Internal Assessment Guide
IA Purpose and Assessment Criteria · Choosing a Research Question · Worked Example Investigation Outline · Common Pitfalls and Academic Integrity
IB Chemistry topic guide
Internal Assessment
Internal Assessment is a core part of IB Chemistry. This guide connects the syllabus ideas behind Internal Assessment Guide, shows how they appear in worked problems, and points you to the formulas and full lessons needed for exam revision.
What you will learn
Internal Assessment syllabus outline
The units below follow the structure used in the full Study to Learn course. Use the outline to identify exactly which idea needs attention, then work through the public example before continuing to the complete lesson path.
Free worked preview
IA Purpose and Assessment Criteria
This complete preview comes from the Internal Assessment Guide unit. It introduces the core language, shows the method in context, and gives you a real example of the lesson quality before you create an account.
What Is the IB Chemistry IA?
The Internal Assessment is your opportunity to do real science — to design your own investigation, collect and analyse your own data, and write it up as a formal scientific report. Worth 20% of your final IB Chemistry grade, the IA rewards genuine personal engagement and independent thinking far more than perfect results. After this lesson, you will understand what the IA requires, how it is assessed across four criteria (Research Design, Data Analysis, Conclusion, Evaluation), and where students typically gain or lose marks.
The Internal Assessment is an individual scientific investigation into a testable research question. You design and carry out your own experiment, collect and analyse data, and write a report of 6–12 pages. The IA is worth 20% of your final IB Chemistry grade and gives you the chance to explore a topic you are genuinely interested in.
Timeline Overview
Most schools allocate roughly 10 hours of class time for the IA, spread across planning, data collection, and writing. The investigation is typically conducted over several weeks during the first or second year of the course. Your teacher provides guidance during the planning stage but you must carry out the experiment and write the report independently.
The Four Assessment Criteria
Research Design (6 marks)
Assesses how well you communicate the purpose and planning of your investigation. A strong Research Design includes: a focused, clearly stated research question with identified independent and dependent variables; relevant background chemistry explained in your own words; a well-described methodology that another student could follow; and appropriate consideration of safety and environmental/ethical issues. This criterion also rewards evidence of genuine personal interest and initiative — for example, modifying a standard procedure to test a variable you’re curious about, or choosing a research question connected to a personal interest (e.g. the chemistry of a food you cook, or the effectiveness of different antacids).
Data Analysis (6 marks)
Evaluates how you process and present your raw data: recording data with appropriate precision (e.g. burette readings to ±0.05 cm³); calculating averages and uncertainties correctly; choosing the right type of graph; including error bars where relevant; interpreting what the graph’s gradient, intercept, or shape tells you about the chemical relationship under investigation.
Conclusion (6 marks)
Assesses how well you interpret your results and connect them back to your research question and the wider chemistry. A strong conclusion states a clear, justified answer to the research question, compares the result to accepted literature or theoretical values where relevant (e.g. a known enthalpy of combustion, a textbook rate law), and explains the underlying chemistry rather than just restating what the data shows.
Evaluation (6 marks)
Critical reflection on your investigation. A strong evaluation: identifies specific, genuine limitations in your method or equipment; explains how each limitation affected your results (systematic? random?); and proposes realistic, specific improvements. For chemistry, common errors include: incomplete reactions, side reactions, heat loss to surroundings, impurities in reagents, and parallax errors in reading menisci.
ImportantThe four criteria are assessed independently and each is worth an equal 6 marks (24 total) — doing brilliantly on Data Analysis does not compensate for a weak Evaluation, and vice versa. Every criterion needs deliberate attention. (You may come across an older five-criteria structure — Personal Engagement, Exploration, Analysis, Evaluation, Communication — in some IA guides or older resources; that was the previous syllabus’s structure and is not what your report is marked against under the current syllabus.)
Reviewed by the Study to Learn editorial team · Updated 2026-08-04