Question Constellation Sign up for free AQA · GCSE · Biology · Higher
Human reaction-time method improvement
The human body has two coordination systems: the nervous system and the endocrine system. Two students investigated human reaction time. Student A held a metre rule above student B's hand. Student A then released the metre rule and student B caught the rule as quickly as possible. Figure 8 shows the method used.
Suggest two ways to improve the students' method for measuring human reaction time.
Write your answer first. You can study the marking guidance whenever you need it.
Study the marking See what earns credit and compare it with a full-mark answer.
Marking points
- 1 Suggests a consistent ruler starting position or another valid control variable.
- 2 Suggests a more precise scale, such as millimetres.
- 3 Suggests repeats with a mean or anomaly handling.
- 4 Suggests converting distance into reaction time.
- 5 Suggests resting the hand or arm on a table.
Full-mark answer
1. Start the ruler from the same position, with 0 cm level with the top of student B's hand. 2. Repeat the test several times and calculate a mean after excluding anomalies.
Why this answer loses marks
Use a more accurate ruler and tell the catcher to try harder.
More accurate is not a method change, and effort is not controlled; specify the scale, starting position, repeats or hand support.