TThe Diary of a CEO
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Peak Performance

Evidence-to-Change Loop

Replace effort stories with proof, adjustment, and measurable improvement

Difficulty
Easy
Time to result
~weeks to results
Steps
5
Confidence
94%

Metcalfe challenges the loose claim that success comes from hard work alone. His alternative is to ask for evidence: is the product better, is the service better, and are working relationships improving? The loop begins by naming the desired improvement and the facts that would reveal it. Work then produces evidence, not merely activity. If the evidence says the approach is failing, the response is to change it, apply more focused effort, and review again. The mechanism separates persistence from repetition: persistence serves a result, while repetition protects an existing method. Metcalfe applies the same logic to business and personal relationships, arguing that obvious non-performance is a reason to act differently.

Origin

Extracted from The Diary of a CEO

Core principles

  • 01Effort is not the same as progress
  • 02Better results require observable evidence
  • 03A failing approach should trigger a change
  • 04Facts are more useful than reassuring effort stories

How to run it

  1. 1

    Name the desired change

    Define what should become better in the product, service, team, or relationship. Make the target specific enough to inspect.

    Pro tip Describe a visible difference rather than an amount of effort.

  2. 2

    Choose the evidence

    Identify the facts, observations, or behaviours that would show whether improvement is happening.

    Pro tip Use more than one signal when a single number could be gamed.

    Watch out Do not confuse an easy-to-count metric with the whole outcome.

  3. 3

    Inspect honestly

    Review the evidence without using hours worked or good intentions as substitutes for results.

    Pro tip Ask what is better now than at the previous review.

    Watch out A disappointing result does not establish that every part of the approach failed.

  4. 4

    Change what is failing

    When the evidence shows no improvement, alter the method, allocation, or behaviour rather than repeating the same work.

    Pro tip Change one consequential variable you can observe.

    Watch out Do not abandon a sound long-term approach solely because of normal short-term variation.

  5. 5

    Run the loop again

    Apply focused effort, collect fresh evidence, and compare it with the previous state.

    Pro tip Set the next review point before returning to execution.

In the wild

Testing whether work is producing improvement

Metcalfe contrasts people who work very hard with focused builders who ask whether the product, service, and working relationships are actually getting better. Later, he says that when something is not working, the evidence should prompt a change rather than passive acceptance.

Effort is judged by observable improvement and revised when the evidence stays weak.

Common mistakes

Counting effort as evidence

Long hours can coexist with a product, service, or relationship that is not improving.

Repeating an unchanged method

Persistence becomes wasteful when poor evidence never causes the approach to change.

Optimising one misleading number

Evidence should reflect the real outcome rather than reward a convenient proxy.

Is it for you?

Best for

It is best for repeated work where a team can observe changes in quality, behaviour, or outcomes.

Not ideal for

It is not ideal when meaningful results cannot yet be observed or when a single short-term metric would distort a long-term goal.

From the transcript

it's about the evidence it's about can you make change are you getting better

Julian Metcalfe · (25:30)

when things don't work out it's obvious change it

Julian Metcalfe · (1:10:00)

From the episode

Pret & Itsu Founder: How I Built TWO Billion Dollar Brands At The Same Time!: Julian Metcalfe