The clause in a real estate document that defines the extent of ownership interest conveyed.

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 mean or the geometric mean.

An empirical rule that states that the value of a lot varies directly with the square root of its depth. For example, if a lot 100 feet deep is worth $100 per front foot, then a lot 49 feet deep is worth seven-tenths as much, or $70 per front foot. Compare Hoffman rule; 4-3-2-1rule; one-third, two-thirds rule.

Any substance designated under various federal acts as toxic or hazardous, including hazardous solid waste, toxic air pollutants, and imminently hazardous chemicals and mixtures. This term does not include petroleum and natural gas products or synthetic fuel gas.

A solid waste that may pose a present or potential hazard to health or to the environment. This includes any solid waste that is ignitable, corrosive, toxic, or reactive.

A facility that generates, stores, treats, or disposes of waste that is characterized as being hazardous by the EPA or state environmental and regulatory agency.

Unit of land measure equal to 100 meters square. Equivalent to 2,471 acres.

Hedonic pricing attempts to take observations of the overall goods or services and obtain implicit prices for the goods and services. Prices are measured in terms of quantity and quality. When valuing real property, the spatial attributes and property-specific attributes are valued in a single model. Calibration of the attribute components is performed statistically by regressing the overall price onto the characteristics.

Unlike; without interrelation. The opposite of homogeneous.

The quality of a dependent variable having inconstant variance for all values of the independent variables. The opposite of homoscedasticity.

A principle of appraisal and assessment requiring that each property be appraised as though it were being put to its most profitable use (highest possible present net worth), given probable legal, physical, and financial constraints. The principle entails first identifying the most appropriate market, and, second, the most profitable use within that market. The concept is most commonly discussed in connection with underutilized land.

A bar chart or graph of a frequency distribution in which the frequencies of the various classes are indicated by horizontal or vertical bars whose lengths are proportional to the number or percentage of observations in each class.

The number of years elapsed since an original structure was built. Synonyms are actual age and chronological age. See cost, original.

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

An extension of the Hoffman Rule to cover lots of depths other than half that of the standard lot.

The length of time an investor expects to own a given property before selling it to someone else.

See control sample.

A building occupied by the owner of the freehold and his or her family, with the primary intention of making it their home, together with the parcel of land on which it stands and the other improvements appurtenant to it. See estate of freehold. Note: This is a term variously defined by the several states and for several purposes. Most definitions pertain to the exemption of property from levy and sale and, as such, are not concerned with the nature of the estate that a householder owns in his or her home. The above definition, which is intended only for purposes of homestead tax exemption laws, requires further elaboration to indicate what constitutes a family, what constitutes occupancy primarily as a home, how large a parcel of land can be included as part of the homestead, and what constitutes an improvement appurtenant to the home. There is as yet no substantial agreement on these points among the states.

Possessing the quality of being alike in nature and therefore comparable with respect to the parts or elements; said of data if two or more sets of data seem to be drawn from the same population; also said of data if the data are of the same type (that is, if counts, ranks, and measures are not all mixed in together).

The quality of a dependent variable having constant variance for all values of the independent variables. For example, if regression residuals were plotted against living area, a band of uniform width would indicate homoscedasticity; a trapezoid would indicate heteroscedasticity.

Differences based on criteria other than value range in the levels of assessment of groups of properties. For example, properties in one neighborhood may have a higher level of assessment than similar properties in another neighborhood. See vertical inequity.

A geographic area where sales activity is unusually strong and, usually, market values are rising and assessment ratios are declining.

A model that incorporates both additive and multiplicative components. See also additive model and multiplicative model.

A statement in inferential statistics the truth of which one is interested in determining. The usual procedure is to state what one chooses to accept in the absence of sufficient evidence to the contrary (the statement is called the null hypothesis), specify the relationship or statement to be proved (the alternative hypothesis), and analyze the available data to determine whether the null hypothesis can be rejected (and hence the alternative hypothesis accepted) at some confidence level.