research methods: reliability

Question 1

What is reliability?

Answer 1

A measure of consistency

Question 2

When can a measurement be considered reliable?

Answer 2

When a particular measurement is repeated and the same result is obtained then that measurement is being described as reliable

Question 3

What measurement tools do psychologists use to collect data from participants?

Answer 3

• questionnaires and interviews
• experimental conditions
• observations

Question 4

What is external reliability?

Answer 4

The extent to which a measure is consistent when repeated

Question 5

What is internal reliability?

Answer 5

The extent to which different parts of a measure are consistent with itself

Question 6

What are two ways reliability can be assessed?

Answer 6

• Test-retest
• Inter-observer

Question 7

What is test-retest reliability?

Answer 7

• Administering the same test or questionnaire to the same person on different occasions
• if the test/questionnaire is reliable, the results should be the same (or very similar) each time it’s administered

Question 8

What is inter-observer reliability?

Answer 8

Two (or more) observers record behaviours during the same observation and compare their data to check that they’re applying the behavioural categories in the same way

Question 9

What should observers ensure they do?

Answer 9

Record data independently

Question 10

How is inter-reliability measured?

Answer 10

Using a correlation coefficient

Question 11

What should the correlation coefficient be for it to be reliable?

Answer 11

It should exceed +0.80

Question 12

How can reliability be improved in questionnaires?

Answer 12

• Reliability should be measured with the test-retest method
• Open questions which could be misinterpreted could be replaced with closed questions that are less ambiguous

Question 13

How can reliability be improved in interviews?

Answer 13

• Use structured interviews rather than unstructured interviews by using a script to ensure each participant has a similar experience
• the best method is to use the same interviewer each time and if it is not possible, the interviewers must be trained e.g. not using leading or ambiguous questions

Question 14

How can reliability be improved in experiments?

Answer 14

• Use standardised procedures for each participant
• lab experiments are more reliable because of the strict controls over the procedure e.g. standardised instructions, the conditions etc

Question 15

How can reliability be improved in observations?

Answer 15

• Behavioural categories should be measurable e.g. ‘pushing’ is clearer to identify than ‘aggression’
• improving the training given to observers can improve their accuracy in assigning a particular observed behaviour to the correct behavioural category
• Pilot studies can identify poorly defined behavioural categories
• operationalisation is the process of clearly defining a behavioural category