Practical articles on statistics, A/B testing and data-driven decisions for product managers and marketers.
10 min read
Peeking in A/B testing turned a 5% false-positive rate into 27.6% in 100,000 simulated tests. When to stop an A/B test, and how sequential testing helps.
10 min read
The Bonferroni correction on a four-variant A/B/n test: why multiple comparisons create false winners, how Holm compares, and what it costs in traffic.
13 min read
Leading questions with examples and neutral rewrites, plus four other false positives that make weak ideas look validated in customer interviews.
9 min read
User interview questions for PMs and marketers: 20 questions to ask customers, grouped by purpose, a bad-vs-better table and a short prep checklist.
12 min read
What is Git, in plain words for product managers: what it does, Git vs GitHub, the basic terms, and how to check what shipped, when and why.
10 min read
Git flow and GitHub flow in plain words: how each Git branching strategy works, when each fits, how gitflow compares to trunk-based, and what PMs need to know.
9 min read
How long to run an A/B test: divide the required sample by eligible daily traffic, round up to whole weeks, and plan for novelty effects and sales.
10 min read
A code review checklist for product managers: how to review a pull request without reading code, what to leave to engineers, and when to approve.
9 min read
What minimum detectable effect (MDE) means, relative vs absolute, and how to set it from business value and your traffic. With a worked example.
9 min read
Outcome vs output in product management: what each one means, where impact fits, and how to rewrite feature roadmap items as measurable outcomes.
9 min read
Semantic versioning (SemVer) explained for PMs: what major, minor and patch mean, tags and GitHub releases, and why merged and live are different moments.
6 min read
TAM SAM SOM in plain words: the three layers of market size, how to calculate each with a worked example, and when the acronym actually helps.
