Chapter 1 · Practice 1 of 4
Start from a written question and the decision it informs
Why it matters
Google's Good Data Analysis guide puts it plainly: data analysis starts with questions, not data or a technique. Writing the question down keeps the work focused and shows early which data you are missing.
A useful question has three parts:
| Part | Example |
|---|---|
| What you will measure | Share of new sign-ups who place an order within 7 days |
| For whom and when | Sign-ups from 1 to 30 September, all countries |
| What decision it informs | Whether to keep the new onboarding email |
Ask the person who requested the analysis what they would do differently for each likely answer. If no answer would change anything, the analysis can probably wait.
Do
- Write the question, population and time range at the top of the notebook
- Agree on what result would change the decision before you look
Avoid
- Opening a dataset and looking for "something interesting" with no question