Field guide · comparison
Compare like with like before calling it improvement
Before-and-after evidence is strongest when the same room, same scoring definitions, and comparable use conditions are aligned. Two different rooms can still be compared, but that is benchmarking — not proof that one intervention caused the difference.
Field guide · comparison
Compare like with like before calling it improvement
Before-and-after evidence is strongest when the same room, same scoring definitions, and comparable use conditions are aligned. Two different rooms can still be compared, but that is benchmarking — not proof that one intervention caused the difference.
Read it
- 01Identify whether this is the same room over time or two different rooms. The inference is different.
- 02Check that both sides have the same dimensions, score definitions, and known/unknown fields before interpreting a delta.
- 03Read safety, jobs, budget, and the primary friction alongside the headline score so a gain in one dimension does not hide a new problem.
Test it
- 01For a before/after case, repeat the reading under a comparable use condition whenever practical.
- 02Look first for the condition the intervention predicted it would move, then inspect collateral movement.
- 03If the evidence is incomplete, label the comparison provisional instead of filling blanks with assumptions.
What counts as proof
The proof is a traceable delta with comparable inputs and a recorded intervention between them. A visually nicer after image by itself is not causal evidence.
Where this comes from
links reviewed 2026-09-08
Demonstrations are optional learning aids and the standards are the floor under the method. Neither is evidence about your room: Room Lab does not treat a video as proof, and a link never replaces a measured test.
Practise this and continue
Step 7 of 9 · advanced
Try it in a real room. Take a before and after of one change at the same time of day, same light, same viewpoint. Anything else you changed invalidates it.