IA Playbook
Frame your aim, design, and analysis so the investigation reads like one controlled study.
Use this guide to align your aim, theory, sampling, statistics, and evaluation with the IB psychology investigation criteria.
Psychology IA
See what each criterion measures, how many marks it carries, and what stronger evidence usually looks like.
This is Marksy's independently written criteria explanation, not an official IB publication.
How clearly the study's aim, relevant theory or model, and hypotheses are established.
Stronger evidence
The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.
Early-stage evidence
Only fragments of relevant evidence are visible. The response begins to address introduction, but important parts remain missing, unclear, or unsupported.
How appropriately the design, sampling, participants, controls, and procedure are explained.
Stronger evidence
The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.
Early-stage evidence
Only fragments of relevant evidence are visible. The response begins to address exploration, but important parts remain missing, unclear, or unsupported.
How accurately descriptive and inferential results are processed, presented, and interpreted.
Stronger evidence
The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.
Early-stage evidence
Only fragments of relevant evidence are visible. The response begins to address analysis, but important parts remain missing, unclear, or unsupported.
How effectively findings are discussed in relation to theory, method, limitations, and improvements.
Stronger evidence
The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.
Early-stage evidence
Only fragments of relevant evidence are visible. The response begins to address evaluation, but important parts remain missing, unclear, or unsupported.
| Marks | What the draft currently shows |
|---|---|
| 0 | The submitted material does not provide assessable evidence for introduction. |
| 1-2 | Only fragments of relevant evidence are visible. The response begins to address introduction, but important parts remain missing, unclear, or unsupported. |
| 3 | Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained. |
| 4-5 | The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps. |
| 6 | The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly. |
| Marks | What the draft currently shows |
|---|---|
| 0 | The submitted material does not provide assessable evidence for exploration. |
| 1 | Only fragments of relevant evidence are visible. The response begins to address exploration, but important parts remain missing, unclear, or unsupported. |
| 2 | Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained. |
| 3 | The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps. |
| 4 | The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly. |
| Marks | What the draft currently shows |
|---|---|
| 0 | The submitted material does not provide assessable evidence for analysis. |
| 1-2 | Only fragments of relevant evidence are visible. The response begins to address analysis, but important parts remain missing, unclear, or unsupported. |
| 3 | Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained. |
| 4-5 | The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps. |
| 6 | The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly. |
| Marks | What the draft currently shows |
|---|---|
| 0 | The submitted material does not provide assessable evidence for evaluation. |
| 1-2 | Only fragments of relevant evidence are visible. The response begins to address evaluation, but important parts remain missing, unclear, or unsupported. |
| 3 | Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained. |
| 4-5 | The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps. |
| 6 | The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly. |
Did You Know? Most weak drafts fail from sequence chaos, not lack of ideas.
Step 1
Make the theoretical basis, variables, and operationalized hypothesis explicit before moving into the method.
Step 2
Justify the sampling, participants, controls, and materials instead of listing them without context.
Step 3
Choose statistics and graphs that actually answer the hypothesis and make the findings easy to follow.
Step 4
Link each limitation and proposed modification directly to the hypothesis and observed findings.
Did You Know?
Marksy uses independently written criteria guidance to flag missing operational definitions and help you tighten the link between statistics and conclusions. Every criterion mark is an estimate, not an official result. The result includes an estimated mark for every criterion, evidence from your draft, and the changes to make first. Your final mark may differ after teacher assessment or external moderation.
Instant Grading Results
See where your score is now, not just where it could be.
Criterion-By-Criterion Feedback
See the estimated mark, evidence, and next step for every assessment criterion.
Action List To Improve
Get concrete next edits instead of vague "improve analysis" advice.
Confidence And Integrity Signals
Review flagged sections and strengthen authenticity before submission.