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  • Product managers
  • Marketers

Statistics for Product Managers and Marketers

A free statistics course for product managers and marketers: read metrics honestly, run A/B tests you can trust and explain the numbers to your team, on realistic product data.

Free24 lessons~16 h 27 min of learning

A cartoon cat sits next to a laptop with bar charts and an open box of cat food.
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  1. Module 1: Describing data

    Typical values, spread, outliers and charts: how to summarise any product metric honestly.

    A stack of cat food boxes surrounded by bar charts, dots and a small line chart.
    1. 1.1Mean, median and mode: the typical valueMean, median, mode and trimmed mean on real-looking CatChow orders: what each one answers, why one bulk order can fool the average, and how not to average averages.~48 min

      1.1 Mean, median and mode: the typical value

      ~48 min · 11 exercises

    2. 1.2Measures of spread: range, SD and quartilesTwo couriers with the same average delivery time, and why only one keeps the promise: measures of spread from range and variance to standard deviation (calculated step by step), quartiles, IQR and the coefficient of variation.~48 min

      1.2 Measures of spread: range, SD and quartiles

      ~48 min · 11 exercises

    3. 1.3Outliers and skewed data: how to find themWhy product metrics have long tails, how to find outliers with the IQR rule, and what to do with them: fix errors, segment different customers, and never delete whales without thinking.~44 min

      1.3 Outliers and skewed data: how to find them

      ~44 min · 11 exercises

    4. 1.4Types of charts: choosing the right oneThe main types of charts (histograms, box plots, bar, pie, scatter and line charts): which question each one answers, how bin width and axes change the story, and the classic ways charts mislead.~47 min

      1.4 Types of charts: choosing the right one

      ~47 min · 11 exercises

    Module examComplete 4 more lessons to unlock
  2. Module 2: Comparing two groups

    From samples to significance: when a difference between two groups is real and when it's noise.

    Two domes of dots, dark and light blue, balanced on a scale.
    1. 2.1Sample vs population and the normal distributionSample vs population: why we study samples to learn about all users, why the bell-shaped normal distribution shows up everywhere, and how the central limit theorem ties them together.~39 min

      2.1 Sample vs population and the normal distribution

      ~39 min · 11 exercises

    2. 2.2Two-sample t-testThe two-sample t-test (Student's t-test): comparing the means of two groups and deciding whether the gap is bigger than chance.~39 min

      2.2 Two-sample t-test

      ~39 min · 11 exercises

    3. 2.3Mann–Whitney: when data isn't normalA rank-based test for skewed metrics like revenue and session length.~41 min

      2.3 Mann–Whitney: when data isn't normal

      ~41 min · 11 exercises

    4. 2.4p-value and statistical significanceWhat a p-value really says, what it doesn't, how the 0.05 significance level turns it into a decision, and statistical versus practical significance.~39 min

      2.4 p-value and statistical significance

      ~39 min · 11 exercises

    Module examComplete 4 more lessons to unlock
  3. Module 3: A/B testing in practice

    Confidence intervals, power, conversion tests and the pitfalls that break real experiments.

    Two identical web pages, one with a blue button and one with an orange button, and a cursor.
    1. 3.195% confidence intervalsBuilding a 95% confidence interval from its formula and margin of error, so you report a range of plausible values instead of one number.~40 min

      3.1 95% confidence intervals

      ~40 min · 11 exercises

    2. 3.2Power analysis and sample sizeA power analysis tells you how many users an experiment needs to detect the effect you care about.~38 min

      3.2 Power analysis and sample size

      ~38 min · 11 exercises

    3. 3.3Conversion rates and the two-proportion z-testComparing conversion rates between variants with a two-proportion z-test and reading uplift correctly.~44 min

      3.3 Conversion rates and the two-proportion z-test

      ~44 min · 11 exercises

    4. 3.4Pitfalls: peeking, multiple testing, novelty effectThe most common ways real A/B tests go wrong, and how to avoid them.~37 min

      3.4 Pitfalls: peeking, multiple testing, novelty effect

      ~37 min · 11 exercises

    Module examComplete 4 more lessons to unlock
  4. Module 4: Many groups and before/after

    ANOVA, interactions, paired tests and repeated measures for comparing more than two groups or the same users over time.

    Several groups of dots and a before-and-after pair of boxes joined by an arrow.
    1. 4.1One-way ANOVA: comparing many groupsTesting three or more variants at once with a one-way ANOVA, without inflating false positives.~40 min

      4.1 One-way ANOVA: comparing many groups

      ~40 min · 11 exercises

    2. 4.2Two-way ANOVA and interactionsA two-way ANOVA for when two factors act together, e.g. a promo that works on mobile but not on desktop.~39 min

      4.2 Two-way ANOVA and interactions

      ~39 min · 11 exercises

    3. 4.3Paired t-test: before and afterComparing the same users before and after a change with a paired t-test or the Wilcoxon signed-rank test.~40 min

      4.3 Paired t-test: before and after

      ~40 min · 11 exercises

    4. 4.4Repeated measures ANOVATracking the same users across several points in time with a repeated measures ANOVA or the Friedman test.~41 min

      4.4 Repeated measures ANOVA

      ~41 min · 11 exercises

    Module examComplete 4 more lessons to unlock
  5. Module 5: Relationships

    Correlation, causation and regression: how metrics move together and how to predict one from others.

    A scatter of dots with a rising trend arrow, a cat and a coin.
    1. 5.1Correlation coefficient: how two metrics move togetherMeasuring how two metrics move together with the correlation coefficient (Pearson and Spearman), and why that alone proves nothing about cause.~45 min

      5.1 Correlation coefficient: how two metrics move together

      ~45 min · 11 exercises

    2. 5.2Simple linear regressionSimple linear regression: predicting one metric from another with a line of best fit, and checking the fit with R squared.~42 min

      5.2 Simple linear regression

      ~42 min · 11 exercises

    3. 5.3Multiple linear regressionMultiple linear regression: separating the effect of several drivers at once, and the two classic traps, overfitting and multicollinearity.~39 min

      5.3 Multiple linear regression

      ~39 min · 11 exercises

    4. 5.4Logistic regression and classificationLogistic regression for yes/no outcomes such as churn or conversion: odds, the odds ratio, a decision threshold, and how to measure how good the predictions are.~40 min

      5.4 Logistic regression and classification

      ~40 min · 11 exercises

    Module examComplete 4 more lessons to unlock
  6. Module 6: Modelling and segmentation

    Forecasts, clustering users into segments, finding survey drivers, and choosing the right test.

    Dots grouped into three circles and an arrow curving up into the future.
    1. 6.1Models and forecastingWhat a model is, how a simple forecasting model extends a trend, and how to tell whether the forecast is any good.~38 min

      6.1 Models and forecasting

      ~38 min · 11 exercises

    2. 6.2Clustering for customer segmentationCustomer segmentation from the data: letting cluster analysis suggest the segments instead of guessing them.~39 min

      6.2 Clustering for customer segmentation

      ~39 min · 11 exercises

    3. 6.3Factor analysis: surveys and NPS driversFinding the few hidden themes behind many survey questions.~40 min

      6.3 Factor analysis: surveys and NPS drivers

      ~40 min · 11 exercises

    4. 6.4Course recap: choosing the right testA decision guide that ties the whole course together.~40 min

      6.4 Course recap: choosing the right test

      ~40 min · 12 exercises

    Module examComplete 4 more lessons to unlock