Based on the quality of data, AccuriZ can produce different statistical reports to provide a macro overview of a community or for specific purposes, detailed statistical reports can be produced given specific levels of stratification. Some common statistical studies are as follows:

AccuriZ provides a scientific, unbiased approach for independent valuation. This approach is the culmination of years of experience and rigorous research using proprietary series of algorithms to deliver the most accurate results- results that are not just close but precise.

AccuriZ follows a procedural structure aimed at delivering property valuation estimates that represent the most accurate market value for the period defined. The most critical element in property valuation is the physical data that exists for a property. Proprietary algorithms that have been developed over years of testing enable AccuriZ to clean and stratify data so that accurate valuation estimates can be produced.

When operating in a vacuum, the absence of data yields a poor valuation. At AccuriZ, we operate with precision, not in a vacuum. Our analysis of property sales dating back to 1990 enables AccuriZ to develop a powerful time-line covering the past 16 years. The reporting available as a result provides real estate trends by zip code throughout New York State (and soon in other regions as well).

An empirical rule that ascribes 40 percent of the value of a standard lot (see lot, standard) to the quarter of the lot fronting on the street, 30 percent to the next quarter, 20 percent to the third quarter, and 10 percent to the rear quarter. Compare Harper rule; Hoffman rule; one-third, two-thirds rule. Note: Lots with a depth greater than the standard lot cannot be valued in accordance with this rule as stated above. The rule is sometimes altered by omitting the word "standard." It thereby becomes applicable to extra deep lots but produces inconsistent results as applied to lots of varying depths.

Rule states that the value of a triangular lot with its base on the facing street will be approximately 65 percent of that of a rectangular lot of the same frontage and depth. The value of the triangular lot with its apex on the facing street will be 35 percent of that of a rectangular lot of the same base and depth.

A model in which the dependent variable is estimated by multiplying each independent variable by its coefficient and adding each product to a constant.

A computerized, iterative, self-referential procedure using properties for which sales prices are known to produce a model that can be used to value properties for which sales prices are not known. Also called "feedback."

Statistics used in multiple regression analysis and other kinds of statistical modeling to express the amount, and hence the importance, of the errors or residuals for all the predicted and actual values of a variable.

The reciprocal of the arithmetic mean of the reciprocals of each value in the data set. The harmonic mean ratio is less affected by extreme values in the data set than the arithmetic

A test in inferential statistics, valid for all types of numerical data, that seeks to determine whether the observations in a sample came from one population as opposed to three or more distinct, homogeneous subpopulations. This test is used in assessment to analyze assessment ratios from three or more classes of property to determine whether significant assessment biases are present among the classes of property. When only two classes are being compared, the appropriate test is the Mann-Whitney test.

Any of a family of possible ways of measuring distance. Euclidean distance, a member of this family, computes straight-line distances (as the crow flies) by squaring differences in like coordinates, summing them, and taking the square root of the sum. In mass appraisal model building, Minkowski metric usually refers to the sum of absolute differences (not squared) in each dimension, and resembles a "taxicab" or city block pattern. Other alternatives are possible, including the distance as calculated only for the dimension of greatest difference, but the city block distance is most common.

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

A mathematical model in which the coefficients of independent variables serve as powers (exponents) to which the independent variables are raised or in which independent variables themselves serve as exponents; the results are then multiplied to estimate the value of the dependent variable.

Any of a number of statistical analysis in which data (such as the information on a single property record card) containing a number of variables (such as lot size, number of rooms, and construction type) are analyzed to predict the value of some other variable. See also multiple regression analysis.

This divides depreciation into all its various components-curable physical deterioration, incurable short-lived-item physical deterioration, incurable basic structure (long-lived items) physical deterioration, curable functional obsolescence, incurable functional obsolescence, and economic (external) obsolescence-often for each major building component.

An empirical rule that ascribes half of the value of a lot to the front third and the other half to the rear two-thirds. Compare 4-3-2-1 rule; Harper rule; Hoffman rule.

The coefficient calculated by the regression algorithm for the data supplied that, when multiplied by the value of the variable with which it is associated, will predict (for simple regression) or help to predict (for multiple regression) the value of the dependent variable. For example, in the equation, Value = $10,000 + $5,000 + number of rooms, $5,000 is a regression coefficient.

The line on a graph that represents the relationship defined by the regression coefficients. For example, the line from the relationship given in the definition of regression coefficient would cross the y-axis at the value $10,000 and would go up $5,000 for each movement of 1 to the right. This example illustrates one of the subtleties required in understanding regression analysis: in fact, there is no line, because the independent variable is not a continuous variable, but it is easier to talk about the relationship by pretending that the variable is continuous and represent the relationship by a line rather than the more nearly correct series of vertical bars on a bar chart.

See assessment progressivity (regressivity).

The square root of the average value of the sum of the squares of the differences between values in a set and the corresponding values that have been accepted as correct or standard. Used to measure map accuracy.

A corner influence graph devised by John A. Zangerle, showing, for any given main street frontage, the percentage of the side street value to be added as corner influence to the value of the lot computed as an inside lot fronting on the main street. Compare Bernard rule.