ABOVE GRADE LIVING AREA; AGLA 

The living area in a house not including the basement.

ACCESSORY IMPROVEMENTS.
Improvements other than the principal buildings.

AD VALOREM TAX 

A tax levied in proportion to the value of the thing(s) being taxed. Exclusive of
exemptions, usevalue assessment provisions, and the like, the property tax is an
ad valorem tax.

AD VALOREM 
 According to value.

ADJUSTMENTS 
 Modifications in the reported value of a
variable, such as sale price. For example, adjustments can be used to
estimate market value in the sales comparison approach by modifications
for differences between comparable and subject properties.

APPRAISAL DATE 

The date as of which a property's value is estimated.

APPRAISAL RATIO STUDY 

A ratio study using independent appraisals as indicators of market value.

APPRAISAL RATIO 
 (1) The ratio of the appraised value to an indicator of market value.
(2) By extension, an estimated fractional relationship between the appraisals and market values
of a group of properties.

APPRAISAL REPORT 

The oral or written communication of a completed appraisal.

APPRAISAL STANDARDS BOARD 
 The division of the APPRAISAL FOUNDATION that develops,
publishes, interprets, and amends the
Uniform Standards of Professional Appraisal
Practice on behalf of appraisers and users of appraisal services.

APPRAISAL 
 (1) The act of estimating the money value of property.
(2) the money value of property as estimated by an appraiser.
(3) Of or pertaining to appraising and related functions, for example, appraisal practice,
appraisal services. Compare assessment.

APPRAISALSALE PRICE RATIO 
 The ratio of the appraised value to the sale price
(or adjusted sale price) of a property; a simple indication of appraisal accuracy.

APPRAISER 
 One who estimates the value of property; more
commonly, one of a group of professionally skilled persons holding themselves out as
experts in valuation.

AREA. A geographic area defined and named by the Department of Assessments.
These areas typically encompass properties within a group of neighborhoods that are more or less
equally subject to economic forces that largely determine the value of the properties in question.

ASSESSED VALUE 

A value set on real estate and personal property by a government as a basis for levying taxes.

ASSESSMENT EQUITY 
 The degree to which assessments
bear a consistent relationship to market value.

ASSESSMENT LEVEL 

The common or overall ratio of assessed values to market values.

ASSESSMENT PROGRESSIVITY 

An appraisal bias such that highvalue properties are appraised higher than lowvalue properties in
relation to market values.

ASSESSMENT RATIO 
 (1) The fractional relationship an assessed value bears
to the market value of the property in question. (2) By extension, the fractional relationship the total
of the assessment roll bears to the total market value of all taxable property in a jurisdiction.
See level of assessment.

ASSESSMENT REGRESSIVITY 
 An appraisal bias such that
highvalue properties are appraised lower than lowvalue properties in relation to market values.

ASSESSMENT 

(verb) The official act of discovering, listing, and appraising property.
(noun) The value placed on property in the course of such act.

ASSESSMENTSALE PRICE RATIO 

The ratio of the assessed value to the sale price (or adjusted sale price) of a property.

AVERAGE DEVIATION 

The arithmetic mean of the absolute
deviations of a set of numbers from a measure of central tendency, such as the median.
Taking absolute values is generally understood without being stated. The average of the
numbers 4,6, and 10 about their median (6) is (2+0+4)/3 =2. The average deviation is used
in computing the coefficient of dispersion.

BIAS 
 A statistic is said to be biased if the expected value of that statistic is
not equal to the population parameter being estimated. A process is said to be biased
if it produces results that vary systematically with some factor that should be
irrelevant. In assessment administration, assessment progressivity (regressivity)
is one kind of possible bias.

