Reaction time Pratical

Describe Pratical

1)Get 2 people, person 2 measures the reaction time of person 1

2)Person 1 sits on a stool with good upright posture

3)Person 1 then places forearm of dominant arm across the table with their hand overhanging the edge

4)Person 2 holds a ruler vertically with 0cm mark being between persons 1 thumb and first finger

5)Person 2 then tells person 1 to prepare to catch the ruler

6)Person 2 now drops the ruler at a random time

7)Person 1 has to catch the ruler with their thumb and first finger as quickly as possible when it drops

8)Person 2 now records the measurement on the ruler that is level with the top of person 1s thumb

9)Person 1 should have a short rest.

10)The test is then repeated several times and a mean is calculated

11)We can convert our results into reaction time by using a conversion table on the internet.

12)The two people then switch place with person 1 testing the reaction time of person 2 to allow us to see if the two have different reaction times

What is the independent variable

The person having their reaction time tested

What is the dependent variable

The reaction time

What are the control variables

-The starting distance between thumb and first finger

-Always measure ruler at top of thumb

-Keep conditions of room the same e.g lighting,background noise

What are the different independent variables we can measure

1)Effect of practice-One person catches the ruler a large number of times and then see if reaction time changes depending on number of tries

2)If reaction time depends on the hand catching the ruler-We carry out test with dominant hand and then non-dominant hand with same person

3)If certain chemicals affect reaction time e.g caffeine-Test subject drinks a measured amount of cola half an hour before experiment and then compare this reaction with their normal reaction time.We also have to check that person has no medical issues which might be affected by caffeine like allergy or heart condition. Also make sure test is in a lab where hazardous chemicals are not normally used

What’s the problem with the caffeine test

-There could be other chemicals in cola that affect the reaction time. So to check that we carry out test with caffeine-free cola and compare this reaction time with their normal reaction time.