1. Psychology Experiments
Field
Lab

2. Hypotheses
Null vs alternate hypotheses
1-tailed
vs
2-tailed

3. Variables
Cause Effect
How can you be sure?

4. Extraneous variables
Participant variables
Situational
variables
Demand
characteristics:
•Single blind
•Double blind

5. 3 basic designs
• Independent measures
– Assign participants at random
• Repeated measures
– Every participant does every condition
• Counterbalance order effects
• Matched pairs
– Each participant matched with another
‘identical’ participant

6. Descriptive statistics
• Mean, median and mode
• Range and standard deviation

7. Descriptive statistics
• Mean, median and mode
• Range and standard deviation