BUILDING CONDITION 
 Relative to age and grade. Coded 15.
1 = Poor Worn out. Repair and overhaul needed on painted surfaces, roofing, plumbing, heating and numerous functional inadequacies.
Excessive deferred maintenance and abuse, limited valueinuse, approaching abandonment or major reconstruction;
reuse or change in occupancy is imminent. Effective age is near the end of the scale regardless of the actual
chronological age.
2 = Fair Badly worn. Much repair needed. Many items need refinishing or overhauling, deferred maintenance
obvious, inadequate building utility and systems all shortening the life expectancy and increasing the effective
age.
3 = Average Some evidence of deferred maintenance and normal obsolescence with age in that a few minor repairs
are needed, along with some refinishing. All major components still functional and contributing toward an
extended life expectancy. Effective age and utility is standard for like properties of its class and usage.
4 = Good No obvious maintenance required but neither is everything new. Appearance and utility are above the
standard and the overall effective age will be lower than the typical property.
5= Very Good All items well maintained, many having been overhauled and repaired as they have shown signs of
wear, increasing the life expectancy and lowering the effective age with little deterioration or obsolescence
evident with a high degree of utility.

BUILDING GRADE 
 Represents the construction quality of improvements. Grades run from grade
1 to 13. Generally defined as:
13  Falls short of minimum building standards. Normally cabin or inferior structure 
4  Generally older, low quality construction. Does not meet code. 
5  Low construction costs and workmanship. Small, simple design. 
6  Lowest grade currently meeting building code. Low quality materials and simple designs. 
7  Average grade of construction and design. Commonly seen in plats and older subdivisions. 
8  Just above average in construction and design. Usually better materials in both the exterior and interior finish work. 
9  Better architectural design with extra interior and exterior design and quality. 
10  Homes of this quality generally have high quality features. Finish work is better and more design quality is seen in the floor plans. Generally have a larger square footage. 
11  Custom design and higher quality finish work with added amenities of solid woods, bathroom fixtures and more luxurious options. 
12  Custom design and excellent builders. All materials are of the highest quality and all conveniences are present. 
13  Generally custom designed and built. Mansion level. Large amount of highest quality cabinet work, wood trim, marble, entry ways etc. 

CENTRAL TENDENCY 
 (1) The tendency of most kinds of
data to cluster around some typical or central value, such as the mean, median, or mode.
(2) By extension, any or all such statistics.

CHARACTERISTICSBASED MARKET ADJUSTMENT 
 A market adjustment model which uses
previous assessed value along with property characteristics. The basic model form
is Sale Price = Prior Year Assessed Value * (1 / factor 0 + (factor1 * Char 1) + (factor2 * Char2)…+(factorN*CharN) ),
where Char1 and so on are items such as building grade, lot size and so forth. The influence
of these characteristics must be statistically significant over and above any statistical
relationship the prior year assessed value bears on sales prices.

COEFFICIENT OF DISPERSION (COD).
The average deviation of a group of numbers from the median expressed as a
percentage of the median. In ratio studies, the average percentage deviation from
the median ratio. It is a measure of uniformity.

COEFFICIENT OF VARIATION (COV) 
 A standard statistical measure of the relative dispersion of the sample data about the mean of the data; the standard deviation expressed as a percentage of the mean. It is a measure of uniformity.

COEFFICIENT 

(1) In a mathematical expression, a number or letter preceding and multiplying another
quantity. For example, in the expression, 5X, 5 is the coefficient of X, and in the
expression aY, a is the coefficient of Y. (2) A dimensionless statistic, useful as
a measure of change or relationship; for example, correlation coefficient.

COMPARABLES SALES; COMPARABLES 

(1) Recently sold properties that are similar in important respects to a property
being appraised. The sale price and the physical, functional, and locational
characteristics of each of the properties are compared to those of the property
being appraised in order to arrive at an estimate of value.
(2) By extension, the term "comparables" is sometimes used to refer to properties
with rent or income patterns comparable to those of a property being appraised.

CONFIDENCE INTERVAL 

For a given confidence level, the range within which one can conclude that a
measure of the population (such as the median or mean appraisal ratio) lies.

CONFIDENCE LEVEL 

The required degree of confidence in a statistical test or confidence interval;
commonly 90, 95, or 99 percent. A 95 percent confidence interval would mean, for
example, that one can be 95 percent confident that the population measure (such as
the median or mean appraisal ratio) falls in the indicated range. It is a measure
of assessment reliability.

