Science
Plan a fair test: variables, method and results
Plan a science investigation by deciding what to change, what to measure and what to keep the same. A worked ball-bounce plan models variables, equipment, method and repeat readings, while the pupil page offers a pendulum, dissolving and original-question option.
Plan the bounce test around what changes and what stays the same. Use the teacher’s safety rules.
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Plan a science investigation by deciding what to change, what to measure and what to keep the same. A worked ball-bounce plan models variables, equipment, method and repeat readings, while the pupil page offers a pendulum, dissolving and original-question option.
Complete resource. Use the preview for diagrams and layout.
Page 1
SCIENCE AGES 11 TO 14 FAIR TESTS Planning a fair test Read the model plan first, then plan your own on page 2. NAME CLASS DATE LEARNING GOAL Plan a fair test by saying what I change, what I measure and what I keep the same. SUCCESS CRITERIA I can name the three kinds of variable. I can write a method someone else could follow. I can say how I will stay safe. SO E N T R Y 1 QUESTION Model Does the height a ball is dropped from change how high it bounces? PREDICTION I think the higher the drop, the higher the bounce, because the ball has more energy to start with. E N T R Y 2 Variables Word and shape keys INDEPENDENT VARIABLE I change it DEPENDENT VARIABLE I measure it CONTROL VARIABLES I keep them the same drop height (cm) CM bounce height (cm) READING same ball same floor same way of measuring same person reading the ruler 20 E N T R Y 3 Method E N T R Y 4 Equipment Hold the ball with its bottom at 20 cm. 1 Drop it and watch the bounce against the rule. 2 Record the bounce height. 3 Repeat three times. 4 Change the drop height to 40, 60, 80 and 100 cm and repeat. 5 SET-UP BALL METRE RULE FLAT FLOOR WALL OR STAND TO HOLD THE RULE SAFETY Follow your teacher’s safety rules. Stand with the rule on the floor and never climb on chairs or tables to drop the ball from high. Keep the floor clear. Tell your teacher if anything breaks. E N T R Y 5 Results table Fill in during the test DROP HEIGHT (CM) 20 40 60 80 100 Bounce 1 (cm) Bounce 2 (cm) Bounce 3 (cm) Mean bounce (cm) Investigation planning and variables Page 1 of 2
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SCIENCE AGES 11 TO 14 YOUR PLAN My own fair test NAME CLASS DATE E N T R Y 1 My question: tick A, B or C in the help card, or write my own My prediction: I think ... because ... E N T R Y 2 Variables INDEPENDENT VARIABLE I change it DEPENDENT VARIABLE I measure it CONTROL VARIABLES I keep them the same E N T R Y 3 Is it a fair test? I change only one thing. I measure one thing. I keep everything else the same. I repeat my measurements. VARIABLES HELP CARD A Does the length of a pendulum change the time for 10 swings? Independent length of string Dependent time for 10 swings (seconds) Control same mass on the string, same small release angle, same stopwatch B Does the temperature of water change how fast sugar dissolves? Independent water temperature Dependent time to dissolve Control same amount of sugar, same amount of water, same stirring Safety use warm tap water, never boiling C My own safe question. Ask my teacher first. E N T R Y 4 Method 1 2 3 4 5 6 7 8 E N T R Y 5 Results table I CHANGE 1 2 3 MEAN Equipment I need How I will stay safe Investigation planning and variables Page 2 of 2
A teaching sequence
Plan a fair test with a clear question, variables, repeatable method and appropriate safety steps.
Plan the bounce test around what changes and what stays the same. Use the teacher’s safety rules.
Read the complete materialName the three variables
Read the drop-height and bounce-height question. Use the model prediction to identify a relationship and reason, then name the independent, dependent and control variables.
Which measurement changes because you change the drop height?
Plan the bounce test around what changes and what stays the same. Use the teacher’s safety rules.
Read the complete materialRepeat the bounce test
Position the ball at the stated height, drop it, record the bounce and repeat three times. Change the height and repeat with the same ball, floor and method.
Are the ball, floor and way of measuring the same each time?
Choose a safe question
Choose the pendulum or sugar-dissolving prompt, or propose a safe teacher-approved question. For sugar, use warm tap water, not boiling.
What will you change, and what will you measure?
Write a repeatable method
Write a numbered method, list equipment and relevant safety steps, then prepare a three-trial results table and calculate the mean.
Could someone follow your numbered steps and record three trials safely?
Before you teach
Look for the thinking behind an answer, choose the support your class needs and leave room for an independent response.
What to look for
Check that the independent variable is changed deliberately, the dependent variable can answer the question and control variables are meaningful. Look for repeats, a method another person could follow and safety steps matched to the materials. Ask whether the planned measure is precise enough.
Give a little support
Use a variable sorting card and model how to hold conditions constant. Give pupils a method sequence to order before they write. Provide measuring support and a teacher-approved equipment list; allow a drawing or labelled diagram as well as text.
Take the idea further
Ask pupils to explain how repeated trials affect confidence and how they would handle an anomalous result. They can identify a limitation in the model and suggest a more precise measurement method.
Things to keep in mind
A fair test controls selected variables but cannot remove every source of variation. Practical work requires equipment and risk assessment appropriate to the specific class. The model investigations are examples, not universal instructions for every lab.
Keep the idea. Make it yours.
Bring your topic, learning goal and class context to PLAI™, then review what you create.
Ideas to try with your class
Sample teaching perspectives on what to try, what to adapt and what to watch for.
Meet The Creators
Meet the creators whose teaching interests connect with this template. Find an approach to try with your class.
Arjun Nair
I want pupils to interpret practical data, explain what changed and what they measured, and reconsider their first ideas when observations suggest a better question.
Meet the creator
Dr Anjali Menon
I coordinate Science practicals with the lead technician, linking activity-specific preparation and review with shared laboratory time so the department can notice and respond to gaps early.
Meet the creator
Marek Sobczak
I choose Science practice tied to an exact specification point, making the assessed knowledge or method visible and keeping pathway decisions open to evidence and review.
Meet the creator
Quietly Curious
The model fair test asks how drop height affects bounce height, with a ball, flat floor, ruler and repeated drops at five heights. It names independent, dependent and control variables before pupils plan their own question and method.
Thoughtful Pause
The repeatable steps and three trials per height connect variable control to a results table and mean. Safety notes keep the ruler on the floor and prohibit climbing on chairs to create a higher drop.
Organised Pile
Work through the 20 cm example first, then ask pupils to identify what changes and what stays the same. The equipment sketch gives a visual model for the ball, metre rule and safe setup.
Calm Table
The example is a model plan, not a universal method for every investigation. Check teacher safety rules and the suitability of the equipment and heights before a class carries out its own test.