Experimental Method

Question 1

Independent variable

Answer 1

The thing you change

Question 2

Dependent variable

Answer 2

The thing you measure

Question 3

Extraneous variables

Answer 3

Variables that might affect the DV if they are not controlled for

E.g. weather, background noise, temperature

Question 4

Confounding variables

Answer 4

Variables which might affect your DV; they vary systematically with the IV, so they might not affect all participants in the same way

E.g. gender -> depends on the IV

Question 5

Directional (one tailed) hypothesis

Answer 5

States the type of relationship

E.g. there will be an increase …

Question 6

Non-Directional (two tailed) hypothesis

Answer 6

States there will be a relationship but not which way

E.g. there will be a difference…

Question 7

Null hypothesis

Answer 7

Doesn’t predict a change or difference

(IV will NOT affect the DV)

E.g. there will be no significant difference

Question 8

How do we know when to select a directional or non-directional hypothesis?

Answer 8

Directional = based on previous research

Non-directional = no/little precious research/studies are contradicting/no clear direction