Two days of baseline measurement before any environmental…
Run baseline measurements for two days before implementing environmental changes to establish a reference point that accounts for normal daily variation.
When This Fires
- Before any environmental experiment (Five-step environmental experiment's step 1)
- When you're about to implement a workspace change and want to know if it actually helped
- When Collect at least 5 measurements before improving…'s five-measurement principle applies to environmental experiments
- Complements Five-step environmental experiment (experimental protocol) with the specific baseline duration requirement
Common Failure Mode
No-baseline experimentation: "I switched to a standing desk today and I feel more focused!" Without knowing yesterday's focus level under the same conditions, this observation is meaningless — maybe you always feel focused on Tuesdays, or maybe you slept better last night, or maybe the novelty of the new desk is temporarily exciting.
The Protocol
(1) Before making any environmental change, measure your key metrics for 2 consecutive days under current conditions. (2) Use Measure at predetermined fixed times, not end-of-day…'s fixed-time measurement and Rate subjective state on 1-5 or 0-10 scales at 3 fixed…'s scales. Record at the same times on both baseline days. (3) Calculate your baseline range: the lowest and highest scores across both days. This is your "normal." (4) After implementing the change, compare experimental measurements against the baseline range: scores consistently above the range → real improvement. Scores within the range → no detectable effect. Scores below the range → the change may be harmful. (5) The 2-day baseline is a minimum. For higher confidence, extend to 3-4 baseline days, which better captures weekly variation.