Cognitive Research methods

Question 1

Types of experiments

what is a laboratory experiment and the advanages and disadvantages? (give examples)

Answer 1

• The IV is directly manipulated, all other extraneous variables are controlled and participants are randomly allocated to conditions
• e.g. Milgram, Baddeley

Advantages:
- high controlled confident in control of extraneous variables. So we know that only the IV has affected the DV. Claim a cause and effect relationship

Disadvantages:
- more artificial environment: behaviours observed may be less natural, they are less representative of everyday behaviours

Question 2

Types of experiments

what is a field experiment and the advanages and disadvantages? (give examples)

Answer 2

• The researcher controls the IV but the experimenter cannot control other extraneous variables to the same extent that one can in the laboratory
• participants are not necessarily randomly allocated to conditions
• e.g. sebastian and gill

advantages:
- more natural environment: behaviours more representative of everyday instance of the behaviour, therefore the findings of the study can be applied

disadvantages:
- difficult to control: hard to control all the confounding variables. Therefore, factors other than the IV may have affected the DV. More difficult to conclude changes in DV are due to IV manipulation

Question 3

Independent and dependent variables

what is the independent variable?

Answer 3

the element of the study which is directly manipulated (changed) by the researcher

Question 4

Independent and dependent variables

what is the dependent variable?

Answer 4

the element which is being measured by the experimentor

Question 5

operationalisation of variables

what is the operationalisation of variables?

Answer 5

• this is how we intend to measure or test the variables in a study in a precise way
• variables (such as the IV and DV) need to operationalised in order to be objective and so the study can be replicated
• effective operationalised will ensure high reliability and validity
• your IV should include the names of both of the conditions (groups) you are comparing

Question 6

operationalisation of variables

Experiment one: Metzler et al (2000) compared participants from a STI clinic who received an intervention programme, which raised awareness about safer sex and how to handle difficult sexual situations, to a second group of participants who received the usual care. Metzler found that the participants who received the intervention programme reported fewer sexual partners six months later, than the participants who received the usual care programme.

identify the IV and DV

Answer 6

IV - whether the participants received usual care or intervention programme
DV - number of sexual partners six months later

Question 7

operationalisation of variables

Experiment two: Deci et al (1974) compared the motivation in participants who received performance related pay, and participants who received no payment for carrying out standard workplace tasks.

identify the IV and the DV

Answer 7

IV - whether participants received performance related pay or not
DV - motivation in workplace (how much work completed in a week/questionnaire asking how motivated they feel on a scale of 1-10/work targets or goals for the next week/month)

Question 8

Hypotheses

what is a hypotheses?

Answer 8

• is a prediction
• it is a statement of what you believe to be true or what you believe will happen in an investigation
• must contain the IV and the DV

Question 9

Hypotheses

what is a null hypothesis?

Answer 9

• states that the IV will have no effect on the DV e.g. nothing will happen

Question 10

Hypotheses

what is a experimental hypothesis?

Answer 10

states that the IV will have an effect on the DV

Question 11

Hypotheses

what is a one tailed hypothesis (directional)?

Answer 11

• hypothesis specifically states the direction of the results
• it predicts the nature or direction of the outcome

Question 12

Hypotheses

what is a two-tailed (non-directional)?

Answer 12

• hypothesis does not state the direction of the results
• it could go in either direction - that is it could be ‘more’ or ‘less’

Question 13

Experimental design

what is an independent group design? (e.g. sebastian and hernandez-gill, 2012)

Answer 13

• recruit a group of participants
• divide them into two groups
• one group carries out tasks in condition one, other group carries out tasks in conditions two (could be a a control group)

Question 14

Experimental design

what is a matched-pairs design? (e.g. sherif)

Answer 14

• recruit a group of participants
• find out their demographics and key features (e.g. age, gender, intelligence etc)
• recruit another group of participants that match them one for one
• treat the experiment as independent measures

Question 15

Experimental design

what is a repeated measures design? (e.g. milgram)

Answer 15

• recruit a group of participants
• participants take part in both conditions

Question 16

Potential issues of experimental designs

what are the potential issues for experimental designs?

