
  ‘‘(1) the overall level of assessment for all property
classes shall be within plus or minus ten percent of the
required seventy percent assessment ratio, as measured
by the overall median ratio, and
  ‘‘(2) the level of assessment for each property class
with fifteen or more market sales shall be within plus
or minus five percent of the median overall level of
assessment for each property class, and
  ‘‘(3) the coefficient of dispersion for each property
class with fifteen or more market sales shall be equal
to or less than fifteen percent for all property, equal to
or less than fifteen percent for residential property,
equal to or less than twenty percent for commercial
property, and equal to or less than twenty percent for
vacant land, and
  ‘‘(4) the price related differential for all properties
and for each property class for which there are fifteen
or more market sales shall be within 0.98 and 1.03, and
   ‘‘(5) the unsold property test result shall be between
0.95 and 1.05.’’ Id., § 12-62i-3 (b).
   The ratio testing regulation further provides that, if
its criteria ‘‘are not met, the assessor shall, prior to the
implementation of the revaluation, further analyze and
refine the data elements or methods used in the reval-
uation. The assessor shall revalue the parcels of real
property for which a deficiency in either the level of
assessment or the uniformity of assessments has been
identified.’’ Id., § 12-62i-3 (c).
   The plaintiffs correctly read the ratio testing regula-
tion as mandating such evaluation following the com-
pletion of the appraisal by general ‘‘ ‘[p]roperty class,’ ’’
which is defined as ‘‘any one of the following three
major classifications of real property: (A) residential;
(B) commercial including apartments, industrial and
public utility; and (C) vacant land . . . .’’ Id., § 12-62i-
1 (15). There are, however, two problems with the plain-
tiffs’ interpretation of the ratio testing regulation. First,
that regulation does not expressly preclude the use of
ratio testing or adjustment factors during the mass
appraisal process by ‘‘ ‘[n]eighborhood,’ ’’ which is
defined as ‘‘a geographic area of complementary real
property parcels that share similar locational and mar-
ket value characteristics, and may be defined by natural,
man-made, or political boundaries . . . .’’ Id., § 12-62i-
1 (13). Reading the ratio testing regulation in the manner
urged by the plaintiffs would require us to add nonexis-
tent language to its text, which is not how we read
regulations. See, e.g., Williams v. General Nutrition
Centers, Inc., 326 Conn. 651, 657, 166 A.3d 625 (2017)
(‘‘because regulations have the same force and effect
as statutes, we interpret both using the plain meaning
rule’’); Mayer v. Historic District Commission, 325
Conn. 765, 776, 160 A.3d 333 (2017) (‘‘it is well settled
that [w]e are not permitted to supply statutory language
that the legislature may have chosen to omit’’ [internal
quotation marks omitted]).
  Second, the plaintiffs’ reading of § 12-62i-3 of the
regulations is inconsistent with the other regulatory
text, which defines ‘‘ ‘[r]evaluation’ ’’ as ‘‘the mass
appraisal of property to determine the true and actual
value of all real property in a town for assessment
purposes in accordance with section 12-62 . . . .’’
Regs., Conn. State Agencies § 12-62i-1 (19). The very
meaning of ‘‘ ‘[m]ass appraisal’ ’’ contemplates some
estimation, insofar as it is defined as ‘‘the process of
valuing a universe of properties as of a given date using
standard methodology, employing common data, and
allowing for statistical testing. Methodology that is
acceptable shall include, but is not limited to, auto-
mated valuation models, adaptive estimation proce-
dure, multiple regression analysis, statistical analysis
and other generally accepted techniques . . . .’’ Id.,
§ 12-62i-1 (10). Indeed, § 12-62f-4 of the regulations,
which governs the valuation module to be used for
computer assisted mass appraisal, specifically antici-
pates such testing on a neighborhood basis, as such a
valuation module must have ‘‘the capacity to calculate,
print reports and output to standard analytical software
programs the following measurements and sales/assess-
ment ratios by property type and neighborhood: Sales
prices; assessments; the mean sales/assessment ratio;
the median sales/assessment ratio; the coefficient of
dispersion; the standard deviation; the coefficient of
variation; and the price-related differential.’’ (Emphasis
added.) Id., § 12-62f-4 (d). Thus, to read § 12-62i-3 of
the regulations in a manner absolutely precluding ratio
testing on a more granular level than property class
during the mass appraisal process would make little
sense, as that regulation simply furnishes a broad mea-
sure of quality control to be implemented ‘‘[p]rior to
finalizing a revaluation . . . .’’ Id., § 12-62i-3 (b).
