An attribute-value system is a basic knowledge representation

Knowledge representation

Knowledge representation is an area of artificial intelligence research aimed at representing knowledge in symbols to facilitate inferencing from those knowledge elements, creating new elements of knowledge...

 framework comprising a table with columns designating "attributes" (also known as "properties", "predicates," "features," "dimensions," "characteristics" or "independent variables" depending on the context) and rows designating "objects" (also known as "entities," "instances," "exemplars," "elements" or "dependent variables"). Each table cell therefore designates the value (also known as "state") of a particular attribute of a particular object.

Example of attribute-value system

Below is a sample attribute-value system. It represents 10 objects (rows) and five features (columns). In this example, the table contains only integer values. In general, an attribute-value system may contain any kind of data, numeric or otherwise. An attribute-value system is distinguished from a simple "feature list" representation in that each feature in an attribute-value system may possess a range of values (e.g., feature below, which has domain of {0,1,2}), rather than simply being present or absent .

Sample Attribute-Value System

Object
	1	2	0	1	1
	1	2	0	1	1
	2	0	0	1	0
	0	0	1	2	1
	2	1	0	2	1
	0	0	1	2	2
	2	0	0	1	0
	0	1	2	2	1
	2	1	0	2	2
	2	0	0	1	0

Other terms used for "attribute-value system"

Attribute-value systems are pervasive throughout many different literatures, and have been discussed under many different names:

• Flat data
• Spreadsheet
  Spreadsheet
  A spreadsheet is a computer application that simulates a paper accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. Each cell contains alphanumeric text, numeric values or formulas...
  
  
• Attribute-value system (Ziarko & Shan 1996)
• Information system (Pawlak 1981)
• Classification system (Ziarko 1998)
• Knowledge representation system (Wong & Ziarko 1986)
• Information table (Yao & Yao 2002)
• Object-predicate table (Watanabe 1985)
• Aristotelian table (Watanabe 1985)
• Simple frames
• First normal form
  First normal form
  First normal form is a normal form used in database normalization. A relational database table that adheres to 1NF is one that meets a certain minimum set of criteria...
  
  database

See also

• Bayes networks
• Entity-attribute-value model
  Entity-Attribute-Value model
  Entity–attribute–value model is a data model to describe entities where the number of attributes that can be used to describe them is potentially vast, but the number that will actually apply to a given entity is relatively modest. In mathematics, this model is known as a sparse matrix...
  
  
• Joint distribution
  Joint distribution
  In the study of probability, given two random variables X and Y that are defined on the same probability space, the joint distribution for X and Y defines the probability of events defined in terms of both X and Y...
  
  
• Knowledge representation
  Knowledge representation
  Knowledge representation is an area of artificial intelligence research aimed at representing knowledge in symbols to facilitate inferencing from those knowledge elements, creating new elements of knowledge...
  
  
• Optimal classification
• Rough set
  Rough set
  In computer science, a rough set, first described by a Polish computer scientist Zdzisław I. Pawlak, is a formal approximation of a crisp set in terms of a pair of sets which give the lower and the upper approximation of the original set...
  
  
• Triplestore
  Triplestore
  A triplestore is a purpose-built database for the storage and retrieval of Resource Description Framework metadata.Much like a relational database, one stores information in a triplestore and retrieves it via a query language...