✓ Reliability (AO1)

Question 1

Reliability

Answer 1

is a measure of consistency
e.g. measuring a box with a ruler, you should get the same measurement each time

Question 2

2 Types of Reliability

Answer 2

internal
external

Question 3

Internal Reliability

Answer 3

the extent to which a measure is consistent within itself

e.g. score on first half of an OCD test should be the same on the second half

Question 4

External Reliability

Answer 4

the extent to which a measure is consistent from one use to another

e.g. your score on an OCD test should be similar if you do it again a week later

Question 5

2 Ways to Assess Reliability

Answer 5

test-retest reliability
inter-observer reliability

Question 6

Test-Retest Reliability

Answer 6

administering the same test or questionnaire to the same people on different occasions
- if the test is reliable, the results should be the same or very similar + 2 sets of scores should significantly correlate
- must be enough time between tests to ppt doesn’t remember answers

Question 7

Inter-Observer Reliability

Answer 7

ensuring 2+ observers are observing behaviour in a consistent way
- the data collected by the different observers should be the same and significantly correlate
- often involves ensuring observers are using behavioural categories correctly

Question 8

4 Things to Improve Reliability of

Answer 8

questionnaires
interviews
experiments
observations

Question 9

How to improve the reliability of Questionnaires?

Answer 9

use the test-retest method - results should correlate highly
if they don’t, identify the questions that are unreliable + remove, replace or reword them so they are clearer

Question 10

How to improve the reliability of Interviews?

Answer 10

use the same interview each time or ensure each interviewer receives similar training, so questions are clear
use structured interviews where questions are pre-written

Question 11

How to improve the reliability of Experiments?

Answer 11

keeping conditions tightly controlled increases reliability - bc of standardised procedures
control extraneous variables for consistency

Question 12

How to improve the reliability of Observations?

Answer 12

rely on interpretations - can lack objectivity
need to operationalise any behavioural categories accurately to avoid subjective decisions