   Beyond the lack of regulatory or statutory preclusion,
the Uniform Standards of Professional Appraisal Prac-
tice support the defendants’ use of a ratio study during
the mass appraisal process at issue in the present case.21
Specifically, rule 6-7 of the Uniform Standards of Profes-
sional Appraisal Practice provides that ‘‘[i]n reconciling
a mass appraisal an appraiser must: (a) reconcile the
quality and quantity of data available and analyzed
within the approaches used and the applicability and
relevance of the approaches, methods and techniques
used; and (b) employ recognized mass appraisal testing
procedures and techniques to ensure that standards of
accuracy are maintained.’’ Appraisal Standards Board,
Appraisal Foundation, 2010-11 Uniform Standards of
Professional Appraisal Practice (2010) p. U-51. The
commentary to that rule observes that ‘‘[i]t is implicit
in mass appraisal that, even when properly specified
and calibrated mass appraisal models are used, some
individual value conclusions will not meet standards of
reasonableness, consistency, and accuracy. However,
appraisers engaged in mass appraisal have a profes-
sional responsibility to ensure that, on an overall basis,
models produce value conclusions that meet attainable
standards of accuracy. This responsibility requires
appraisers to evaluate the performance of models,
using techniques that may include but are not limited
to, goodness-of-fit statistics, and model performance
statistics such as appraisal-to-sale ratio studies, eval-
uation of hold-out samples, or analysis of residuals.’’
(Emphasis added.) Id.; see also id., p. U-53 (noting that
written report of mass appraisal must ‘‘describe calibra-
tion methods considered and chosen,’’ ‘‘identify the
appraisal performance tests used and set forth the per-
formance measures attained,’’ and ‘‘describe the recon-
ciliation performed [under rule] 6-7’’).
   Consistent with the Uniform Standards of Profes-
sional Appraisal Practice, the use of ratio studies and
‘‘direct equalization’’ via the application of adjustment
factors are an established component of mass appraisal
practice, and are specifically embraced by the interna-
tional association. See generally International Associa-
tion of Assessing Officers, Standard on Ratio Studies
(2013); International Association of Assessing Officers,
Fundamentals of Mass Appraisal (2011).22 The ‘‘assess-
ment standards set forth’’ in the international associa-
tion’s standards ‘‘represent a consensus in the assessing
profession,’’ and the international association’s execu-
tive board adopted them in order to ‘‘provide a sys-
tematic means by which concerned assessing officers
can improve and standardize the operation of their
offices.’’ Standard on Ratio Studies, supra, p. 1. Those
standards have been considered authoritative in this
area by sister state high courts. See Douglas v. Nebraska
Tax Equalization & Review Commission, 296 Neb.
501, 508, 894 N.W.2d 308 (2017) (‘‘[g]enerally accepted
mass appraisal techniques include the standards prom-
ulgated by the [international association]’’); Clifton v.
Allegheny, 600 Pa. 662, 694, 969 A.2d 1197 (2009) (noting
that international association standards ‘‘are widely
accepted as the best criteria for judging the adequacy
of a property assessment’’); see also Thorsness v. Porter
County Assessor, 3 N.E.3d 49, 53 (Ind. Tax 2014) (not-
ing that state ‘‘administrative agency charged with
ensuring that . . . property assessments are uniform
and equal—has provided guidance about how to com-
pile and evaluate the data necessary for an assessment
ratio study’’ by adopting international association’s
standards ‘‘through its duly promulgated administrative
regulations’’ [footnote omitted]). A separate publication
by the international association, entitled Fundamentals
of Mass Appraisal, complements their standards and
serves as a more general ‘‘textbook [that] is intended
to provide a basic understanding and overview of the
many factors that shape mass appraisal theory and prac-
tice.’’ Fundamentals of Mass Appraisal, supra, p. v.
   Beyond their use in quality control by oversight agen-
cies such as OPM, the international association’s stan-
dards suggest specifically that ratio studies may be
utilized internally to ‘‘help improve appraisal methods
or identify areas within the jurisdiction that need atten-
tion.’’ Standard on Ratio Studies, supra, p. 7. Ratio stud-
ies may be used to consider the accuracy of a mass
appraisal, including with respect to ‘‘[u]niformity’’ or
‘‘the degree to which properties are appraised at equal
percentages of market value.’’23 Id.; see also id., p. 8
(‘‘Local jurisdictions should use ratio studies as a pri-
mary mass appraisal testing procedure and their most
important performance analysis tool. The ratio study
can assist such jurisdictions in providing fair and equita-
ble assessment of all property.’’). The ‘‘ratio study is a
form of applied statistics, because the analyst draws
conclusions about the appraisal of the population (the
entire jurisdiction) of properties based only on those
that have sold during a given time period. The sales
ratios constitute the sample that will be used to draw
conclusions or inferences about the population.’’ Id.,
p. 8.
   With respect to data collection and analysis, the inter-
national association’s standards contemplate ‘‘[s]tratifi-
cation [to divide] all the properties within the scope of
the study into two or more groups or strata,’’ which
‘‘facilitates a more complete and detailed picture of
appraisal performance and can enhance sample repre-
sentativeness.’’ Id., p. 9. In observing that stratification
can ‘‘help identify differences in level of appraisal
between property groups,’’ those standards specifically
suggest that ‘‘neighborhood’’ is an appropriate stratum,
in addition to ‘‘[e]ach type of property subject to a
distinct level of assessment,’’ with ‘‘stratification by geo-
graphic areas . . . generally more appropriate for resi-
dential properties . . . .’’ Id. Once appropriate sales
are identified during the collection of market data, the
statistical analysis takes place, as those sales are
‘‘matched against assessed values, ratios computed, and
outliers identified and removed if appropriate, mea-
sures of appraisal level, uniformity, and reliability for
the entire jurisdiction and each group or stratum should
be computed.’’ Id.
