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IA Playbook

Biology IA Criteria Guide

Design a focused investigation, control variables cleanly, and evaluate with biological precision.

This guide keeps the Biology IA anchored to a clear research question, reliable data collection, uncertainty-aware processing, and a conclusion that is honestly supported by the evidence.

Biology IA

Assessment criteria

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.

Criterion A: Research Design (6 marks)

How clearly the investigation establishes its context, question, variables, and method.

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 research design, but important parts remain missing, unclear, or unsupported.

Criterion B: Data Analysis (6 marks)

How accurately the submission records, processes, displays, and interprets evidence.

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 data analysis, but important parts remain missing, unclear, or unsupported.

Criterion C: Conclusion (6 marks)

How well the conclusion answers the research question using the processed evidence and relevant subject knowledge.

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 conclusion, but important parts remain missing, unclear, or unsupported.

Criterion D: Evaluation (6 marks)

How thoughtfully the submission judges the investigation and proposes realistic 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.

Markband guide

Criterion A: Research Design (6 marks)

MarksWhat the draft currently shows
0The submitted material does not provide assessable evidence for research design.
1-2Only fragments of relevant evidence are visible. The response begins to address research design, but important parts remain missing, unclear, or unsupported.
3Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained.
4-5The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps.
6The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.

Criterion B: Data Analysis (6 marks)

MarksWhat the draft currently shows
0The submitted material does not provide assessable evidence for data analysis.
1-2Only fragments of relevant evidence are visible. The response begins to address data analysis, but important parts remain missing, unclear, or unsupported.
3Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained.
4-5The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps.
6The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.

Criterion C: Conclusion (6 marks)

MarksWhat the draft currently shows
0The submitted material does not provide assessable evidence for conclusion.
1-2Only fragments of relevant evidence are visible. The response begins to address conclusion, but important parts remain missing, unclear, or unsupported.
3Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained.
4-5The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps.
6The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.

Criterion D: Evaluation (6 marks)

MarksWhat the draft currently shows
0The submitted material does not provide assessable evidence for evaluation.
1-2Only fragments of relevant evidence are visible. The response begins to address evaluation, but important parts remain missing, unclear, or unsupported.
3Some relevant evidence is developed, although the response is inconsistent or leaves important connections unexplained.
4-5The response addresses the criterion securely in most places, using relevant evidence and generally clear reasoning, with limited gaps.
6The response addresses the criterion consistently and precisely. Evidence is well selected, reasoning is sustained, and important choices or limitations are handled convincingly.

Build Sequence

Did You Know? Most weak drafts fail from sequence chaos, not lack of ideas.

Step 1

Shape one focused question

Pick a biological relationship that can be measured clearly and kept narrow enough to investigate well.

Step 2

Design for control

Define variables, controls, and repeats so the method is reproducible and the data is worth trusting.

Step 3

Process data with care

Show calculations, graphs, and uncertainty handling clearly so the analysis reads as scientific rather than descriptive.

Step 4

Evaluate against the evidence

Link your conclusion to the data, compare it to biological context, and suggest improvements that directly address weaknesses.

Submission Checklist

  • Research question is specific and testable.
  • Methodology is detailed enough to replicate.
  • Raw and processed data are presented with units and uncertainty where relevant.
  • Conclusion and evaluation are grounded in the evidence, not guesswork.

Quick Wins

  • State the independent, dependent, and controlled variables in one clean planning table.
  • Add uncertainty notes to the data table before writing the analysis.
  • Use one sentence at the end of each paragraph to tie back to the research question.

Did You Know?

Turn Biology Data Into A Higher Band Draft

Marksy gives independently written feedback highlighting gaps in analysis and evaluation. Verify it against current school or authorized source materials before submission. 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.

1. Upload your IA draft PDF to Marksy.
2. Get an estimated mark and feedback for every IA criterion.
3. Revise and resubmit with focused improvements.
Marksy grading results view

Instant Grading Results

See where your score is now, not just where it could be.

Marksy criterion feedback highlights

Criterion-By-Criterion Feedback

See the estimated mark, evidence, and next step for every assessment criterion.

Marksy list of fixes for an IB draft

Action List To Improve

Get concrete next edits instead of vague "improve analysis" advice.

Marksy AI detection and highlight review

Confidence And Integrity Signals

Review flagged sections and strengthen authenticity before submission.

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