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· intermediate

A/B Testing and Experimentation

How to run a test whose answer means something. What you are actually assuming, why stopping early breaks it, how big the sample has to be before you start, and what a p-value does and does not tell you.

Pathaxis · Original content

Written in house, from the work rather than from a syllabus. Every example is one we would use ourselves, and every quiz question explains why its answer is right.

85 min 6 lessons 15 quiz questionsStart course

What you’ll learn

  • State a hypothesis and the metric that would settle it, before collecting data
  • Explain what randomisation buys and what it cannot fix
  • Work out the sample size a test needs from the effect worth detecting
  • Read a p-value and a confidence interval for what each actually claims
  • Recognise peeking and multiple comparisons, and why both inflate false positives
  • Separate a statistically detectable effect from one worth acting on

Before you start

  • · Comfort with averages, percentages and a little probability
  • · No prior experiment design

Syllabus

02

How big, how long

Effect size, power and sample size.