   The international association allows for a 10 percent
‘‘window . . . about the market value standard [as] a
reasonable range in which measures of central tendency
should fall in ad valorem mass appraisal.’’ Fundamen-
tals of Mass Appraisal, supra, p. 243. This ‘‘standard
provides a reasonable, constructive, and cost-effective
basis for ensuring that appraisals approximate market
values.’’ Id. With respect to uniformity among the vari-
ous strata, ‘‘[e]ach major stratum should be appraised
within 5 percent of the overall level of appraisal for the
jurisdiction. Thus, if the overall level is 0.900, each
property class and area should be appraised between
0.855 and 0.945 . . . .’’ Id.; see also Standard on Ratio
Studies, supra, pp. 18–19.
   Most significantly, the international association’s
standards contemplate the ‘‘common’’ use of ‘‘[e]qual-
ization . . . to address problems associated with
appraisal level,’’ while also observing that ‘‘[r]eappraisal
orders can be used to correct uniformity problems.’’
Standard on Ratio Studies, supra, p. 21. ‘‘Equalization,’’
in general, is the ‘‘process by which an appropriate
governmental body attempts to ensure that property
under its jurisdiction is assessed at the same assessment
ratio or at the ratio or ratios required by law. Equaliza-
tion can be undertaken at many different levels. Equal-
ization among use classes (such as agricultural and
industrial property) can be undertaken at the local level
. . . .’’ Id., p. 40. ‘‘Direct equalization’’24 is the ‘‘process
of converting ratio study results into adjustment factors
(trends) and changing locally determined appraised or
assessed values to more nearly reflect market value or
the legally required level of assessment.’’25 Id.
    Although the international association’s standards
caution that ‘‘[e]qualization is not an appraisal or a
substitute for reappraisal,’’ they nevertheless counsel
that the advantage of direct equalization is that it ‘‘can
be applied to specified strata, such as property classes,
geographic areas, and political subdivisions that fail
to meet appraisal level performance standards . . . .
Direct equalization also produces results that are gener-
ally more visible to the taxpayer and more clearly
reduces perceived inequities between classes . . . .’’
(Citations omitted; emphasis added.) Id., p. 21; see also
id., p. 23 (‘‘[o]ther property groups, such as market
areas, school districts and tax units, could constitute
additional strata’’). Indeed, when ‘‘applied at the stra-
tum level [direct equalization] improves equality in
effective tax rates between strata and lessens the effect
of assessment practices that improperly favor one stra-
tum over another.’’26 Id., p. 22. Those standards note that
‘‘[s]tratification can help identify differences in level of
appraisal between property groups. In large jurisdic-
tions, stratification by market areas is generally more
appropriate for residential properties, while stratifica-
tion of commercial properties by either geographic area
or property subtypes (e.g., office, retail, and warehouse/
industrial) can be more effective.’’ Id., p. 24. Such
‘‘[s]tratification facilitates a more complete and detailed
picture of appraisal performance and can enhance sam-
ple representativeness.’’ Id., p. 23.
   ‘‘If noncompliance with either direct or indirect equal-
ization standards is indicated, the appropriate point
estimate (statistic) measuring appraisal level should be
used to calculate adjustment factors, by dividing it into
100 percent.’’ Id., p. 35. Accordingly, we conclude that
the record demonstrates that the use of ratio studies
and direct equalization via adjustment factors as applied
to a neighborhood stratum is a valid component of mass
appraisal practice under the standards adopted by the
international association.
   Having determined that the defendants validly incor-
porated ratio studies and direct equalization via adjust-
ment factors to neighborhood strata into the 2011
revaluation, we further conclude that the trial court
properly rejected the plaintiffs’ challenge to their use
in this specific case. The trial court credited Gardner’s
testimony that the application of the 1.35 percent adjust-
ment factor to the dwellings in Groton Long Point was
necessary to bring the median ASR for that neighbor-
hood in line with the other neighborhoods in the town,
and to keep the properties in Groton Long Point from
being undervalued—and therefore undertaxed—rela-
tive to the rest of the town. Gardner testified that strati-
fication by neighborhood was necessary because
Groton has thirteen neighborhoods, each ‘‘unique to
itself,’’ with five on the water and others with ‘‘interior
cookie cutter homes.’’ Although the amenities available
to Groton Long Point residents, such as the private
beaches and dock, run with the land, Gardner elected
to adjust the building values as a component of the
total value, rather than the land values, because she
had high confidence in the underlying land values based
on a comparison to three valid vacant lot sales. ‘‘[T]his
court has held that [t]he process of estimating the value
of property for taxation is, at best, one of approximation
and judgment, and there is a margin for a difference of
opinion. . . . There may be more ways than one for
estimating the value of such . . . [property] for taxa-
tion. . . . Many factors may enter into the determina-
tion of the value of a piece of property. Its value is, in the
final analysis, a matter of opinion.’’ (Citation omitted;
internal quotation marks omitted.) Redding Life Care,
LLC v. Redding, supra, 308 Conn. 110.
