IB Physics IA Guidelines: The Evaluation Criterion

Overview of the Evaluation Criterion

The Evaluation criterion is worth a maximum of 6 marks, accounting for 25% of your total Internal Assessment (IA) grade. It assesses your ability to identify weaknesses and limitations in your methodology, evaluate their relative impact on your results, and suggest realistic improvements.

1. Identifying Weaknesses and Limitations

To score well, you must clearly understand the difference between weaknesses and limitations, and ensure they are specific to your methodology rather than generic statements.

Weaknesses: These relate to the overall approach and procedural steps of your investigation. Examples include issues with the control of variables, the precision of measurement, or unexpected variation in the data. Do NOT include careless human errors (manipulation skills) or hypothetical events lacking evidence.
Limitations: These refer to how your conclusion is restricted in scope. This could be due to the range of data collected, the physical confines of the system you are testing, or the applicability of the mathematical/physical assumptions made.

2. Evaluating the Relative Impact

It is not enough to simply list errors. For the top mark band (5-6 marks), you must explain the relative impact of specific methodological weaknesses or limitations on your final results.

Qualitative Judgment: Assess whether the identified issues had a minor or major effect on the quality and reliability of your data.
Error Analysis: Discuss how the precision of your instruments affected your data (random uncertainties). If your graphs reveal systematic shifts, state the direction of the systematic error and explicitly relate it back to a methodological weakness or faulty instrument.
Database Investigations: If using a database, evaluate issues regarding the curation of the database itself or challenges with theoretical vs. experimental values, rather than questioning the general validity of the source.
Evidence-Based: Your evaluation must be supported by the data analysis presented earlier in the report. Avoid unsupported speculation like "the temperature might have changed" unless you have evidence that it did and that it affected the results.

3. Suggesting Realistic Improvements

Your suggested improvements must directly address the specific weaknesses and limitations you have identified.

Relevance: Do not list generic improvements. Only suggest changing to a more precise instrument if you specifically identified the current instrument's precision as a limitation.
Feasibility: Improvements must be realistic and feasible to conduct within a standard school laboratory environment or field course.
Avoid Generalities: Never use generic phrases like "take more measurements", "eliminate friction", or "perform in a vacuum" unless you provide specific, practical methods to achieve this that are directly tied to an identified flaw in your original procedure.

Top-Band Checklist (5-6 Marks)