Answer 16

• order effects - occurs when participants’ reponses in the various conditions are affected by the order of conditions to which they were exposed
• demand characteristics - cues in an experiment that can lead participants to change their behaviour or responses based on what they think they research is about
• participant variables - (individual differences between participants) affecting the results between conditions, rather than solely manipulation of the independent variable
• number of participants required in a sample - matching participants is a more complex process it is difficult to find a large number of participants that match each other identically

Question 17

potential issue management of experimental designs

how do you control the issues faced by each design?

Answer 17

Independent group design:
- crucial that participants are randomly allocated to the different conditions
- differences should be quite small using randomisation

Repeated measures design:
- order effects can be controlled through counterbalancing
- means that the participants go through the conditions in different orders
- there should be an equal number of participants going through each order
- this mean that the order effects are removed, of each group and condition cancels each other out

Matched paird design:
- monozygotic twins (identical) provide researchers with a very close match for participants variables, so are favoured
- not possible, so researchers must start with a large group of participants to increase chances of getting suitsbly matched pairs

Question 18

evaluation of experimental designs

evaluate a strength of repeated measures design

Answer 18

it is possible to remove participant effects. For example, if a person has 5 years driving experience in condition A (no alcohol) then they also have 5 years’ experience in condition B (alcohol), the participant variable is the same for both conditions. Therefore, any difference in their driving is due to the alcohol and not their experience

Question 19

evaluation of experimental designs

evaluate a weakness of repeated measures design

Answer 19

Repeated Measures design Order effects may occur when participants take part in more than one experimental condition. Order effects can confound the results in two ways - either negatively through the effects of fatigue or boredom, or positively through the effects of learning or practice.

Question 20

evaluation of experimental designs

evaluate a strength of matched pairs design

Answer 20

there are no order effects and there is a good attempt at controlling participant variables.

Question 21

evaluation of experimental designs

evaluate a weakness of matched pairs design

Answer 21

matching pairs of participants can be difficult and time consuming: It depends on the use of reliable and valid procedures for pre-testing participants to identify the matched pairs. Complete matching of participants on all variables that might affect performance can rarely be achieved.

Question 22

evaluation of experimental designs

evaluate a strength of independent groups design

Answer 22

avoids order effects altogether and also participants less likely to guess aims of study and show demand characteristics as they only take part in one condition.

Question 23

evaluation of experimental designs

evaluate a weakness of independent groups design

Answer 23

has no control for participant variables, which could influence experiment’s results

Question 24

Experimental variables

what are extraneous variables?

Answer 24

an experiment should try to establish control over factors that may have unwanted effect on the dependent variable. these other variables are known as extraneous variables

Question 25

Experimental variables

what are cofounding variables?

Answer 25

it confounds the result of the study is such a way that you are no longer measuring the effect of the IV on the DV

Question 26

Experimental variables

what are situational variables?

Answer 26

• These are variables connected with the research situation. For example, temperature, instructions, time of day and lighting, materials etc.
• Situational variables are controlled through standardisation ie ensuring that the only thing that differs between the two conditions is the IV.

Question 27

Experimental variables

what are participant variables?

Answer 27

• A participant variable is any characteristic of individual participants which may affect findings eg

Age, intelligence, motivation, experience
- Participants may perform better in one condition because they have certain characteristics not because of the IV they receive.

Gender
- Males and females differ psychologically, partly due to socialization.
- Research (Eagly, 1978) suggests women are more obedient than men, as they are more focused on group goals.
- Gender acts as an extraneous variable only in certain contexts.
- For example, gender is not controlled in memory experiments as there is no evidence of significant memory differences between men and women.

Irrelevant participant variables
- Only participant variables relevant to the task should be considered as extraneous variables.
- For instance, in a noise and memory task, liking spicy food would not be considered an extraneous variable.

Question 28

Experimental variables

what are demand characteristics?

Answer 28

Demand characteristics occur when participants try to make sense of the research situation they find themselves in and act accordingly.

This may include the following participant behaviour
- Trying to guess the purpose of the research and acting in a way that they feel is helpful (when it may not be) They may also decide to be unhelpful throughout.
- Acting nervously and out of character because of being in a research situation - for instance, participants may feel they are being evaluated in some way (e.g. that their personality is being assessed) and be anxious about this.
- Displaying social desirability bias by wanting others to see them in the most favourable way possible, e.g. in the responses given to a questionnaire on moral standards.