   This court’s decision in Chamber of Commerce of
Greater Waterbury, Inc. v. Waterbury, supra, 184 Conn.
333, on which the plaintiffs rely heavily, is distinguish-
able and does not invalidate the town’s 2011 revaluation
as a matter of law. In that case, we considered a chal-
lenge to Waterbury’s revised grand list for October 1,
1979, which ‘‘consisted of adjustments made in the
assessments of about 300 commercial and industrial
properties, which [the assessor] and his staff inspected
and analyzed individually, and a 28 percent increase
‘across the board’ in the assessments of the remaining
commercial and industrial properties in Waterbury,
approximately 2500 in number.’’ Id., 334–35. This court
affirmed the judgment of the trial court enjoining the
fixed 28 percent increase, determining that the ‘‘applica-
tion of a fixed percentage factor to increase assess-
ments without making any allowance for individual
differences in properties has been widely condemned.
. . . The basic deficiency of such a valuation procedure
is the failure to consider all of the elements which may
reasonably affect the value of the property.’’ (Citations
omitted.) Id., 336–37.
   In concluding that the fixed 28 percent increase with-
out consideration of the properties’ individual charac-
teristics was illegal, this court observed that, under
§§ 12-64 (a) and 12-62 (a), ‘‘[t]axable property is subject
to taxation at a uniform percentage of ‘its present true
and actual valuation.’ . . . In establishing assessments
the assessors are required to ‘view all of the real estate
of their respective municipalities.’ . . . These statutes
contemplate assessments based upon a considera-
tion of the individual characteristics of each property
listed.’’ (Citations omitted.) Id., 337. The court con-
cluded that the ‘‘28 percent increase in the valuations
of the 2500 commercial and industrial properties which
[the assessor] did not examine individually was a pro-
jection from the conclusion he reached from his analy-
sis of 300 such properties upon an individual basis.
His conclusion of a minimum 28 percent underval-
uation of those properties could not fairly be applied
to all other business properties in Waterbury without
some showing that the undervaluation had occurred
for reasons affecting all business properties alike. We
cannot assume that the 300 properties studied by the
assessor are sufficiently similar in character or loca-
tion to allow a reasonable inference that the remaining
2500 properties have been uniformly undervalued by
28 percent.’’27 (Emphasis added.) Id., 337. Accordingly,
the court concluded ‘‘that the application of the fixed
percentage factor by the assessor to increase the assess-
ments on the properties of the plaintiffs cannot reason-
ably be found to fulfill his statutory duty to determine
the ‘true and actual valuation’ of each individual prop-
erty.’’28 Id., 338.
   Chamber of Commerce of Greater Waterbury, Inc.,
is readily distinguishable from the present case. First,
the record in the present case reveals that Gardner and
the assessment team from Tyler made an individual
assessment of every property in the town—including
field visits, requests for inspections, and communica-
tions with each homeowner prior to the finalization of
the assessment in accordance with § 12-62 (b) and § 12-
62i-3 of the regulations. The trial court reasonably cred-
ited the testimony of Gardner and Christy that addi-
tional visits were not necessary prior to the application
of the adjustment because they had gained all relevant
information about the properties. See footnote 14 of
this opinion and accompanying text. Second, in contrast
to Chamber of Commerce of Greater Waterbury, Inc.,
the adjustment in this case was not applied townwide,
but rather, only to a narrow strata of properties in a
unique neighborhood in connection with a computer
assisted mass appraisal that was conducted in accor-
dance with both the OPM regulations and widely
accepted appraisal standards. Accordingly, we con-
clude that Chamber of Commerce of Greater Water-
bury, Inc., does not render the assessment in the
present case illegal.29
   The plaintiffs contend, however, that the application
of the 1.35 adjustment factor was invalid because it was
arbitrarily chosen by Christy, ‘‘had no mathematical or
technical connection to the initial assessments made
by the CAMA program, and was not intended to remedy
some specific defect.’’ They argue that it is ‘‘completely
unrelated to the true and actual value of each home in
Groton Long Point.’’ To this end, the plaintiffs rely on
certain data presented through the testimony of Edward
Bogdan, a member of the certified class in the present
case; see footnote 7 of this opinion; in support of the
proposition that Groton Long Point experienced a 25
percent decrease in home sale prices between 2009 and
2011. Specifically, the plaintiffs posit that this informa-
tion undermines the sales set utilized by Christy in
performing her assessments. This evidence is insuffi-
cient, however, to establish illegality, insofar as ‘‘[w]hile
an insufficiency of data or the selection of an inappro-
priate method of appraisal could serve as the basis for
not crediting the appraisal report that resulted, it could
not, absent evidence of misfeasance or malfeasance,
serve as the basis for an application for relief from
a wrongful assessment under § 12-119.’’ Second Stone
Ridge Cooperative Corp. v. Bridgeport, supra, 220
Conn. 343; see also Redding Life Care, LLC v. Redding,
supra, 308 Conn. 111 (‘‘although the plaintiff may dis-
agree that the hypothetical condition was necessary to
reach the valuation, it has failed to demonstrate that
the town assessor’s reliance on the condition was ille-
gal, and, accordingly, the plaintiff cannot prevail on its
claim under § 12-119’’ [emphasis in original]). Moreover,
the plaintiffs have failed to introduce evidence to prove
that the adjustment to the appraised value—even by 35
percent—actually resulted in a manifest overvaluation
of their properties relative to true and actual fair market
value.30 See Walgreen Eastern Co. v. West Hartford,
supra, 329 Conn. 513 (‘‘[m]ere overvaluation, without
more, in an assessment of property is not enough to
make out a case under § 12-119’’ [internal quotation
marks omitted]); see also id., 513–14 ($120,000 valuation
error on approximately $5 million property, which was
2.4 percent, was not manifestly excessive for purposes
of relief under § 12-119); cf. Griswold Airport, Inc. v.
