You could carry out a number of investigations to determine the effect of a specific factor on human reaction times.
A simple method to measure the effect is to use the ruler drop test.
|1 cm||50 ms|
|5 cm||90 ms|
|10 cm||140 ms|
|15 cm||170 ms|
|20 cm||200 ms|
|25 cm||230 ms|
|30 cm||250 ms|
You could carry out the experiment with and without background noise, or to investigate the effect of a drink containing caffeine on reaction time.
|Attempt||Distance on ruler||Distance on ruler|
|With noise||Without noise|
|1||25 cm||18 cm|
|2||38 cm||15 cm|
|3||36 cm||22 cm|
|4||31 cm||24 cm|
|5||38 cm||13 cm|
What effect does noise have on the speed of reaction, measured in centimetres? [2 marks]
There is a clear difference between length of ruler that passed through the fingers before they managed to catch it, with and without noise. [1 mark]
For example, the first set of data, with noise – an average of 34 cm was obtained, compared with 18 cm without noise. This suggests that noise increases the reaction times of the person in this experiment. [1 mark]
Tip: Calculate an average from all your data, unless there are obvious anomalous results, or outliers. If some pieces of data don't fit the pattern, exclude these from your calculation of the mean.