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Multivariate: regression, PCA, clustering
An analyst who has never heard of PCA will never ask for it. The model will do it in a minute if you know the word.
Multiple regression: which factors drive an outcome (score from study time, sleep, attendance; sales from ad spend, price, competitor activity) - 'many sliders, which to move and by how much'. PCA: reduce many variables to a few without losing much information (survey questions into themes like product quality or support). Cluster analysis: natural groups the data reveals (Spotify playlists, 'people who bought this also bought', customer segments). With AI, one prompt brings in all three. Excel demo: platform x status x item category in one pivot.
Why it matters
The vocabulary that unlocks the advanced output from every tool that follows.
This idea elsewhereappliedPrompted in Julius