ABSTRACT
Time series analysis is a statistical procedure appropriate for repeated observations on a
single subject or unit. It can be viewed as an exemplar of longitudinal methods. A
practical advantage of the procedure is that it is highly appropriate for the type of data
often available in applied settings. A theoretical strength is that the method emphasizes
the nature of the change process and is appropriate for assessing the pattern of change
over time. The goal of the analysis may be to determine the nature of the process that
describes an observed behavior or to evaluate the effects of an intervention. Modern time
series analysis and related research methods represent a sophisticated leap in the ability to
analyze longitudinal data gathered on single subjects.