Experimental Design

Question 1

Question Types

Answer 1

Difference - are the scores from one group different from another group?(between-subjects) are the scores from condition 1 different to condition 2?(within-subjects)
Relationship - When score in one variable increases does the score for the other variable increase/decrease?

Question 2

Variables

Answer 2

Independent variable- make changes in this variable, actively changing/manipulating (can also be pre-defined variable we can’t change eg age)
Dependent variable - measuring the changes in this variable- want to observe effect/change
confounding variables - how do we know changes in DV are caused by the IV?
-keep all other variables v similar
-controls for variables we can’t change eg. family history
-spread influence of confounding variables across all groups eg ages

Question 3

Predicting results (hypothesis)

Answer 3

Experimental hypothesis - expected answer to question
null hypothesis - opposite of experimental, stating there will be no difference/relationship

Falsifying the null - by doing this we gain evidence that the experimental hypothesis will be true

Question 4

Allocation of participants

Answer 4

Between subjects = 2 groups of separate people
Withing groups = same group does both conditions
+ less chance of confounds
+less people needed
- order effect
-carry-over effect
Solution = counterbalancing