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Experimental design, data analysis, and statistical tooling for modern teams. No hype, just the math.

StatsTest
Time SeriesJan 29New

Comparing Pre/Post Periods: Difference-in-Differences for Product

How to use difference-in-differences to measure product impact by comparing treatment and control groups across pre and post periods.

StatsTest
Time SeriesJan 29New

Granger Causality: Does Feature Usage Actually Drive Retention?

How to use Granger causality to test whether feature usage predicts retention, and why correlation over time is not causation.

StatsTest
Time SeriesJan 29New

Interrupted Time Series: Measuring Impact Without a Control Group

How to use interrupted time series analysis to measure causal impact of launches, policy changes, and events without a control group.