Understand how we can test and improve validity of a study

The Pros and Cons of different sampling techniques

Definitions

• Internal – Are we really measuring what we want to

• Popluation – Can we apply our findings to other populations other than our sample

• Ecological – Does it reflect real life

• External – Does the task reflect real life?

• Confounding Variables – uncontrolled Extraneous variables

• Extraneous Variables – extra variables that can be controlled

• Demand Characteristics – when a pps guesses the aim of the study and behaves in a way they think is expected

• Experimenter Bias – when a psychologist designs their method or observation in a way that biases their results towards their hypothesis

Definitions

IV DV

Confounding variable

Extraneous Variables

ALL these things affect

VALIDITY!!

Improving External Validity- Repeat the experiment in different ways

Context Validity/Ecological Validity• Also applies across different contexts

Temporal/Historical Validity• Do findings from the past still apply?

Population Validity• Can we apply our findings to other

populations (not just our sample)

Improving Internal Validity30 word wonder!

•Face validity

•Content Validity

•Concurrent Validity

•Predictive Validity

Write it on the board!