CORRELATION 

A statistical phenomenon (and a technique for estimating its strength) whereby
knowledge of one fact about a thing implies some knowledge of a second fact about
that thing. For example, because the volume and weight of water are correlated,
knowing that a quantity of water is one gallon also means knowing that its weight
is eight and onethird pounds. Linear correlation, the kind most often encountered,
means that an increase in one factor
in some proportion (say, a doubling) changes the other in the same proportion.
With curvilinear correlation, as between the radius and the area of a circle,
this is not true, despite the fact that the correlation may be very strong in
the sense that knowledge of one fact tells you precisely the other fact. These are
examples of variables perfectly correlated or nearly so; more often, correlation is
only partial – for example, the correlation between the age and height of a child.
The correlation coefficient gives the strength of the linear relationship between the
two variables.

COST APPROACH 
 One of the three approaches to value, the cost approach is based on the principle of substitution – that a rational, informed purchaser would pay no more for a property than the cost of building an acceptable substitute with utility. The cost approach seeks to determine the replacement cost new of an improvement less depreciation plus land value.

DATA 
 Information expressed in any of a number of ways.
"Data" is the general term for masses of numbers, codes, and symbols generally, and
"information" is the term for meaningful data. "Data" is the plural of datum, one
element of data.

DEMAND 
 The amount of a good or service that would be
purchased at various prices during a given period.

DISPERSION 
 The degree to which data are distributed
either tightly or loosely around a measure of central tendency. Measures of
dispersion include the average deviation, coefficient of dispersion, coefficient of
variation, range, and standard deviation.

FACTOR 
 (1) An underlying characteristic of something
(such as a house) that may contribute to the value of a variable (such as its
sale price), but is observable only indirectly. For example, construction quality
is a factor defined by workmanship, spacing of joists, and materials used. Factor
definition and measurement may be done subjectively or by a computerassisted
statistical algorithm known as factor analysis. (2) Loosely, any characteristic
used in adjusting the sales prices of comparables.

FILTER COUNT 
 Is located in the last column of your search results.
This column lets you know the total number of sales remaining after each search criteria was applied.
You may need to modify the search criteria to return more sales or reduce the number of sales returned.
Use the Filter Count as a guide for what search criteria to change.

GRADE 

Classification by construction quality which refers to the types of
materials used and the quality of workmanship. Buildings of better quality
(higher grade) cost more to build per unit of measure and command higher value.
(See Glossary in Area Report for Residential Building Grades in use by the King
County Department of Assessments.)

IMPROVEMENT 
 Anything done to raw land with the
intention of increasing its value. A structure erected on the property constitutes
one very common type of improvement, although other actions, such as those taken to
improve drainage, are also improvements.

IMPROVEMENTS 
 Buildings, other structures,
and attachments or annexations to land that are intended to remain so attached or
annexed, such as sidewalks, trees, drives, tunnels, drains and sewers.

LEVEL OF ASSESSMENT; ASSESSMENT RATIO 
 The common or overall ratio of assessed
values to market values.

LIEN DATE 
 The date on which an obligation, such as a
property tax bill (usually in an amount yet to be determined), attaches to a
property and the property thus becomes security against its payment. The term is
usually synonymous with appraisal date but is not necessarily so.

MARKET AREA 

A geographic area, typically encompassing
a group of neighborhoods, defined on the basis that the properties within its
boundaries are more or less equally subject to a set of one or more economic forces
that largely determine the value of the properties in question.

MARKET VALUE 

Market value is the major focus of most
real property appraisal assignments. Both economic and legal definitions of market
value have been developed and refined.

MASS APPRAISAL MODEL 
 A mathematical expression of how supply and demand factors
interact in a market.

MASS APPRAISAL 
 The process of valuing a group of
properties as of a given date, using standard methods, employing common data, and
allowing for statistical testing.

MEAN 
 A measure of central tendency. The result of adding all the values of a
variable and dividing by the number of values. For example, the mean of 3,5, and 10
is 18 divided by 3, or six. Also called arithmetic mean.

MEDIAN 

A measure of central tendency. The value of the
middle term in an uneven number of items arranged or arrayed according to size;
the arithmetic average of the two central items in an even number of items similarly
arranged; a positional average that is not affected by the size of extreme values.
The median of 3,5, and 10 is 5. The middle number.

MODEL CALIBRATION 
 The development of adjustments,
or coefficients based on market analysis, that identifies specific factors with an
actual effect on market value.

