1.1 Two routes to the same assessment objective

Every candidate takes either Paper 3, the Practical Test, or Paper 4, Alternative to Practical. Paper 3 lasts 1 hour 30 minutes and requires candidates to perform experiments. Paper 4 lasts 1 hour and presents experimental situations through diagrams, descriptions and data. Both papers carry 40 marks and contribute 20% of the qualification.

The two papers do not represent different levels of difficulty. They test the same assessment objective, AO3, and assume familiarity with the same experimental contexts. A learner preparing for Alternative to Practical must still understand how apparatus is assembled and used; a learner preparing for the Practical Test must still be able to analyse graphs, evaluate methods and plan investigations in writing.

1.2 The five connected AO3 abilities

Practical competence can be organised into five connected abilities: selecting and safely using apparatus; planning investigations; making and recording observations; interpreting data; and evaluating methods. Examination questions often move through this cycle in one investigation.

For example, a question may first ask for a meter reading, then require a results table, a graph, a gradient, a conclusion and finally an improvement. Treating each part as unrelated makes the paper harder. Instead, keep the physical purpose of the investigation in mind throughout.

1.3 What practical marks reward

Most marks reward specific scientific actions or decisions rather than long prose. A method mark may be earned for stating exactly what is measured, how a variable is changed, what is controlled, how many readings are taken, or how the results are processed.

Vague statements such as ‘do the experiment carefully’ or ‘repeat for accuracy’ are weak because they do not identify an action. Strong answers name the quantity, apparatus and procedure: ‘time 10 oscillations, repeat twice and divide the mean total time by 10’.

1.4 Evidence before conclusion

A conclusion must be justified using observations or data. If a graph is straight and passes through the origin within experimental accuracy, this supports direct proportionality. If two values differ by less than about 10%, they may be considered equal within the expected accuracy at this level.

Do not write a memorised law when the evidence does not support it. Practical questions assess the data actually obtained or shown, even when those data include scatter or an anomaly.

1.5 A practical-answer habit

Use a repeated mental sequence: identify the task; select the quantity and apparatus; state the measurement; include units and precision; process the data; judge the evidence; then evaluate the method. This sequence prevents common omissions.

In Paper 3, read the whole question before changing apparatus because later parts may depend on the original arrangement. In Paper 4, inspect every label, scale and connection before calculating; many errors begin with misreading the diagram.

Worked examples

Practical focus

Examination guidance

Check your understanding

1. How much of the qualification is the practical paper worth?
2. What is the main difference between Paper 3 and Paper 4?
3. Name three AO3 skill groups.
4. Why is “repeat for accuracy” usually too vague?