Procedural Question: Acing Experiment-Based PSLE Science Questions IV

A Science procedural question requires a pupil to explain in steps on how an experiment should be carried out to achieve the aim of the experiment. Most of the time, pupils will miss out the final step in concluding the aim of the experiment and lose some marks in a Science exam paper. In this article, I will share with you some quick tips on how to tackle a procedural question.

Quick Tips

• Always identify the independent variable and the dependent variable. Remember that all other control variables must be kept the same to ensure a fair test.
• The question usually ends with a phrase like "Describe/explain what should be done ... to conclude..."
• Are the steps you have listed clear enough for another person to try out the experiment? Have you elaborated the steps clearly and sufficiently?
• Does the question require you to conclude? Have you included the step needed to draw a conclusion? Read the question carefully to find out what is required.

Example

Tom had 4 rods made of different materials. All the rods were of the same size. If Tom wanted to design an experiment to find out which of the 4 rods expanded the most, explain how he could carry out the experiment to find out which rod expanded the most?

Step 1: Identify the different type of variables

Independent variable → 4 rods made of different materials.
Dependent variable → Difference in length of rod after heating.
Control variables → Same intensity of heat source, same duration of heating period.

Step 2: Explain the procedure step-by-step

Tom had to heat each rod for 5 minutes (or same duration of time) with the same amount of heat. Measure the length of the rod after it has been heated. Repeat the steps for the other 3 rods.

Step 3: Lastly, conclude on how to find out!

The rod with the greatest difference between the initial length and the final length is the rod which had expanded the most.