Trend Analysis

analysis of the general movement or tendency

The term "trend analysis" refers to the concept of collecting information and attempting to spot a pattern, or trend, in the information. In some fields of study, the term "trend analysis" has more formally-defined meanings. Although trend analysis is often used to predict future events, it could be used to estimate uncertain events in the past, such as how many ancient kings probably ruled between two dates, based on data such as the average years which other known kings reigned.
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Noun
1. analysis of changes over time
(hypernym) analysis, analytic thinking

a forecasting method in which likely future sales are estimated by statistical analysis of previous sales patterns.