442 Neb. Admin. Code, ch. 9, § 002
The following definitions apply whenever the defined term is used in this chapter or the Commission's orders unless the context of a term's use requires use of a different definition.
An applicable time frame is the period from which sales may be drawn for statistical studies.
An assessment/sales ratio is a tool used under professionally accepted mass appraisal methods to measure and evaluate the level and uniformity of assessed values. The ratio is determined by dividing the assessed value of a parcel of real property by the sales price of that parcel. The phrase may also refer to the total assessed value of all real property parcels of a particular class or subclass of real property sold during a particular time frame divided by the total sales price of all real property parcels of that class or subclass sold during that same time frame. The assessment/sales ratio is expressed in terms of a percentage.
A group of properties that share one or more characteristics typically common to all properties in the class or subclass, but are not typically found in the properties outside the class or subclass. Class or subclass includes, but is not limited to classifications of agricultural land and horticultural land in section 77-1363 (irrigated cropland, dryland cropland, grassland, wasteland, nurseries, feedlots and orchards), parcel use, parcel type, location, geographic characteristics, zoning, city size, and market characteristics for all classifications of land so that the categories reflect uses appropriate for the valuation of such land, a class or subclass based on market characteristics shall be based on characteristics that affect the actual value in a different manner than it affects the actual value of properties not within the market characteristic class or subclass. Neb. Rev. Stat. 77-103.01
The Coefficient of Dispersion ("COD") is a tool used under professionally accepted mass appraisal methods to measure the uniformity of assessments. The COD is the average absolute deviation from the median stated as a percentage. The COD is calculated by dividing the average absolute deviation by the median assessment/sales price ratio and multiplying by 100 to convert the ratio to a percentage.
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.
A range of values, calculated from the sample observations that are believed, with a probability, to contain the true population parameter (mean, median, COD). The confidence interval is not a measure of precision of the sample statistic or point estimate, but a measure of the precision of the sampling process (See Reliability).
The degree of probability associated with a statistical test or confidence interval. For example, a 95 percent confidence interval implies that were the estimation process repeated again and again, then 95 percent of the calculated intervals would be expected to contain the true measure of a parameter(such as the median, mean, or COD). A stated probability level refers to the properties of the interval and not to the parameter itself.
An indicator of central tendency utilized in generally accepted professional mass appraisal techniques
Those techniques and methods described as professionally accepted mass appraisal techniques and methods. See Chapter 2, § 001.46 of these rules.
The result of measuring the tendency of most kinds of data to cluster around some typical or central value. Indicators of central tendency include the mean, median, and mode.
The common or overall ratio of assessed values to market values.
The mean is a measure of central tendency. The mean is the result of adding all of the values of an array and dividing by the number of values.
The median is a measure of central tendency. The median is the value of the middle item 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 mode is a measure of central tendency. In an array of values the mode is the most frequently occurring value.
The Price Related Differential ("PRD") is a tool used under professionally accepted mass appraisal methods to determine whether properties of differing values are treated uniformly. The Price Related Differential may indicate assessment bias and inequity between lower valued properties and higher valued properties. A PRD that is under 1.00 indicates higher valued properties are valued at a higher assessment level than lower valued properties. When the PRD is over 1.00 it indicates lower valued properties are valued at a higher level than higher valued properties.
Property whose taxable value is determined by the Property Tax Administrator and/or the Tax Commissioner.
In a sampling process, the extent to which the process yields consistent population estimates. Ratio studies are typically based on samples. Statistics derived from these samples may be more or less likely to reflect the true condition in the population depending on the precision or reliability of the sample.
Representativeness, sample size, and sample uniformity all contribute to reliability. Formally reliability is measure by sampling error or the width of the confidence interval at a specific confidence level relative to the central tendency.
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.
A ratio study that uses sales prices as proxies for market values.
A set of observations selected from a population. If the sample was randomly selected, basic concepts of probability may be applied.
The error reflected in ratio study statistics that results solely from the fact that a sample population is used rather than a census of the population.
The statistic calculated from a set of numbers by subtracting the mean from each value and squaring the remainders, adding together all of 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 of the mean from normal probability tables. When the data are not normally distributed, the standard deviation is less meaningful.
A measure of the precision of a measure of central tendency; the smaller the standard error, the more reliable the measure of central tendency. Standard errors are used in calculation of a confidence interval about the arithmetic mean and the weighted mean.
Numerical descriptive data calculated from a sample, for example, the median, mean, or coefficient of dispersion. Statistics are used to estimate corresponding measures termed parameters, for the population.
Counties, townships, cities, villages, school districts, and all other subdivisions of the state and all governmental agencies having the power to levy or to provide for the levy of general or special taxes.
Changes made to the sales price of real property sold during a particular time frame in order to account for general changes in market value.
442 Neb. Admin. Code, ch. 9, § 002