Working scientifically
⏱ ~3-min readAceMark Guide
What this topic is really about
Repeating measurements and calculating a mean reduces the effect of random errors, which increases the precision and reliability of the data. It does not automatically improve accuracy (A), as systematic errors in the equipment could still keep the results far from the true value.
Control variables must be kept constant to ensure that any changes in the dependent variable are only caused by the independent variable. What you change is the independent variable (A), while what you measure is the dependent variable (B), not the control variable.
See the mechanism
Control variables must be kept constant to ensure that any changes in the dependent variable are only caused by the independent variable. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
A control variable in an experiment is:
- Identify what the question tests: A control variable in an experiment is:.
- Control variables must be kept constant to ensure that any changes in the dependent variable are only caused by the independent variable.
- What you change is the independent variable (A), while what you measure is the dependent variable (B), not the control variable.
Traps the examiner sets
- What you change is the independent variable (A), while what you measure is the dependent variable (B), not the control variable.
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Working scientifically and see it stick.
Practice more of this topic →