Question 29

Experimental variables

what are experimenter effects?

Answer 29

Investigator effects result from the effects of a researchers’ behaviour and characteristics on an investigation.
- Expectation effects can occur if a researcher is overly committed to a specific outcome, leading to misinterpretation of events. In naturalistic observation, the presence of the observer can influence participants’ behavior, making it less natural.
- In questionnaire surveys or interviews, various aspects of the investigator (e.g., age, gender, appearance, communication style) can influence participants. The way questions are asked or how the researcher responds may also guide participants to certain answers.

Question 30

controlling the issues of experimental variables

how do you control each of the experimental variables?

Answer 30

Situational variables:
- standardisation of procedure and instructions: every participant has had exactly the same experiences, therefore, results are reliable

Participant variables:
- change the experimental design: change it to repeated measures to minimise differences. change it to match pairs to aslo minimise differences between groups

Demand characteristics:
- single blind procedure and distractor task: participants will not be aware of their condition (experimental control) so likey to act more naturally. distracter task, throw participant off what the aim is

Investigator effects:
- double blind procedure: investigator behaviour will not influence participant behaviour

Question 31

Wilcoxon T-test

what was the Wilcoxon T-test? (what do you do?)

Answer 31

• you are testing for a difference
• there is a repeated measures design (related)
• the data is at an ordinal level of measurement

Question 32

Wilcoxon T-test

how do you calculate the T value for a Wilcoxon T-test?

Answer 32

1. calcuate the differences between the first and second condition. (make sure you show whether the difference are +ve or -ve
2. find the score with the smallest difference, assign it rank “1”. then find the score with the second smallest difference, assign it the rank “2” etc. if there are scores with similar differences, you give the average rank to each score. if there are scores with no differences, you omit that data point. it gets NO rank (cross it out).
3. each score now has a rank. add up all the ranks of the scores with positive differences. separately, add up all the ranks of the scores with negative differences
4. select the rank total which has the smallest value (this is the T value)

Question 33

Wilcoxon T-test

what do you say in the statement of significance for a Wilcoxon T-test?

Answer 33

As the calcualted value of T (…..) is less/greater than the critical value at 5% for a one/two tailes test (…..), we can conclude the results are significant/ not significant. This means…..

Question 34

Wilcoxon T-test

what is the rule for the critical value? the critical value table (may or may not be given in exam so look at the table and remeber it for 5%= 0.05 for both one and two tailed)

Answer 34

Critical value rule = the calculated value must be equal to or less than the critical value in this table for significance to be shown

Question 35

Mann-Whitney U test

what was the Mann-Whitney U test? (what do you do?)

Answer 35

• you are testing for a difference
• there is an independent groups design (unrelated)
• the data is ordinal or intervak/ratio

Question 36

Mann-Whitney U test

what is the equation to calcualte the U value? (given in the exam)

Answer 36

Ua = NaNb + Na(Na+1)/2 - ΣRa
and
Ub = NaNb + Nb(Nb+1)/2 - ΣRb

Question 37

Mann-Whitney U test

what do you need to know to use the critical table correctly for a Mann-Whitney U test?

Answer 37

• whether you need a one or two tailed test (depending on the hypothesis)
• what level of significance the psychologist is willing to accept (usually 0.05)
• what Na and Nb are (number of participants in condition A and B respectively)

Question 38

Mann-Whitney U test

what is the rule for the critical value? the critical value table (remeber it for 5%= 0.05 for both one and two tailed)

Answer 38

Critical value rule = the calculated value must be equal to or less than the critical value in this table for significance to be shown

Question 39

Mann-Whitney U test

what do you say in the statement of significance for a Mann-Whitney U test?

Answer 39

As the calcualted value of U (…..) is less/greater than the critical value at 5% for a one/two tailes test (…..), we can conclude the results are significant/ not significant. Therefore…..

Question 40

How do you choose the correct test?

Answer 40

Independent group experiment
- Nominal = Chi-squared (x^2)
- Ordinal (at least) = Mann Whitney (U)

Repeated measures/ matched pairs
- Nominal = N/A
- Ordinal (at least) = Wilcoxon (T)

Relationship (correlation)
- Nominal = N/A
- Ordinal (at least) = Spearman’s Rank (rho)