Reaction time
Method overview
Participant rests forearm and places fingers at the zero mark. Release the ruler without warning; record catch distance. Repeat, calculate mean and convert distance to reaction time using a table or equation. Compare controlled conditions ethically.
Apparatus set-up
Diagrammetre ruler; chair/table; calculator; optional caffeine condition
Independent variable
condition such as caffeine, distraction or practice
Dependent variable
ruler distance fallen converted to reaction time
Control variables
same participant where possible; same hand; ruler position; warning; environment; trial spacing
Apparatus
metre ruler; chair/table; calculator; optional caffeine condition
Safety
Keep the area clear; avoid unsafe doses of caffeine; obtain consent and allow withdrawal.
Scientific rationale
No warning prevents anticipation; repeats reduce random error; random order reduces practice/fatigue bias.