Practical Data Analysis with JMP®

Detecting Patterns Over Time

For much of this book, we have examined variation across individuals measured simultaneously. This chapter is devoted to variation over time, working with data tables in which columns represent a single variable measured repeatedly and rows represent regularly spaced time intervals. In many instances, time series data exhibit common, predictable patterns that we can use to make forecasts about future time periods. As we move through the chapter, we'll learn several common techniques for summarizing variation over time and for projecting future values.

Typically, we classify patterns in a time series as a combination of the following:

• Trend: Long-term movement upward or downward.

• Cycle: Multi-year oscillations with ...