Multivariate analysis refers to statistical techniques that simultaneously look at three or more variables in relation to the subject under investigation with the aim of identifying or clarifying the relationships between them. The real world is always multivariate. Anything happening is the result of many different inputs and influences. Multivariate analysis can be complicated by the desire to include physics-based analysis to calculate the effects of variables for a hierarchical "system-of-systems". Often, studies that wish to use multivariate analysis are stalled by the dimensionality of the problem.

Multivariate Analysis of Variance (MANOVA) MANOVA is a powerful multivariate test that allows researchers to understand the effect of one or more independent variables on multiple dependent variables. seminal contributions to the analysis of time series data (i.e. Granger (1969)).1 Today, Morgenstern would most likely write a somewhat different monograph. For example, he would likely examine preliminary data with many of the time series techniques and tools which Clive and many of his collaborators have developed over the last four decades.