Topics to revise
Balanced Forces P2
Nervous System P2
Biology Required practical - Reaction time
Reaction time Practical
Measure how quickly someone reacts to a ruler being dropped between their fingers. .
Independent: person tested / condition (e.g. had caffeine or not). Lots of variables could be chosen here, drugs, age etc.
Dependent: distance ruler falls before catching.
Control: same ruler, same way of dropping, same hand.
Metre ruler, timer (if using digital method).
Conversion chart - converts distance fallen to reaction time.
Keep start position the same, repeat several times, use large sample size.
Improve accuracy with a digital reaction timer
Improve validity by ensuring all people are similar - age, gender (if not being investigated), dominant hand, tiredness, caffeine etc.
Keep start position the same, repeat several times, use large sample size.
Improve accuracy with a digital reaction timer
Improve validity by ensuring all people are similar - age, gender (if not being investigated), dominant hand, tiredness, caffeine etc.
Description: Dominant hand may be faster
Explain: Practice leads to increased reaction time up to a certain point
Caffeine and stimulants increase reaction time.
Drugs and alcohol slow reaction time.
Hold ruler vertically at 0 mark.
Test subject places fingers at bottom ready to catch in line with ruler.
Drop ruler without warning.
Record distance fallen.
Repeat several times and calculate a mean for each person.
Repeat with multiple people.
Use a conversion chart to calculate reaction time.
Compare conditions/groups.