How to Revise IGCSE Physics Practical Skills

Practical skills are tested in both Paper 4 (Extended Theory) and Paper 6 (Alternative to Practical). Even if you have not performed every experiment in the lab, you can revise the skills systematically.

What is tested

The practical assessment covers:

1. Planning experiments: identifying variables (independent, dependent, controlled), choosing appropriate apparatus, describing a method.
2. Recording data: reading scales, recording to the correct number of significant figures, constructing results tables.
3. Analysing data: calculating averages, plotting graphs, drawing lines of best fit, reading values from graphs.
4. Evaluating experiments: identifying sources of error, suggesting improvements, explaining anomalous results.

How to revise planning

For each required practical, write out:

• What you are measuring (the dependent variable).
• What you are changing (the independent variable).
• What you must keep the same (the control variables).
• What apparatus you would use and why.
• A step-by-step method (at least 5 clear steps).

Practice this for 3 to 4 different experiments. The pattern is similar across all of them. Once you can plan one experiment well, you can plan any.

How to revise data recording

Get blank results tables from past papers. Practice filling them in with realistic data. Pay attention to:

• Column headings include the quantity and the unit (e.g., “Length / cm”).
• Readings are recorded to the correct precision (e.g., a ruler reads to the nearest mm, not the nearest cm).
• Repeated readings are taken and averaged.

How to revise graph skills

Graphs are worth significant marks. Practice:

• Choosing appropriate scales (use at least half the grid in each direction).
• Plotting points accurately (within half a small square).
• Drawing a smooth line of best fit (not connecting dot to dot unless the relationship is linear).
• Reading gradient from the graph (choose two points far apart, show the triangle).
• Identifying anomalous points (circle them but do not include them in the line of best fit).

How to revise evaluation

For each required practical, write down:

• One source of random error and how to reduce it (e.g., take repeat readings).
• One source of systematic error and its effect (e.g., a zero error on a balance shifts all readings by the same amount).
• One improvement to the method (e.g., use a light gate instead of a stopwatch to reduce human reaction time error).

Practice papers

Paper 6 past papers are the best resource. Work through at least 5 full Paper 6 papers, marking each one against the mark scheme. Focus on the wording the mark scheme uses, as practical answers require specific terminology.