Lecture 2

Question 1

What 2 characteristics determine the quality of a study?

Answer 1

Reliability and validity

Question 2

What is reliability?

Answer 2

Reliability is the degree to which the same finding will be observed in a replication of the study. It refers to the stability or constancy of a measure.
To increase reliability researches often repeat their experiments or those of others.

Question 3

Ways to test reliability

Answer 3

• test/retest reliability - repetition
• split-half reliability - performance of a first half of a measure should highly correlate with the second half of a measure.
• inter-rater reliability - naturalistic observation, then get someone else to do a naturalistic observation and compare the notes taken and see if they match

Question 4

What is validity?

Answer 4

The validity of a study is the degree to which the study accurately addresses the topic it claims to measure. It tests what it is suppose to test.

Question 5

Ways to test validity

Answer 5

• content/face validity - does my measure seem to be measuring what I think it does
• predictive validity - your score will predict a similar score on other related measures of the same construct
• convergent validity - the idea that your measure can predict data on relatable measures
• discriminant validity - the scores on a measure should look different than score that are meant to measure opposite constructs.

Question 6

Issues in designing an experiment in psychology.

Answer 6

• measurement accuracy - difficult to judge in psychology
• measurement sensitivity - is a measurement sensitive to differences
• range effects - you want to make a measure where scores feel the entire range. One way to ensure you get a range is pilot testing.

Question 7

What is pilot testing?

Answer 7

This is when you create a test then get a small sample to take it. Then go home look at the results and then refine it to get a measure with a range of scores.

Question 8

What are the Goals of psychology research?

Answer 8

1) to describe behaviours - and how they inter-relate. E.g. For the past 7 years, happy people have given the most money to charity.
2) predict behaviours - e.g. Next year, happy people should give more money to charity.
3) determine causation - e.g. Does being happy lead directly to being charitable? Is it just correlational or is it causal?
4) explain cause-effect relationships e.g. Why does happiness lead directly to being charitable?

Question 9

Rules of causality:

Answer 9

1. Cause comes before effect
2. Effect only occurs when cause is present
3. Alternatives ruled out