research methods: experiments

Question 1

what is an experiment?

Answer 1

there is a variable that is being compared across conditions, either directly manipulated or naturally occurring

participants allocated into groups

if the groups think or behave differently then you know it’s the IV that has caused the different result, DV as everything else was kept the same

Question 2

what does it mean to operationalise the variable?

Answer 2

stating clearly how a variable will be manipulated (IV) or measured (DV)

Question 3

what are alternative ways to operationalise a variable?

Answer 3

observe to see the participant behave in a certain way

ask the participant to report how often they behave or think in a certain way

Question 4

what is cause and effect and how can it be established?

Answer 4

if one variable is manipulated and a change is able to be measured, then it’s the manipulated IV that’s caused the change DV

cause and effect can only be established if we know only one variable has changed

Question 5

what variables might be extraneous?

Answer 5

age of participant, gender of participant, intelligence of participant, time test is taken
these could all affect the DV

Question 6

how can extraneous variables be reduced?

Answer 6

they need to be controlled and standardised so that they don’t affect the DV, so that we have validity and know we measured what we intended to measure

must control all EV’s by keeping them the same across conditions of variations of the IV by standardising them

Question 7

what are extraneous variables?

Answer 7

other variables that are controlled so they don’t affect the DV

Question 8

how can we control extraneous variables?

Answer 8

good operationalisation
randomised groups
standardisation
repeated measures
matched pairs

Question 9

what’s a confounding variable?

Answer 9

a variable we couldn’t or didn’t control that reduces the validity of our study, meaning that we may not be measuring what we set out to measure, the IV’s affect on the DV.

IV or CV could’ve caused DV so cause and effect can’t be established. lacks validity

Question 10

what’s a condition?

Answer 10

group of participants exposed to one variation of the IV

Question 11

what’s experimental design?

Answer 11

how we put participants into the conditions

Question 12

what are the types of experimental design used to allocate participants to conditions?

Answer 12

independent measures
repeated measures
matched pairs

Question 13

what is repeated measures?

Answer 13

using all participants in all conditions

Question 14

what’s independent measures?

Answer 14

using different participants in each condition of the IV so that each participant only does one condition of the IV. groups independent of each other

Question 15

what is matched participants design?

Answer 15

participants matched for variables that could affect the results, then each participant only takes part in one condition of the IV

eg split all participants into pairs, try to match each pair for weight, height and amount of excessive they do each week (factors that could affect DV) then randomly assign one from each pair to each condition

Question 16

what is an aim?

Answer 16

the purpose of the research

Question 17

what’s a hypothesis?

Answer 17

a specific, testable prediction of how one variable affects another

Question 18

what’s an alternative/alternate/experimental hypothesis?

Answer 18

it predicts the effect of the IV on the DV

alternate hypotheses are either one (directional) or two tailed (non directional)

Question 19

what’s a two tailed alternate hypothesis?

Answer 19

predicting that the IV will have an effect on the DV

the word ‘difference’ ‘effect’ or ‘impact’ suggests there will be a difference but doesn’t suggest the direction of the difference.
you are unsure of how the IV will affect the DV but know there will be an impact

Question 20

what’s a one tailed alternate hypothesis?

Answer 20

predicting specifically how the IV will affect the DV

Question 21

what’s a null hypothesis?

Answer 21

a prediction that the IV will have no effect on the DV

any result found is due to error or chance

Question 22

when is a null hypothesis rejected?

Answer 22

when scientific evidence proves that it isn’t true. it’s accepted as true until this.

if there’s scientific evidence that disproves the null hypothesis then we can reject it and accept the alternative one

Question 23

three things needed to include in a well written null hypothesis

Answer 23

start with ‘there will be no significant difference’

operationalise IV and DV

always end with ‘any difference found will be due to chance’

Question 24

how do you know if a difference is a significant difference?

Answer 24

when there’s less than 5% probability that the difference is caused by chance.
statistics are used to work out how likely it was that a difference was caused by chance.

Question 25

how is significance written and what does significance allow us to establish?

Answer 25

as a ‘p value’. if p<0.05 the results are significant. we can be confident that the IV caused the DV

Question 26

what is a lab experiment?