Madison, supra, 289 Conn. 741–42 (because improper
removal of airport’s open space classification in viola-
tion of § 12-504h ‘‘caused its assessed value to grow
more than eightfold,’’ this court concluded that ‘‘the
trial court’s determination . . . necessarily incorpo-
rated an implicit finding that the resultant assessment
was manifestly excessive’’). Accordingly, ‘‘we conclude
that the circumstances presented here do not rise to
the level of the extraordinary situation that would war-
rant tax relief under the provisions of § 12-119.’’ (Inter-
nal quotation marks omitted.) Walgreen Eastern Co. v.
West Hartford, supra, 514.
   The judgment is affirmed.
   In this opinion the other justices concurred.
  * This case originally was scheduled to be argued before a panel of this
court consisting of Chief Justice Robinson and Justices Palmer, McDonald,
D’Auria, Mullins, Kahn and Ecker. Although Chief Justice Robinson was not
present when the case was argued before the court, he has read the briefs
and appendices, and listened to a recording of the oral argument prior to
participating in this decision.
  1
    General Statutes § 12-62 (b) provides: ‘‘(1) Commencing October 1, 2006,
each town shall implement a revaluation not later than the first day of
October that follows, by five years, the October first assessment date on
which the town’s previous revaluation became effective, provided, a town
that opted to defer a revaluation, pursuant to section 12-62l, shall implement
a revaluation not later than the first day of October that follows, by five years,
the October first assessment date on which the town’s deferred revaluation
became effective. The town shall use assessments derived from each such
revaluation for the purpose of levying property taxes for the assessment
year in which such revaluation is effective and for each assessment year
that follows until the ensuing revaluation becomes effective.
   ‘‘(2) When conducting a revaluation, an assessor shall use generally
accepted mass appraisal methods which may include, but need not be limited
to, the market sales comparison approach to value, the cost approach to
value and the income approach to value. Prior to the completion of each
revaluation, the assessor shall conduct a field review. Except in a town that
has a single assessor, the members of the board of assessors shall approve,
by majority vote, all valuations established for a revaluation.
   ‘‘(3) An assessor, member of an assessor’s staff or person designated by
an assessor may, at any time, fully inspect any parcel of improved real
property in order to ascertain or verify the accuracy of data listed on the
assessor’s property record for such parcel. Except as provided in subdivision
(4) of this subsection, the assessor shall fully inspect each such parcel once
in every ten assessment years, provided, if the full inspection of any such
parcel occurred in an assessment year preceding that commencing October
1, 1996, the assessor shall fully inspect such parcel not later than the first
day of October of 2009, and shall thereafter fully inspect such parcel in
accordance with this section. Nothing in this subsection shall require the
assessor to fully inspect all of a town’s improved real property parcels in
the same assessment year and in no case shall an assessor be required to fully
inspect any such parcel more than once during every ten assessment years.
   ‘‘(4) An assessor may, at any time during the period in which a full
inspection of each improved parcel of real property is required, send a
questionnaire to the owner of such parcel to (A) obtain information concern-
ing the property’s acquisition, and (B) obtain verification of the accuracy
of data listed on the assessor’s property record for such parcel. An assessor
shall develop and institute a quality assurance program with respect to
responses received to such questionnaires. If satisfied with the results of
said program concerning such questionnaires, the assessor may fully inspect
only those parcels of improved real property for which satisfactory verifica-
tion of data listed on the assessor’s property record has not been obtained
and is otherwise unavailable. The full inspection requirement in subdivision
(3) of this subsection shall not apply to any parcel of improved real property
for which the assessor obtains satisfactory verification of data listed on the
assessor’s property record.’’
