RESEARCH DESIGN

Question 1

define internal validity

Answer 1

the soundness of a design

how strongly we can assert the changes in out DV to the IV

Question 2

define external validity

Answer 2

how generalisable the findings are

how representative of the world are the findings

Question 3

problem associated with internal vs. external validity

Answer 3

ensuring internal validity = means the potentially more artificial the study becomes = less externally valid

Question 4

4 steps to internal validity

Answer 4

sound operationalisation of DV

strong experimental design logic

sound operationalisation of IV

consideration and used of appropriate remedies to control for extraneous variables

Question 5

manipulation of the IV:

define experimental manipulation

Answer 5

participants allocated to an IV condition by the experimenter

Question 6

manipulation of the IV:

define individual differences manipulation

Answer 6

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

not strictly experimental

Question 7

what are the study designs

Answer 7

Repeated measures (within groups)
- each participants tested at each level of the IV

Between groups: each participant tested at only one level of IV

Factorial: more than one IV

Question 8

strengths of a factorial design

Answer 8

more than one IV allows for more precise hypotheses

control of extraneous variables by including as an IV

ability to determine the interactive effect of two or more independent variables

Question 9

weaknesses of a factorial design

Answer 9

using more than two independent variables may be logistically cumbersome

higher-order interaction are difficult to interpret

Question 10

what is separation and how is it achieved?

Answer 10

maximising the variation between groups

achieved by operationalisation of the IV

• need min. 2 IVs
• levels need to be distinctly separate
• additional intermediate levels can then be added to identify curvilinear impacts

Question 11

what is compression and how is it achieved

Answer 11

minimising the variation within groups

achieved by controlling extraneous variables

Question 12

what are the two forms of extraneous variables

Answer 12

noise creating

Confounding

Question 13

what are noise creating variables

Answer 13

extraneous variable that have:
no relation to the IV
but can randomly impact the DV to create extra variation in DV

Question 14

what are confounding variables?

Answer 14

extraneous variables that

• systematically impact the DV
• related to the IV
• potentially explain changes in DV that would be expected from the IV

Question 15

how can confounds be controlled for

Answer 15

eliminate impact by keeping the variable constant

or building it into the study to measure its impact

Question 16

what is the trouble with between group designs

Answer 16

two separate groups&raquo_space; participant groups that can differ in any way both relevant and irrelevant to the study

need to make the groups as similar as possible

Question 17

the issue of between groups design is addressed by…

Answer 17

selection - the process of assigning individuals to an experimental group

matching - equating participants in groups on specific variables

Question 18

what are the different methods of selection

Answer 18

self-assignment - participant select group

experimenter-assignment - experimenter selects group

Arbitrary assignment - based on seemingly irrelevant criteria

random assignment

Question 19

what are the pros of random assignment

Answer 19

ensures every member has an equal change of being assigned to either group

max insurance that groups are equal

eliminated systematic group differences

does not eliminate extraneous variables but randomly distributes them

Question 20

what is matching

Answer 20

using different techniques to equate participants in the groups on specific variables

should be done with variables thought to be related to/ confound the IV

e.g. intelegence, age, gender

Question 21

what are the two styles of matching

Answer 21

individual matching

distribution matching

Question 22

pros and cons of individual matching

Answer 22

PRO
- groups equate on potential extraneous variables

CON

• hard to identify what variables to match on
• more variables to match on = harder to match participants
• decreases generalisability of results

Question 23

what is blocking

Answer 23

building an EV into the design

• makes the EV another IV in the study
• should only be used when you are interested in the effect of the EV

Question 24

whats the PROS with repeated measures designs

Answer 24

Eliminate problem of group differences - major error source removed

require fewer participants to have good statistical power

Question 25

whats the problem with repeated measures designs

Answer 25

repeated measures can lead to sequencing effects

• order effects
• carry over effects

Question 26

what are the two order effects

Answer 26

practice effect
- when DV is based on performance (e.g. reaction time) improvement can be due to practice rather than the IV

Fatigue effect
- repeated completion of DV measure can lead to boredom or tiredness

Question 27

solution for order effects…

Answer 27

counter balancing

• break sample into subsets to experience different conditions in different orders
• then bring all data together to counteract sequencing effect

Question 28

different counter balancing procedures…

Answer 28

randomised

intra-subject - undergo all possible

complete - all possible used, undergo one

incomplete - formulated sequence

Question 29

what are the two carry over effects

Answer 29

simple - performance on DV in a condition is contaminated by he effects of the previous condition

differential - when carry-over effect of one condition differ depending on the order of condition completion

Question 30

why is counter balancing not always possible

Answer 30

some RM conditions or levels don’t allow for counter balancing

e.g. time as IV - DV is measured at different points in time

Question 31

issue of maturation as a carry over effect in time

internal event

Answer 31

changes due to natural development.improvement over time

must question whether improvement over time is form IV or naturally occurring

Question 32

issue of history as a carry over effect in time

Answer 32

external events that effect participants during study

socio-historical-economic changes relevant to DV

Question 33

what is statistical regression as a carry over effect in time

Answer 33

the tendency to move up or down towards the mean over time

likelihood of regressing to the mean (from above or below par) over repeated measures

Question 34

mortality as a carry over effect in time

Answer 34

not all participants who participate in the first measure will endure the whole duration of the study

common in longitudinal studies