Year 7 Science · Unit 2 · Lesson 19

Working Scientifically — Fair Tests

Foundation Worksheet

Name
Date
Class

Learning Goals

True or False? Fix the false ones

Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.

The dependent variable is what you change in a fair test.

Correct it:

T
F

Repeating trials three times and averaging the results improves the validity of an experiment.

Correct it:

T
F

In a fair test, you should only change ONE variable at a time.

Correct it:

T
F

Controlled variables are things you deliberately change during an experiment.

Correct it:

T
F

An experiment can be reliable but still not valid if you measure the wrong thing consistently.

Correct it:

T
F

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

TermYour answerDefinition
Independent variableA. Getting similar results each time you repeat an experiment
Dependent variableB. The one thing you deliberately change in a fair test
Controlled variableC. A testable prediction written as "If… then… because…"
ReliabilityD. What you measure — the result that depends on the IV
ValidityE. Something kept the same throughout the experiment
HypothesisF. Measuring exactly what you intend to measure; only the IV changes

1. A student investigates whether stirring speed affects how fast sugar dissolves. Name the independent variable and one controlled variable in this experiment.

Recall 2 marks

2. Write a hypothesis for this investigation: "Does the amount of salt affect how quickly it dissolves in water?" Use the "If… then… because…" format.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?