   2
     The other original plaintiffs in the present case are Mary B. Tuohy,
Robert Feery, Yola Feery, David W. Nickolenko, Sr., Charlene J. Nickolenko,
James J. Falcone, Linda A. Falcone, Louise H. Fisher, and Betsey F. Amador.
See also footnote 7 of this opinion.
   3
     General Statutes § 12-119 provides: ‘‘When it is claimed that a tax has
been laid on property not taxable in the town or city in whose tax list
such property was set, or that a tax laid on property was computed on an
assessment which, under all the circumstances, was manifestly excessive
and could not have been arrived at except by disregarding the provisions
of the statutes for determining the valuation of such property, the owner
thereof or any lessee thereof whose lease has been recorded as provided
in section 47-19 and who is bound under the terms of his lease to pay real
property taxes, prior to the payment of such tax, may, in addition to the
other remedies provided by law, make application for relief to the superior
court for the judicial district in which such town or city is situated. Such
application may be made within one year from the date as of which the
property was last evaluated for purposes of taxation and shall be served
and returned in the same manner as is required in the case of a summons
in a civil action, and the pendency of such application shall not suspend
action upon the tax against the applicant. In all such actions, the Superior
Court shall have power to grant such relief upon such terms and in such
manner and form as to justice and equity appertains, and costs may be
taxed at the discretion of the court. If such assessment is reduced by said
court, the applicant shall be reimbursed by the town or city for any overpay-
ment of taxes in accordance with the judgment of said court.’’
   4
     The plaintiffs appealed from the judgment of the trial court to the Appel-
late Court, and we transferred the appeal to this court pursuant to General
Statutes § 51-199 (c) and Practice Book § 65-1.
   5
     Unless otherwise noted, all references herein to the trial court are to
Judge Moll.
   6
     ‘‘The town is divided into thirteen residential neighborhoods. The term
‘neighborhood’ is defined in the revaluation regulations as ‘a geographic
area of complementary real property parcels that share similar locational
and market value characteristics, and may be defined by natural, man-made,
or political boundaries . . . .’ Regs., Conn. State Agencies § 12-62i-1 (13).’’
   7
     The trial court, Cohn, J., granted the plaintiffs’ motion for class certifica-
tion to make them representatives of a class that includes ‘‘[a]ll owners of
taxable residential real property with buildings thereon in . . . Groton Long
Point . . . between October 1, 2011, and July 1, 2013, excluding those own-
ers who individually appealed their real property tax assessments to the
Superior Court and whose appeals have reached a final judgment.’’
   8
     ‘‘With respect to [Groton Long Point], the land values were established
using three vacant lot sales.’’
   9
     ‘‘As part of this work, Tyler sent sales verification documents to the
town to determine whether there were any unknown features within the
validated sales set.’’
   10
      ‘‘Christy has conducted sales ratio studies by neighborhood, in addition
to townwide, in every revaluation she has handled.’’
   11
      ‘‘An ASR results from the comparison between the assessed value that
the CAMA program generates and the validated actual sale.’’
   12
      ‘‘Christy even testified that, in her view, to adopt the 1.2 adjustment
factor would have been unethical.’’
   13
      ‘‘The [international association] is an international group that adopts
standards that appraisers in revaluation use.’’
   14
      We note that the trial court’s memorandum of decision contains the
following finding: ‘‘After changing the 1.2 factor to a 1.35 factor, Tyler did
a ‘field review’ of all the values that resulted (meaning they went out and
reviewed every property in [Groton Long Point] to ensure that the new
computer generated values appeared to be full and fair market value for
the whole sample).’’ (Emphasis added.) This finding is, however, inconsistent
with the trial court’s subsequent observation that, ‘‘at the time Tyler [and
the] the town conducted the preliminary ratio tests that revealed a median
ASR of 88.31 percent for [Groton Long Point], they were satisfied with the
data collection concerning the [Groton Long Point] properties that had
occurred over the [eighteen] month period prior thereto and believed that
there was no need to physically reinspect each [Groton Long Point] prop-
erty.’’ (Emphasis added.) See footnote 18 of this opinion. We agree with the
plaintiffs that the first finding on this point is clearly erroneous, in contrast
to the second finding, which is supported by the record—namely, testimony
from both Christy and Gardner indicating that no physical inspection of
the subject properties was performed after Christy ran the various CAMA
scenarios and changed the adjustment factor from 1.2 to 1.35.
   15
      ‘‘The parties stipulated that, had the town applied a 1.0 factor to [Groton
Long Point], the resulting residential property class values would have
passed the ratio testing standards set forth in the OPM regulations.’’
   16
      The trial court, Miller, J., previously had denied the parties’ motions
for summary judgment, concluding that the ‘‘opinions of dueling appraisal
experts’’ presented a genuine issue of material fact with respect to the
manifest excessiveness of the assessments and whether the application of
the 1.35 factor to all of the properties in Groton Long Point disregarded
statutory requirements to ‘‘determine the true and actual valuation of each
individual property . . . .’’
