Designing Psychological Investigations

Question 1

Random sampling

Answer 1

Everyone in the target population has an equal chance of being selected
High population validity
Even if it’s random it may not be truly representative of the population
Practical limitations
Sample may not be random as ps may choose not to take part

Question 2

Opportunity sampling

Answer 2

Selected by using people who are most readily available
High chance of biased because sample is chosen from small part of the target population
Leading to low population validity

Question 3

Volunteer sampling

Answer 3

A sample where the participants self select - they volunteer to take part in the research
A particular type of person is likely to volunteer for research
High bias so cannot generalise to target population leading to low population validity

Question 4

Reliability

Answer 4

This refers to the consistency of a particular measurement.

Researchers should be able to measure something time after time and get similar results

Question 5

Replicability

Answer 5

The ability to repeat a study

Question 6

External reliability

Answer 6

This is the ability to produce the same results every time

Question 7

Assessing external reliability

Answer 7

Can be checked using the test - retest method. This is where the test or questionnaire is used twice on the same participants. To get a measure of reliability correlate the two scores, the higher the correlation the more reliable the test/questionnaire

Question 8

Inter-rater reliability

Answer 8

Concerns whether two interviewers or observers can produce the same outcome and are consistent.

Question 9

Assessing inter-rater reliability

Answer 9

Can be assessed by correlating the scores of the two observers to give an indication of reliability. The higher the correlation the the more reliable the observations

Question 10

Internal reliability

Answer 10

This is concerned with the level of consistency within a test or observation

Question 11

Assessing internal reliability

Answer 11

The split half method assesses the extent to which all parts of the test or questionnaire contribute equally to what is being measured. Score on half the items are correlated with scores on the other half. The higher the correlation the more reliable the yet or questionnaire. The reliability of a test could be improved through this method

Question 12

Improving reliability

Answer 12

Taking more than one measurement from a participant and then taking an average score.
A pilot study could be done.
Essential that all of the conditions are the same otherwise any change in results could be due to a change in conditions.
Standardised procedures to allow precise replication.
Standardised behaviour checklist or coding system where the categories of behaviour are clearly defined

Question 13

Validity

Answer 13

Validity refers to whether the test or measure is measuring what is claims to measure.

Question 14

Internal validity

Answer 14

The ability of the study to test the hypothesis that is was designed to test, essentially does the dv measure what it was intended to measure

Question 15

Potential problem for internal validity - experimental designs and controls

Answer 15

If a repeated measures design is used there is danger of order effects such as practice effects. If an independent groups design is used then participants variables are introduced
Controls > order effects can be overcome by counterbalancing the conditions. Participant variables can be overcome by using match pairs design

Question 16

Potential problems for internal validity - poor operationalisation of the variables and controls

Answer 16

Many psychological variables are abstract and it is possible to choose an inappropriate method of measuring them
Controls> clearly defining all research variables or use measures and scales that have been validated in previous studies

Question 17

Potential problem for internal validity - extraneous variables and controls

Answer 17

If there are extraneous variables it is impossible to know whether the iv or the extraneous variable caused the changes in the dv
Controls > all variables except the iv should be kept constant. Standardised procedures also help with control. These are specific procedures which are followed every time the test is carried out this ensures all researchers will test all participants in exactly the same way

Question 18

Potential problem for internal validity - demand characteristic/ evaluation apprehension/ social desirability bias and controls

Answer 18

Demand characteristics - cues that lead the tendency for participants to behave in the way they think is required of them
Evaluation apprehension - ps change their behaviour because they’re anxious about being observed and judged
Social desirability bias - pa want to present themselves in a favourable light
Controls > the single blind technique could be used in which ps do not know what group or condition they are in. Therefore participants cannot change their responses to suit the researchers

Question 19

Potential problem for internal validity - experimenter bias and controls

Answer 19

This is the tendency of experimenters to find what they expect or want to show
Controls- the double blind technique removes both demand characteristics and experimenter bias. In this case neither the participants or the experimenter know what what the condition or group represents

Question 20

Extraneous variables

Answer 20

Any variable other than the iv that may affect the dv - influences both of the conditions

Question 21

Confounding variables

Answer 21

Varies along with the iv so only affects one condition of the iv

Question 22

Assessing validity - concurrent validity

Answer 22

Comparing the results of the test with the results of an existing measure. If the scores agree the questionnaire has a high concurrent validity

Question 23

Assessing validity - content validity

Answer 23

Ask experts in the field to asses the test or questionnaire to see if they are an acceptable measure of the topic

Question 24

Assessing validity - construct validity

Answer 24

Assess how closely the test or questionnaire relates to underlying theoretical constructs

Question 25

External validity

Answer 25

Whether the results of the study can be generalised beyond the study itself

Question 26

Population validity

Answer 26

Having a biased sample can be a threat to external validity

Question 27

Ecological validity

Answer 27

Whether the task itself was artificial and therefore representative and whether findings can be generalised to other settings

Question 28

Why ethical guidelines are important

Answer 28

1 psychological research should aim to improve the quality of life for people
2 professional psychologists are expected to work in an ethical manner

Question 29

Informed consent

Answer 29

Can be gained by using an consent form including :
Objectives of the study
Details about what the participant should have to do
Length of time
Opportunity to ask questions
Right to withdraw
Data will remain confidential

Question 30

Presumptive consent

Answer 30

Where it is assumed consent would be given. Used for a naturalistic observation in a public place people would expect to be observed by others

Question 31

Deception

Answer 31

Deception is only acceptable if there is strong scientific justification for the research and there is no alternative procedure to obtain data

Question 32

Protection from harm

Answer 32

Includes both physical and psychological harm. Risk of harm should be no greater than what is faced in normal life

Question 33

Debriefing

Answer 33

Supposed to return participants to the state they were in when they entered the study.

Question 34

Confidentiality

Answer 34

None of the ps should be identifiable for manny reports that are produced.

Question 35

Privacy

Answer 35

In observational research the privacy of ps need to be respected