IB Physics IA Guidelines: The Conclusion

Overview of the Conclusion Criterion

The Conclusion criterion is worth a maximum of 6 marks, which accounts for 25% of your total Internal Assessment (IA) grade. It evaluates how successfully you answer your research question by drawing on your data analysis and comparing it to accepted scientific context.

1. Addressing the Research Question and Trends

Your conclusion must directly address the research question and be fully consistent with the data you have presented.

Trend Analysis: Explain the trend line using correct mathematical terminology. Identify if the relationship is "linear" (state positive or negative gradients), "directly proportional", "inversely proportional", or "exponential". Mention features like minima, maxima, or intercepts.
Avoid Bias: Ensure your conclusion is genuinely supported by the data. If your data is inconclusive, lacks clear patterns, or only partially supports a hypothesis, you must state this clearly rather than forcing a "perfect" conclusion.

2. Justifying with Uncertainties and Errors

A conclusion that is "fully consistent" requires the interpretation of processed data including its associated uncertainties.

Final Values: Do not just state a single number. Express your resulting value alongside an experimentally acceptable range based on your measures of variation (e.g., standard deviation or range). Example format: (932 ± 15) J kg⁻¹ K⁻¹.
Percentage Comparisons: Stating the percentage difference (compared to literature values) and percentage uncertainty is considered good practice.
Error Impact: Comment on the presence of random and systematic errors shown in your graphs. You must state the direction of any systematic error and discuss how these errors affect your final conclusion.

3. The Scientific Context

To reach the highest mark band (5-6 marks), your conclusion must be justified through relevant comparison to accepted scientific context.

Traceable Literature: Compare your findings with published values, general models, textbooks, or course notes. Ensure all sources are cited with enough detail to be traceable (e.g., include retrieval dates for online sources).
Plausibility: If there is no accepted literature value for your specific system (e.g., the spring constant of a specific rubber band), you must determine and discuss whether your calculated result is physically plausible and reasonable.
Assumptions: Identify the assumptions made when determining your equations or physics models. These can be practical (e.g., projectile motion remaining in a common plane), mathematical (e.g., assuming a parabolic path for a pendulum), or physical (e.g., treating air as an ideal gas).

Top-Band Checklist (5-6 Marks)