   17
      OPM promulgated this regulation pursuant to General Statutes § 12-62
(g), which provides: ‘‘The secretary shall adopt regulations, in accordance
with the provisions of chapter 54, which an assessor shall use when conduct-
ing a revaluation. Such regulations shall include (1) provisions governing
the management of the revaluation process, including, but not limited to,
the method of compiling and maintaining property records, documenting
the assessment year during which a full inspection of each parcel of improved
real property occurs, and the method of determining real property sales
data in support of the mass appraisal process, and (2) provisions establishing
criteria for measuring the level and uniformity of assessments generated
from a revaluation, provided such criteria shall be applicable to different
classes of real property with respect to which a sufficient number of property
sales exist. Certification of compliance with not less than one of said regula-
tory provisions shall be required for each revaluation and the assessor shall,
not later than the date on which the grand list reflecting assessments of
real property derived from a revaluation is signed, certify to the secretary
and the chief executive officer, in writing, that the revaluation was conducted
in accordance with said regulatory requirement. Any town effecting a revalu-
ation with respect to which an assessor is unable to certify such compliance
shall be subject to the penalty provided in subsection (d) of this section.
In the event the assessor designates a revaluation company to perform mass
appraisal valuation or field review functions with respect to a revaluation,
the assessor and the employee of said company responsible for such function
or functions shall jointly sign such certification. The assessor shall retain
a copy of such certification and any data in support thereof in the assessor’s
office. The provisions of subsection (c) of this section concerning the public
inspection of criteria, guidelines, price schedules or statement of procedures
used in a revaluation shall be applicable to such certification and support-
ing data.’’
   18
      The trial court emphasized that the plaintiffs and their expert witness
had failed to cite any statute or regulation requiring such reinspection, and
credited Christy’s testimony that the defendants were ‘‘satisfied with the
data collection concerning the [Groton Long Point] properties that had
occurred over the [eighteen] month period prior thereto and believed that
there was no need to physically reinspect each [Groton Long Point] residen-
tial property.’’
   19
      The plaintiffs also posit that, to the extent that adjustment was required
because of Groton Long Point’s ‘‘unique’’ features and amenities, § 12-62
required the defendants to conduct individual assessments, particularly
because access to the amenities runs with the land, and the defendants
adjusted the value of the improvements, rather than the land.
   20
      ‘‘In Second Stone Ridge Cooperative Corp. v. Bridgeport, 220 Conn. 335,
339, 597 A.2d 326 (1991), we explained the distinction between municipal
tax appeals brought pursuant to § 12-119 and those authorized by General
Statutes § 12-117a, formerly codified at General Statutes § 12-118. While the
latter statute provide[s] a method by which an owner of property may
directly call in question the valuation placed by assessors upon his property
by an appeal to the board of [tax relief], and from it to the courts . . . § 12-
119 allows a taxpayer to claim either that a town lacked authority to tax
the subject property, or that the assessment was manifestly excessive and
could not have been arrived at except by disregarding the provisions of the
statutes for determining the valuation of [the real] property . . . . In short,
§ 12-117a is concerned with overvaluation, while [t]he focus of § 12-119 is
whether the assessment is illegal.’’ (Citations omitted; internal quotation
marks omitted.) Griswold Airport, Inc. v. Madison, 289 Conn. 723, 740, 961
A.2d 338 (2008).
   21
      The Uniform Standards of Professional Appraisal Practice was admitted
into evidence at trial as plaintiffs’ exhibit 17. We also note that the relevant
portions of this publication were reproduced in part II of the plaintiffs’
appendix to their brief filed in this appeal.
   22
      The Fundamentals of Mass Appraisal and the Standard on Ratio Studies
were admitted into evidence, respectively, as defendants’ exhibit 609 and
plaintiffs’ exhibit 16. We note that certain relevant portions of these publica-
tions were also reproduced in the appendices to the briefs submitted by
the parties in this appeal.
   23
      The Fundamentals observe that ‘‘[r]atio studies measure two primary
aspects of mass appraisal accuracy: level of valuation and uniformity of
values. Appraisal level refers to the overall, or typical, ratio at which proper-
ties are appraised relative to market value. In mass appraisal, appraised
values should not be expected always to equal independent indicators of
market value (sale prices or independent appraisals), but high and low ratios
should balance, so that the typical ratio is near 100 percent.’’ (Emphasis
in original.) Fundamentals of Mass Appraisal, supra, p. 198. In contrast,
‘‘[a]ppraisal uniformity relates to the extent to which appraisal procedures
produce logical and consistent results across individual properties. Unifor-
mity requires, first, that properties be appraised equitably within groups or
categories (use classes, neighborhoods, and so forth); that is, how close
are the individual ratios to the typical ratio (appraisal level)? Second, each
group of properties should be appraised at approximately the same level
or percentage of market value. In sum, appraisal uniformity requires equity
within groups and between groups.’’ Id. (Emphasis in original.)
