RM- types of experiment/experimental designs

Question 1

what is the researcher looking for in an experiment?

Answer 1

change in DV due to IV

Question 2

what is the IV?

Answer 2

variable that is manipulated by the researcher

Question 3

what is the DV?

Answer 3

variable that is measured

Question 4

what are extraneous variables?

Answer 4

variable other than the IV which might effect the DV

Question 5

what are confounding variables?

Answer 5

a type of extraneous variable you did not control

Question 6

what does it mean to operationalise a variable?

Answer 6

drawing out the most relevant pieces of information so we can measure them (specifying/simplifying)

Question 7

what is a demand characteristic + how can we reduce them?

Answer 7

• when Pps work out the aim of the experiment and behave how they think the researcher wants them to behave
• if behaviour isnt natural, its a confounding variable which reduces internal validity
  -can reduce by using single blind trial or independent groups

Question 8

what are investigator effects?

Answer 8

when the experimenter has an influence on the results of the research

Question 9

3 examples of investigator effects:

Answer 9

• expectation effects= researcher is deeply committed to a certain outcome, they observe events differently in order to get their outcome
  -presence of the observer= having the researcher present can alter pp behaviour
• age, gender, ethnicity, facial expressions, communication style= may ask a question in an interview or questionnaire which leads the pp to give answers the researcher ‘wants’

Question 10

how to reduce investigator effects

Answer 10

double blind trial= neither researcher or pp know the aims or conditions in the study (also reduces demand characteristics)

Question 11

4 experimental methods/types of experiment:

Answer 11

Laboratory, field, natural, quasi

Question 12

3 features of a lab experiment:

Answer 12

-direct manipulation of IV and measurement of DV
-control= control extraneous/confounding variables, control group could be used without IV manipulation to act as a baseline measurement for comparison, allow cause and effect to be established
-randomisation= randomly allocate pps by flipping a coin or names in a hat, reduces extraneous variables, counterbalancing also uses randomisation

Question 13

laboratory evaluation (2+ 2-)

Answer 13

+easily replicated, high levels of control, checks reliability
+internal validity, easier to control confounding variables, increases ability to establish cause and effect
-reduces ecological validity, artificial, questions accuracy due to inaccurate human behaviour
-demand characteristics, pps know they are being researched, reduces internal validity

Question 14

what does a field experiment consist of?

Answer 14

-natural environment
-researcher manipulates IV and measures DV
-cause and effect can be established, pps are usually unaware of experiment taking place

Question 15

field experiment evaluation (2+ 2-)

Answer 15

+higher levels of ecological validity, natural surroundings for pps, easier to generalise results to situations
+low demand characteristics, pps dont know they are taking part, increases internal validity
-time consuming, researcher cant control amount of pps to enter the area, reduces population validity
-cant control all extraneous variables, natural environment, reduces internal validity

Question 16

what does a natural experiment consist of?

Answer 16

-naturally occurring IV, researcher has no direct control
-natural setting only

Question 17

evaluation of natural experiments (2+ 2-)

Answer 17

+high levels of ecological validity, taken place in natural settings, confident when generalising
+low demand characteristics, pps dont know they are taking part, high internal validity
-likelihood of desired behaviour is limited, researcher has no control if the pps behaviour to the DV is naturally occuring, lacks reliability
-not able to control all extraneous variables due to natural setting, reduces confidence when establishing cause and effect and reduces internal validity

Question 18

whats a quasi experiment?

Answer 18

-pre existing IV (age, gender, phobias etc)
-pps are not randomly allocated
-either lab or natural setting

Question 19

3 experimental designs:

Answer 19

-repeated measures
-matched pairs
-independent groups

Question 20

what are repeated measures?

Answer 20

all pps take part in all IVs

Question 21

what are independent groups?

Answer 21

when pps are split and take turns experiencing each IV, each group is compared

Question 22

what are matched pairs?

Answer 22

when pps are matched into pairs which share the similar characteristics for the experiment, pairs are split into groups, each groups experiences IV

Question 23

repeated measures evaluation (2+ 1-)

Answer 23

+less costly and time consuming (less pps)
+reduces pp variation (easier to compare between IVs)
-order effects (practice effects/fatigue)

Question 24

independent groups evaluation (2+ 2-)

Answer 24

+avoids order effects
+reduces demand characteristics
-pp variation (groups not comparable)
-more pps (expensive, time consuming)

Question 25

matched pairs evaluation (3+ 2-)

Answer 25

+avoids order effects +avoids demand characteristics + reduces pp variations (easier to compare groups) -impossible to match pairs perfectly -more pps required (costly, time consuming)

Question 26

ways to deal with experimental designs limitations:

Answer 26

-counterbalancing (repeated measures) -random allocation (independent groups) -pilot study (matched pairs)

Question 27

repeated measures and matched pairs are related, independent groups are unrelated. what does related mean?

Answer 27

it means that the two groups are easier to compare after the IVs because they are similar/the same groups

Question 28

define randomisation and standardisation

Answer 28

-randomisation= randomly determining the order of experimental conditions/order of IV variables -standardisation= pps in study have the same experience