MODEL SPECIFICATION 

The formal development of a model in a statement or equation,
based on data analysis and appraisal theory.

MODEL 
 (1) A representation of how something works. (2) For purposes of appraisal,
a representation (in words or an equation) that explains the relationship between
value or estimated sale price and variables representing factors of supply and demand.

NORMAL DISTRIBUTION 
 A theoretical distribution often approximated in realworld situations.
It is symmetrical and bellshaped; 68 percent of the observations occur within one
standard deviation of the mean, and 95 percent within two standard deviations.

OBSERVATIONS 
 One recording or occurrence of the value
of a variable, for example, one sale ratio among a sample of sales ratios.

PRESENT USE 

Usually represents the current use of the property.

PHYSICAL INSPECTION 
 At a minimum, an exterior
observation of the property to determine whether there have been any changes in the
physical characteristics that affect value. The property improvement record must be
appropriately documented in accordance with the findings of the physical inspection.
(Defined in WAC 45807015).

POPULATION. All the items of interest, for example, all
the properties in a jurisdiction or neighborhood; all the observations in a data set
from which a sample may be drawn.

PRICERELATED DIFFERENTIAL (PRD) 
 The mean
divided by the weighted mean. The statistic has a slight bias upward. Pricerelated
differentials above 1.03 tend to indicate assessmentregressivity; pricerelated
differentials below 0.98 tend to indicate assessment progressivity. It is a measure of
assessment equity.

RANGE 

(1) The maximum value of a sample, minus the minimum value.
(2) The difference between the maximum and minimum values that a variable may assume.

RATIO STUDY 
 A study of the relationship between appraised
or assessed values and market values. Indicators of market values may be either
sales or independent "expert" appraisals. Of common interest in ratio studies are
the level and uniformity of the appraisals or assessments. See also level of
appraisal and level of assessment.

REAL PROPERTY 

In Washington the law states:
"The term "real property" for the purposes of taxation shall be held and construed
to mean and include the land itself, whether laid out in town lots or otherwise,
and all buildings, structures or improvements or other fixtures of whatsoever kind
thereon, except improvements upon lands the fee of which is still vested in the
United States, or in the state of Washington, and all rights and privileges thereto
belonging or in any wise appertaining, except leases of real property and leasehold
interests therein for a term less than the life of the holder; and all substances
in and under the same; all standing timber growing thereon, except standing timber
owned separately from the ownership of the land upon which the same may stand or be
growing; and all property which the law defines or the courts may interpret,
declare and hold to be real property under the letter, spirit, intent and meaning
of the law for the purposes of taxation. The term real property shall also include
a mobile home which has substantially lost its identity as a mobile unit by virtue
of its being permanently fixed in location upon land owned or leased by the owner
of the mobile home and placed on a permanent foundation (posts or blocks)
with fixed pipe connections with sewer, water, or other utilities: PROVIDED,
That a mobile home located on land leased by the owner of the mobile home shall
be subject to the personal property provisions of chapter
84.56 RCW and RCW
84.60.040." (RCW 84.04.090)

REAPPRAISAL CYCLE 
 (1) The period of time
necessary for a jurisdiction to have a complete reappraisal. For example, a cycle
of five years occurs when onefifth of a jurisdiction is reappraised each year and
also when a jurisdiction is reappraised all at once every five years. (2)
The maximum interval between reappraisals as stated in laws.

RELATIONSHIP 
 The phenomenon whereby knowledge of the value of one variable tells
you something about the probable value of another. (See correlation).
Relationships may be positive (an increase in the value of one variable implies an
increase in the value of the other variable) or negative (a change in the value of one
variable implies a change in the other direction for the value of the other variable).
Independence of two variables means that there is no relationship between them.

REPLACEMENT COST NEW LESS DEPRECATION (RCNLD) 
 I
n the cost approach, replacement cost new less physical incurable depreciation.

REPLACEMENT COST; REPLACEMENT COST NEW 
 The cost,
including material, labor, and overhead, that would be incurred in constructing an
improvement having the same utility to its owner as a subject improvement, without
necessarily reproducing exactly any particular characteristics of the subject. The
replacement cost concept implicitly eliminates all functional obsolescence from the value
given; thus only physical depreciation and economic obsolescence need to be subtracted to
obtain replacement cost new less depreciation (RCNLD).