   24
      ‘‘Direct equalization involves use of adjustment factors, which produce
effects mathematically identical to those derived through the application of
‘trending’ or ‘index’ factors, which are commonly used for value updating
by local assessing jurisdictions. The most significant differences typically
are the level of the jurisdiction originating the adjustments and the stratifica-
tion of property to which the factors are applied. Local jurisdictions with
primary assessment responsibility can develop value adjustment factors as
an interim step between complete reappraisals. Such factors commonly
are applied to properties by property type, location, size, age and other
characteristics . . . . It is rare for equalization factors developed by over-
sight agencies to be applied to strata more specific than property class or
broad geographic area. Often such factors are applied [jurisdiction wide].’’
(Citation omitted.) Standard on Ratio Studies, supra, p. 21.
   25
      In contrast to direct equalization, ‘‘[w]hen indirect equalization is used,
appraisals are not adjusted. Instead, indirect equalization involves an over-
sight agency estimating total taxable value, given the legally required level
of assessment or market value. Indirect equalization allows proper distribu-
tion of intergovernmental transfer payments between state or provincial and
local governments despite different levels of appraisal among jurisdictions
or property classes.’’ Standard on Ratio Studies, supra, p. 21.
   26
      The international association’s standards provide, for example, that
‘‘assuming that all classes of property are to be assessed at 100 [percent]
of market value, without such equalization, in a case [in which] residential
property is assessed at a median of 80 [percent] of market value, while
commercial property is assessed at a median of 90 [percent] of market
value, residential property will pay 80 [percent] of its proper tax share and
commercial property will pay 90 [percent] of its proper tax share. Other
classes that may be assessed at 100 [percent] will pay more than their
proper tax shares. Direct equalization mitigates this problem. However, such
equalization cannot improve uniformity between properties within a given
stratum. So, in the previous example, the median level of assessment for
residential property can be adjusted from 80 [percent] to 100 [percent] of
market value, assessment disparities between individual residential proper-
ties will not be addressed. For this reason, reappraisal orders should be
considered as the primary corrective tool for uniformity problems, and
direct equalization should be considered appropriate only if time or other
constraints preclude such an approach.’’ Standard on Ratio Studies, supra,
p. 22.
   27
      The court also observed that the assessor’s study itself revealed a wide
variety of undervaluation, from 28 to 45 percent, making it ‘‘clear that the
application of the 28 percent factor would not reflect the value of a particular
property based upon its individual characteristics as the statutes require.
Even for properties falling within the normal range of undervaluation, there
would be a substantial disproportion in the tax burden imposed on those
at the lower part of the range, which presumably would carry their full
share by application of the 28 percent factor, and those at the higher part
of the range which would not.’’ Chamber of Commerce of Greater Waterbury,
Inc. v. Waterbury, supra, 184 Conn. 338.
   28
      We note that the court rejected Waterbury’s argument that ‘‘even after
the application of the fixed percentage increase each of the affected proper-
ties has been valued at a figure not exceeding its fair market value.’’ Chamber
of Commerce of Greater Waterbury, Inc. v. Waterbury, supra, 184 Conn.
336. The court stated that ‘‘valuation of property in excess of fair market
value is not the only ground upon which a taxpayer may be entitled to relief.
. . . Any circumstances indicating that a disproportionate share of the tax
burden is being thrust upon a taxpayer would warrant judicial intervention.
. . . The plaintiffs claim that an illegal method of establishing assessments
for their properties has been followed, which has not been applied to other
taxpayers. If the challenged procedure is illegal, the plaintiffs must prevail.’’
(Citations omitted.) Id. Chamber of Commerce of Greater Waterbury, Inc.,
is not expressly a § 12-119 case, and does not even cite that statute. As
such, this portion of the analysis in that case is inconsistent with the well
established conjunctive test governing § 12-119, which requires proof of
both an illegal assessment and that the valuation is manifestly excessive.
See, e.g., Walgreen Eastern Co. v. West Hartford, supra, 329 Conn. 513–14.
   29
      Accordingly, we also find distinguishable the Superior Court cases on
which the plaintiffs rely, both of which were not mass appraisal cases
conducted under the international association’s standards. See Rand-Whit-
ney Containerboard L.P. v. Montville, Superior Court, judicial district of
New London, Docket No. CV-XX-XXXXXXX-S (October 30, 2006) (application of
lower depreciation rate solely to plaintiff’s property and no other taxpayers);
Yankee Gas Co. v. Meriden, Superior Court, judicial district of Tolland,
Complex Litigation Docket, Docket No. X07-CV-XX-XXXXXXX-S (April 20, 2001)
(29 Conn. L. Rptr. 285, 291) (creation of unique methodology aimed solely at
plaintiff’s property was equal protection violation actionable under § 12-119).
   30
      We emphasize that our analysis in this appeal is limited to the legality
of the mass appraisal methodology and does not determine the validity of any
individual property owners’ claims of overassessment pursuant to General
Statutes § 12-117a as a result of the application of an adjustment factor
during direct equalization. See footnote 20 of this opinion.
