Experimental methods/designs

Question 1

experimental method

Answer 1

involves the manipulating of an independent variable to measure the effect of the dependant variable

Question 2

variables

Answer 2

any ‘thing’ that can vary or change within an investigation. typically used to determine causality

Question 3

Independent variable (IV)

Answer 3

an aspect of the experiment that is manipulated by the researcher (or changes naturally) so the effect on the DV can be measured

Question 4

Dependant variable (DV)

Answer 4

the variable that is measured by the researcher

Question 5

extraneous variable (EV)

Answer 5

additional, unwanted variables that might potentially interfere with the IV or DV, and should be removed or controlled

Question 6

confounding variable (CV)

Answer 6

a second unintended IV, which systematically changed with the IV, causing changes in the DV which affects the validity of results

Question 7

demand characteristics

Answer 7

participants will change their natural behaviour in line with their interpretation of the aims of the study

Question 8

Lab experiment

Answer 8

conducted under controlled conditions in which the researcher manipulates the IV, to measure the effect on the DV. often involves an artificial task or situation

Question 9

Field experiment

Answer 9

conducted in natural conditions in which the researcher manipulates the IV, participants typically do not know they are taking part

Question 10

natural experiment

Answer 10

where the researcher doesn’t manipulate the IV and instead examines the effect of a naturally occurring IV on the DV

Question 11

quasi experiment

Answer 11

where the IV is an existing difference between people

Question 12

strengths of a lab experiment

Answer 12

-extraneous variables can be controlled
-ethical due to informed consent and right to withdraw

Question 13

weaknesses of a lab experiment

Answer 13

-situation is often artificial and cannot be generalised to everyday life
-may respond to demand characteristics

Question 14

strengths of a field experiment

Answer 14

-natural, uninfluenced behaviour
-less likely to respond to demand characteristics

Question 15

weaknesses to a field experiment

Answer 15

-extraneous variables cannot be controlled
-ethical issues raised such as lack of consent

Question 16

strengths of a natural experiment

Answer 16

-naturally occurring variables are investigated, so reflective of real life
-opportunity to study situations that may otherwise be impossible to study due to practical reasons

Question 17

weaknesses of a natural experiment

Answer 17

-participants can’t be randomly allocated
-naturally occurring events may be rare, reducing opportunities for research

Question 18

strengths of a quasi experiment

Answer 18

-pre existing variables are investigated
-often in controlled conditions where extraneous variables are removed

Question 19

weaknesses of a quasi experiment

Answer 19

-low control over pre existing variables
-people cannot be randomly allocated

Question 20

experimental design

Answer 20

the way in which participants are used in experiments in relation to the different experimental conditions

Question 21

independent groups

Answer 21

when two separate groups of participants experience two different conditions of the experiment.

Question 22

repeated measures

Answer 22

all participants experience both conditions of the experiment

Question 23

matched pairs design

Answer 23

where participants are paired together on a variable or variables relevant to the experiment

Question 24

strengths of independent groups

Answer 24

-no problems caused by order effects
-less likely to guess aim of study and respond to demand characteristics

Question 25

weaknesses of independent groups

Answer 25

-individual differences present -requires twice as many participants (less economical)

Question 26

strengths of repeated measures

Answer 26

-individual differences won’t affect results -don’t need as many participants (more economical)

Question 27

weaknesses of repeated measures

Answer 27

-problems caused by order effects -more likely to guess aim of study and respond to demand characteristics

Question 28

strengths of matched pairs

Answer 28

-no order effects -no individual differences

Question 29

weaknesses of matched pairs

Answer 29

-expensive -time consuming

Question 30

generalisation

Answer 30

the application of the results from a study, to the wider target population

Question 31

qualitative data

Answer 31

non-numerical, subjective data, expressed in words. it allows researchers to develop an insight into participants opinions, feelings and thoughts.

Question 32

quantitative data

Answer 32

objective, numerical data that can be statistically analysed to reveal trends or patterns

Question 33

reliability

Answer 33

a measure of consistency between participants

Question 34

validity

Answer 34

refers to whether something is true or accurate

Question 35

order effects

Answer 35

where learning or boredom affects the second condition

Question 36

pilot study

Answer 36

a small-scale practice investigation carried out prior to the real investigation to identify potential problems with the design, method or analysis, so that amendments can be made

Question 37

why might a researcher use a pilot study for a questionnaire

Answer 37

if participants where confused by certain questions, they can be re-worded more clearly

Question 38

why might a researcher use a pilot study for an observational study

Answer 38

to see if they have missed out an important category on a behavioural checklist, or if the behavioural categories are not specific enough