Answer 26

experiments conducted in artificial environments lab = any controlled environment where the researcher can keep the conditions the same across all conditions and for all participants still manipulating IV and measuring another DV

Question 27

evaluation of lab experiments

Answer 27

replicate the study control extraneous variables establish cause and effect less ecological validity more demand characteristics

Question 28

what are demand characteristics?

Answer 28

participant trying to work out the purpose of the study and behaving differently

Question 29

what’s experimenter bias?

Answer 29

experimenter accidentally or purposely changes behaviour to get results they want or misinterprets data to get results they want

Question 30

what’s a field experiment?

Answer 30

experiment conducted in participants own real life environment still manipulation of the IV and measuring the DV

Question 31

field experiment evaluation

Answer 31

reduced demand characteristics higher ecological validity difficult to replicate difficult to use sophisticated equipment harder to control variables harder to establish cause and effect chances for experimenter bias

Question 32

what does replication mean?

Answer 32

ability to repeat experiment with same conditions and environment

Question 33

what’s a quasi experiment?

Answer 33

experiment using a naturally occurring IV sometimes can’t randomly allocate participants to groups eg can’t change someone’s gender age etc so we just group them together and allow for natural manipulation of IV

Question 34

quasi experiment evaluation

Answer 34

strengths or weaknesses of field or lab exp as can be carried out in either setting no artificial manipulation of IV needed allows us to look at variables it would be impossible or unethical to manipulate sampling bias is a problem as researcher doesn’t have as much control over manipulation of IV across conditions participants not randomly allocated, meaning some variables can’t be controlled for so might be different across different conditions

Question 35

what’s sampling bias?

Answer 35

when we randomly allocate participants we assume that each group is largely the same

Question 36

evaluation of matched groups design

Answer 36

minimizes the influence of individual differences between groups, leading to more reliable results. can be very challenging to find participants who are perfectly matched on all variables, especially if more than one characteristic is being controlled. Even with careful matching, there will always be some level of variation between the individuals in each pair.

Question 37

evaluation of independent measures design

Answer 37

No order effects: Since participants are only in one condition, they do not get better at a task through practice or worse through fatigue and boredom. Reduced demand characteristics: Participants in one group are less likely to guess the study's aim and change their behavior accordingly because they don't see other conditions. There is a higher risk that the differences between groups are due to pre-existing individual differences between the participants (e.g., age, IQ, motivation) rather than the manipulation of the independent variable.

Question 38

evaluation of repeated measures design

Answer 38

Order effects: Participants can be affected by the order in which they experience the conditions. This can be due to:Practice effects: Performing better on later tasks due to familiarity. Fatigue effects: Performing worse on later tasks due to tiredness. Boredom effects: Performing worse on later tasks due to boredom. Demand characteristics: Participants may guess the study's aim and change their behavior, which lowers internal validity. Controls for participant variables: Because the same participants are in all conditions, individual differences (like intelligence or personality) are controlled for, as they act as their own control group. This increases internal validity.

Question 39

overall strengths and weaknesses of experiments

Answer 39

Experiments allow researchers to manipulate an independent variable to see its effect on a dependent variable, enabling causal inferences to be drawn. Psychology experiments often use small, non-representative samples, which limits the generalizability of findings.

Question 40

what is experimenter effect?

Answer 40

participant changes their behaviour due to the presence of an experimenter

Question 41

how can a exp be or not be valid?

Answer 41

Randomly assign participants to groups to minimize the impact of individual differences between groups. Keep both the participants and the researchers unaware of who is in which group to prevent bias. Select measures that are consistent and produce similar results over time.

Question 42

how can an exp be or not be reliable?

Answer 42

Control extraneous variables: Identify and minimize the impact of other factors that could influence the results. Use standardized procedures: Stick to a consistent procedure for all participants to minimize the chances of human error or bias. A standardized procedure makes it more likely that the results can be replicated exactly.

Question 43

what’s the IV?

Answer 43

The variable that is manipulated, controlled, or varied by the researcher to test its effect on the dependent variable.

Question 44

what’s the DV?

Answer 44

the outcome that is measured and tested in an experiment. It is the variable that is hypothesized to be affected by the manipulation of the independent variable