S2.2.2—Processing and interpreting data
- Syllabus
- First assessment 2025
- Objective
- S2.2.2
- Level
- HL
Process only what the research question needs
Show calculations from raw to processed values, then interpret the appropriate table, chart, diagram or graph. Separate what the representation displays from the physical explanation proposed for the pattern.
| Evidence feature | Defensible interpretation |
|---|---|
| Straight best-fit line through the origin within uncertainty | Consistent with direct proportionality |
| Straight line with non-zero intercept | Linear relationship, but not direct proportionality; investigate an offset |
| Curve or changing gradient | Rate of change varies; a linear model is not supported |
| Area under a power-time graph | Energy transferred, because power multiplied by time has energy units |
| Point far from the pattern | Possible outlier; check procedure, uncertainty and repeats before deciding whether to include it |
Justify inclusion or removal
Do not remove a point merely because it weakens the trend. Keep it unless there is a documented measurement or procedural reason to exclude it; where the cause is uncertain, compare the analysis with and without the point and state how the conclusion changes.
Worked data decision
For diameter readings 0.18,0.20,0.21,0.22,0.26,0.18mm, 0.26mm is visibly separated from the cluster. If a documented reason supports exclusion, the mean of the remaining five is 0.198mm≈0.20mm. Without that justification, report the alternative mean or discuss the point rather than hiding it.
Questions explain how a graph supports PV=K or whether a T–d graph supports direct proportionality.
Explain / Outline
Refer to the expected graph form and intercept, not just the presence of a trend.
Calling a non-origin line direct proportionality or ignoring the fit when deciding whether data support a model.
Record before judging
Keep qualitative observations, labelled quantitative data, units and uncertainty visible.
Test the model
Use the graph shape, intercept, fit, error bars and repeats to decide whether a relationship is supported and whether errors are random or systematic.