Calculate effects
Report percentage-point and relative changes with denominators.
Business and customer analytics · EDITION 1.0.0
Write a practical two-arm experiment readout with clear units, absolute and relative effects, Wilson arm intervals and explicitly limited difference intervals.
By Sanjaay Gowda T S · For product analysts, experimentation beginners and business decision owners.
Runtime and hardware details
Python 3.10 or later and a terminal. The supplied project runs locally and uses the Python standard library.
No model, API key, cloud account or network calls are used by the companion.
Basic spreadsheet arithmetic and familiarity with the topic; Python 3.10+ and a terminal for the optional companion project.
Full setup and scope ↓$2.99USD · one-time purchase
Prepared with AI assistance. Independent human technical, editorial and assistive-technology reader review remains pending. Automated checks and agent review are not certification.
PDF + EPUB + companion project. Any applicable tax is shown at checkout. Single-reader ebook terms; companion code is MIT licensed.

TRY THE FREE SAMPLE
Read 6 sample pages to explore the introduction, first chapter and teaching approach before you choose the complete edition.
WHAT YOU WILL LEARN
Report percentage-point and relative changes with denominators.
Use arm intervals and explain approximation limits.
Connect the planned decision to data checks and guardrails.
INSIDE THE BOOK
Python 3.10 or later and a terminal. The supplied project runs locally and uses the Python standard library.
No model, API key, cloud account or network calls are used by the companion.
Learning prerequisites: Basic spreadsheet arithmetic and familiarity with the topic; Python 3.10+ and a terminal for the optional companion project.
Prepared with AI assistance. Independent human technical, editorial and assistive-technology reader review is pending.
The included examples are synthetic teaching material. Model access, software subscriptions, hosting, ongoing updates and consulting are not included.
CLEAR EXPECTATIONS
Write a practical two-arm experiment readout with clear units, absolute and relative effects, Wilson arm intervals and explicitly limited difference intervals. The local companion uses fictional teaching fixtures. Project limits: Independent binary observations and fixed analysis are assumed. No sequential, cluster, sample-ratio or multiple-testing adjustment is implemented. Approximate difference interval is withheld when either arm has fewer than 10 successes or failures.
The 10 companion tests passed on the packaged project. The supplied fictional fixture produced its recorded expected JSON output. EPUBCheck reported no errors or warnings; DAISY Ace and PDF/UA automated checks passed. These local teaching checks are not production accuracy claims or certification. Independent human technical, editorial and assistive-technology reader review remains pending.
Complete the secure Lemon Squeezy checkout to access the PDF, EPUB and companion ZIP. Keep your receipt and download access private. This is a one-time purchase of edition 1.0.0; ongoing updates and consulting are not included.
The full ebook is licensed to one reader. The labelled free sample may be shared unchanged. The companion project is MIT licensed and may be adapted or shared with its licence notice. See the exact ebook terms.
One book. A complete learning project. Evidence you can inspect.
AI-assisted · Independent human review pending