Week 3: Experimental Designs & Controls

Question 1

Experimental research designs

Answer 1

Aims to establish cause & effect relationships between IV and DV via manipulation & control.

Relies on randomisation of participants into test conditions.

Question 2

Quasi-experimental research design

Answer 2

The same as an experimental research designs by aiming to establish cause and effect relationship between IV and DV.

Key difference: participants are assigned into groups based on non-random criteria.

Question 3

Non-experimental research design

Answer 3

Aims to establish a relationship without inferring cause & effect.

Question 4

Naturalistic observation

Answer 4

A non-experimental research method where behaviour is observed and recorded in real-world settings.

Question 5

Case Studies

Answer 5

And intensive study of an individual subject.

Question 6

Survey research

Answer 6

A non-experimental research design which primarily uses surveys as its method for collecting data.

Question 7

Evaluation research

Answer 7

A non-experimental research design which examines the effects of intervention (policy or practice)

Question 8

Internal validity

Answer 8

how strongly can we assert that changes in our DV are down to our IV and not extraneous variables

Question 9

External Validity

Answer 9

how generalisable are our findings - can we relate findings in sample back to population

Question 10

Experimental manipulation of the IV

Answer 10

experimenter determines which level of the IV a participant is tested at

Question 11

Individual difference manipulation

Answer 11

a characteristic of the participant determines the level of the IV at which they are tested

Question 12

Repeated measures experimental design

Answer 12

each participant is tested at each level of the IV

Question 13

Between groups experimental research design

Answer 13

each participant is only tested at one level of the IV

Question 14

Mixed experimental research design

Answer 14

more than one IV with at least one IV manipulated between groups and at least one within groups

Question 15

Factorial research design

Answer 15

Used to manipulate more than one IV at the same time.
Measures the interaction effects between IVs.
Split into main effects and interaction effects.
May include both repeated measures & between groups designs.

Question 16

Separation

Answer 16

maximise the variation between groups/levels of the IV

Question 17

Compression

Answer 17

minimise the variation within groups/levels of the IV

Question 18

Self-assignment

Answer 18

Participants assign themselves

Question 19

Experimenter assignment

Answer 19

Experimenter assigns participants to conditions

Question 20

Arbitrary assignment

Answer 20

Participant selection based on seemingly non-relevant criteria.

Potential for bias & confounding variables.

Question 21

Random assignment

Answer 21

No criteria for selection
Every member equal chance of being assigned to any group
Ensures groups are equal
Eliminates systematic differences between groups
Randomly distributes extraneous variables over groups

Question 22

Matching assignment

Answer 22

matches participants to treatment groups on specific variables

Question 23

Individual/Precision Matching assignment

Answer 23

pair participants who have identical scores on matching variables

Question 24

Practice effect

Answer 24

An order effect problem where participants becomes better at task due to prior exposure.

Overcome by counterbalancing.

Question 25

Fatigue effect

Answer 25

An order effect problem where participants may become worse as task due to prior exposure. Overcome by counterbalancing.

Question 26

Counterbalancing

Answer 26

Used to overcome order effects when using a repeated measures design. Participant sample is divided in half. One half completes two conditions in order and the other half completing the conditions in reverse order.

Question 27

Intra-subject counterbalancing

Answer 27

All participant to all conditions multiple times and in different orders.

Question 28

Simple Carry Over Effect

Answer 28

when performance on the DV in one condition is contaminated by the effects of the previous condition

Question 29

Differential carryover effects

Answer 29

where carryover effects of one condition of the IV differ depending on the order in which the conditions are completed

Question 30

Maturation (internal development)

Answer 30

A repeated measure design issue. | Changes due to natural development and expected improvement over time.

Question 31

History (external events)

Answer 31

A repeated measure design issue. | External events which affect the participants during the study.

Question 32

Statistical regression

Answer 32

An issue with repeated measure designs. Refers to the tendency to move up or down towards the mean over time. E.g. someone scoring below or above par on a measure - potentially likely to move towards the mean of that variables over repeated measurements

Question 33

Mortality

Answer 33

An issue with repeated measure designs. | Refers to participants leaving the study before it has run for its intended duration.

Question 34

Measurement issues & how to control for them

Answer 34

Refers to problems with equipment or errors in manual recording of data. Controlled by training researchers, multiple data recorders, or observed participant data entry.

Question 35

Attribute effect and how to control for it

Answer 35

Refers to participants responding differently to different experimenters. Controlled by using the same experimenters in all treatment conditions or standardising how experimenter interacts (e.g. script).

Question 36

Rosenthal effect vs Golem effect

Answer 36

Rosenthal effect: participants expected to respond MOST favourably to study are treated differently Golem effect: participants expected to respond LEAST favourably to study are treated differently Controlled for by: double blind, partial blind, or automation

Question 37

Demand Characteristics

Answer 37

Refers to how participants knowledge of the aims of study will cause them to perform in ways that conform to the study's expectations. Controlled for with: single-blind, double-blind, & deception

Question 38

Social desirability

Answer 38

Refers to participant performing in ways that paint them in the best possible light, or the experimenter will find most pleasing. controlled by: single-blind, double-blind, & deception

Question 39

Hawthorn effect

Answer 39

Refers to participant performing better for the attention received for being in a study and not as a function of the nature of the manipulations of the IV. Controlled by: single-blind, double-blind, & deception

Question 40

single-blind

Answer 40

participant is not made aware of true purpose of study

Question 41

double-blind

Answer 41

neither experimenter and participant aware of treatment condition

Question 42

Deception

Answer 42

omission of or altering the truth of information given to the participant during a research study

Question 43

Situational effects

Answer 43

refers to environmental effects on study e.g time of day, weather conditions