REPRESENTATIVE SAMPLE 
 A sample of observations
from a larger population of observations, such that statistics calculated from the sample
can be expected to represent the characteristics of the population being studied.

REVALUATION CYCLE 
 Each county assessor shall cause
taxable real property to be physically inspected and valued at least once every six years
in accordance with RCW
84.41.030, and in accordance with a plan filed with and approved by the department
of revenue. Such revaluation plan shall provide that a reasonable portion of all taxable
real property within a county shall be revalued and these newlydetermined values placed
on the assessment rolls each year. The department may approve a plan that provides that
all property in the county be revalued every two years. If the revaluation plan provides
for physical inspection at least once each four years, during the intervals between each
physical inspection of real property, the valuation of such property may be adjusted to
its current true and fair value, such adjustments to be based upon appropriate statistical
data. If the revaluation plan provides for physical inspection less frequently than once
each four years, during the intervals between each physical inspection of real property,
the valuation of such property shall be adjusted to its current true and fair value, such
adjustments to be made once each year and to be based upon appropriate statistical data.
The assessor may require property owners to submit pertinent data respecting taxable
property in their control including data respecting any sale or purchase of said property
within the past five years, the cost and characteristics of any improvement on the property
and other facts necessary for appraisal of the property.(RCW 84.41.041)

SAMPLE 

A set of observations selected from a population.

SALES WARNINGS. Sales verification information that identifies
something out of the ordinary on a sale.

STANDARD DEVIATION 
 The statistic calculated from
a set of numbers by subtracting the mean from each value and squaring the remainders,
adding together all the squares, dividing by the size of the sample less one, and taking
the square root of the result. When the data are normally distributed, one can calculate
the percentage of observations within any number of standard deviations from normal
probability tables. When the data are not normally distributed, the standard deviation is
less meaningful, and one should proceed cautiously.

STANDARDS OF PRACTICE 
 The standards of practice
adopted by the department and governing real property appraisal activities by accredited
appraisers are the generally accepted appraisal standards as evidenced by the current
appraisal standards promulgated by the Appraisal Standards Board of the Appraisal Foundation.
A complete text of these appraisal standards is available for viewing during normal
working hours at the property tax division of the department (WAC 45810060).

SUB AREA. A smaller appraisal market in a geographical area. To limit your
search to a sub area, you will need to know a parcel number that is in the geographical area of interest.

SUPPLY 

The amount of a good or service that would be offered
for sale at various prices during a given period.

TAX YEAR 

Properties are assessed as of January 1 of any given year for taxes paid
the following year. For example, properties assessed in 2004 will pay taxes in 2005.

TOTAL LIVING AREA 
 Total finished living space. This would include
finished space in a basement.

TRUE AND FAIR VALUE 
 In Washington, all property must
be valued and assessed at one hundred percent of true and fair value unless otherwise
provided by law. "True and fair value" means market value and is the amount of money a
buyer of property willing but not obligated to buy would pay a seller of property willing
but not obligated to sell, taking into consideration all uses to which the property is
adapted and might in reason be applied. (WAC 45807030 (1) ).

UNIFORM STANDARDS OF PROFESSIONAL APPRAISAL PRACTICE


Annual publication of the Appraisal Standards board of the Appraisal Foundation:
"These Standards deal with the procedures to be followed in performing an appraisal,
review or consulting service and the manner in which an appraisal, review or consulting
service is communicated….STANDARD 6 sets forth criteria for the development and reporting
of mass appraisals for ad valorem tax purposes or any other universe of properties" (p.1).

UNIFORMITY 

The equality of the burden of taxation in the method of assessment.

VARIABLE 

An item of observation that can assume various values, for example, square feet,
sales prices, or sales ratios. Variables are commonly described using measures of
central tendency and dispersion.

WEIGHTED MEAN RATIO 

Sum of the appraised values divided by the sum of the sales prices, which weights
each value in proportion to its sale price. It is a better reflection of the sample
than the arithmetic mean.

WEIGHTED MEAN; WEIGHTED AVERAGE 

An average in which each value is adjusted by a factor reflecting its relative
importance in the whole before the values are summed and divided by their number.
