Career evidence
Context, Action, Impact, Proof: how to write an achievement someone will believe
Quick answer
Write every achievement in four parts. Context: what the situation was and why it mattered. Action: what you personally did. Impact: what changed because of it. Proof: how someone else could check it. If one part is missing, the achievement reads as a claim rather than evidence.
Written by the Look at you go team ยท Published 24 September 2026
Why four parts
Most achievements fail in the same way. They say what happened but not who did it, or who did it but not what changed, or what changed but not how anyone knows. Each of the four parts closes one of those gaps.
The four parts
Context
The situation, the stakes and the constraint. One sentence. Enough for a stranger to understand why this mattered.
Action
What you did, in the first person. Owned, decided, built, negotiated, fixed. Not helped with or was involved in.
Impact
What changed as a result. A number if you have one, a before and after if you do not.
Proof
Where the evidence lives. A report, a dashboard, a message, a named person who saw it. Something that can be checked.
Worked examples
These are illustrations written to show structure. They are not quotes from real people, and the figures are illustrative.
From claim to evidence
Weak
Improved the onboarding process.
Strong
New starters were taking three weeks to ship their first change (Context). I rewrote the setup guide and paired each starter with a buddy (Action). Time to first change fell to eight days across the next five hires (Impact). Tracked in the team onboarding sheet; two starters mentioned it in their probation reviews (Proof).
Weak
Handled a difficult client.
Strong
A client was threatening to leave after two missed deadlines (Context). I took over the account and ran a weekly call with a written plan (Action). They renewed for another year (Impact). Renewal is on record in the CRM; my director was copied on the plan (Proof).
Weak
Worked on cost savings.
Strong
Our software spend had grown without review (Context). I audited every licence and cancelled the unused ones (Action). Annual spend fell by an amount finance confirmed (Impact). Finance signed off the savings in the quarterly report (Proof).
How it differs from STAR
STAR (Situation, Task, Action, Result) is built for answering interview questions out loud. Context, Action, Impact, Proof is built for written evidence that has to stand up on its own months later. The difference is Proof: in a review or promotion case, nobody can ask you a follow-up question, so the evidence has to point to itself.
| Situation | Better fit |
|---|---|
| Answering an interview question | STAR |
| Writing a self-assessment or appraisal | Context, Action, Impact, Proof |
| Building a promotion case | Context, Action, Impact, Proof |
| Writing CV bullet points | Action and Impact, with Proof kept in reserve |
Copy this template
- Context: The situation was ___, which mattered because ___.
- Action: I ___.
- Impact: As a result, ___ changed from ___ to ___.
- Proof: This is recorded in ___ / seen by ___.
Before you use an achievement
- Could someone who was not there understand the context?
- Is the action clearly yours, not the team's?
- Is there a before and after, even without a number?
- Could a sceptical reader check it?
- Is it free of confidential or personal information you should not keep?
Related questions
- What if I do not have a number for Impact?
- Use a before and after instead: what was true before, what is true now. A clear change without a number is still evidence. An invented number is not.
- How long should each achievement be?
- Two to four sentences for a review or promotion case. For a CV, compress it to one line of Action and Impact, and keep the Context and Proof ready for the interview.
- Can I use this for team achievements?
- Yes, but be precise in the Action part about what you did yourself. Reviewers discount team results where the individual contribution is unclear.
Capture all four parts while it is still fresh
Try the 90-second check-inRelated guides
- How to track your accomplishments at work
- What to put in your performance review
- Evidence for a promotion: what actually counts
- Performance review memory test
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