The classifier is an element that functions to classify packets of information according to their contents.

The classifier operates by recognizing patterns from the string, or arrangement, of information. The patterns consist of clauses, each of which is distinguished by the use of specific identifiers A match between a pattern and the classifier is facilitated by the identifiers.

The need for recognition values means that the classifier imposes rules. This property has been used in some operating systems to build a system where new classifiers and new rules can be generated so as to build new functions into the system.

Several examples of the function of classifiers follow. Programs have been written that utilize classifiers to analyze problems by categorizing historical data. Probabilities of the data with respect to several categories can be generated. This computational behavior has proved very useful in the analysis of genetic and medical biochemical information.

In the future, classifiers will prove useful in expanding a computer's capability as a conduit and analyzer of sensory information. A classifier system may be able to recognize environmental signals and categorize them, even if common signals are separated by a period of days. Such an ability would be useful, for example, in sorting out potential extraterrestrial signals and patterns in emerging language.