- Object of Tax(1) The objective element on which a tax is imposed. (2) The aims or purposes for which the tax is designed. Note: This term, as defined in (1) above, does not seem to be distinguished adequately from "measure of tax," "subject of tax," and "tax base." Such distinction as can be drawn is pedantic, and the use of the term in this sense is not recommended. It is also recommended that the term "purpose of tax" be substituted for the second usage given above. Compare measure of tax; subject of tax; tax base.
- Objective DataObjective data are variables for which the correct value can be verified. Examples include zoning, corner lot (yes or no), land area, and front feet.
- ObservationOne recording or occurrence of the value of a variable, for example, one sale ratio among a sample of sales ratios.
- ObsolescenceA decrease in the value of a property occasioned solely by shifts in demand from properties of this type to other types of property and/or to personal services. Some of the principal causes of obsolescence are (1) changes in the esthetic arts; (2) changes in the industrial arts, such as new inventions and new processes; (3) legislative enactments; (4) change in consumer demand for products that results in inadequacy or over- adequacy; (5) migration of markets that results in misplacement of the property. Contrast depreciation, physical; depreciation, economic.
- OccupancyThe act of taking or holding possession of property.
- Opportunity CostThe principle that the cost of a resource for one use is the value of the resource in its best alternative use.
- OutlierInstances of extreme undervaluation or overvaluation compared against a known value.
- OutliersObservations that have unusual values, that is, they differ markedly from a measure of central tendency. Some outliers occur naturally; others are due to data or modeling errors.
- Outputs(1) Goods produced by a firm. (2) The information returned by a computer to its user.
- OverimprovementAn improvement whose cost exceeds the cost of an alternative improvement by more than the excess of the present worth of the given improvement and the land over the present worth of the alternative improvement and the land, often because a structure is too large or too costly for the most profitable use of the site. Contrast underimprovement.
- OwnershipThe rights to the use of property, to the exclusion of others.
b) AVMs 201: A Practical Guide to the Implementation of Automated Valuation Models, Jim Kirchmeyer, 2008.
d) Collateral Assessment & Technologies Committee, Summary of Definitions & Terms, 2006.
e) Joint Industry Task Force on AVMs, IAAO Standard on AVM Glossary, September 2003. https://www.iaao.org/media/standards/AVM_STANDARD.pdf
f) Appraisal Institute, Joint Industry Task Force on Automated Valuation Models, Work Group Terminology, 2005.
g) Merriam-Webster (https://www.merriam-webster.com/)