Measurement: are you measuring what you think

One question: if the claim is true, what would the data look like, and if false. If you cannot tell them apart, there is no design.

Task: A borrowed scale of unknown fit for my population.

[Before you start, do three things]
1. Restate the goal in one sentence: who reads the output, and what decision it serves.
2. If I have not given you the following, ask me. Do not assume:
   - the construct definition
   - the scale and its source
   - target population
   - reliability evidence
3. Say how you plan to do it (at most 5 steps) and wait for my go-ahead.

[Go through each of these]
- write the operational definition
- compare the original sample with mine
- a pilot test plan
- which items may fail in my sample

[Process]
1. State the question as something falsifiable
2. Name the observation that separates true from false
3. Check whether sample, measurement and control can support it
4. List three things that could overturn it
5. State the scope

[Output]
Question, criterion, method, counter-evidence, scope.

[Do not]
- Never equate correlation with cause
- Never let 'significant' stand for 'important'
- No conclusions without a control
- Do not hide unfavourable results