NCJ Number
95825
Date Published
1983
Length
74 pages
Annotation
This manual introduces the concept of pattern description in time series data and gives guidelines on applying that concept in practice.
Abstract
Time series-pattern description provides concrete and readily understood answers to simple descriptive questions about the general pattern of change over time in a variable. It tells the user, in nonstatistical language, whether the variable generally increased, decreased, or stayed the same during the period in question; whether there was a change in the pattern; and if there was a change, roughly when the change occurred. The pattern description method was developed because criminal justice administrators and policymakers often ask the Illinois Statistical Analysis Center for a simple description of the pattern of change over time in one of the many criminal justice time series-data sets. Conventional methods of time series analysis cannot answer many of these simple descriptive questions. This manual includes detailed instructions for interpreting a pattern description graph and illustrates the instructions with many examples of real criminal justice applications. A separate manual tells the user how to produce pattern description graphs on the Illinois Criminal Justice Information Authority computer system. (Author summary modified)