Experimental design

Question 1

What are the goals of a psychological experiment

Answer 1

1)The goal of the study was to test a causal claim (hypothesis)
2)The causal factor (independent variable) was systematically varied (“manipulated”)
3)Other potential influencing factors were kept constant

Question 2

how can we conduct an experiment to support causal claims

Answer 2

if we observe a change in the DV it is because of the IV if we have changed it and everything else is kept the same. The IV is the cause of the change

Question 3

why should we be skeptic of causal claims

Answer 3

There is often an alternative explanation for observed changes in the dependent variable

Question 4

how could we describe the research being affected by another variable

Answer 4

the results were confounded by …..

Question 5

What is a confounding variable

Answer 5

an extraneous variable that has not been controlled for, that varies systematicallt with the IV and can explain changes in the DV

Question 6

Provide examples of a confounding variable

Answer 6

participant characteristics
situational variables

Question 7

What are experimenter expectancy effects

Answer 7

a confounding variable that occurs when a experimenter’s expectations about how ppts should behave in an experiment affects how the ppts behave

Question 8

What are subject expectancy effects

Answer 8

when ppts knowledge of the hypothesis or assumptions about it influences their behaviour

Question 9

How can we deal with confounding variables

Answer 9

standardisation
random allocation
blinding

Question 10

What is the proccess of standardisation

Answer 10

• standardise experimental procedures such as the study environment, instructions and stimulus in the material.This produces the same formalised procedures so all ppts are treated the same, so limitting the chance of extraneous variable will affect the ppts results.

Question 11

What is a double-bind study

Answer 11

Neither the experimenters, nor the participants know what group they are allocated to

Question 12

what is a single-blind study

Answer 12

Only the participants are naïve to the condition they are in

Question 13

what does binding protect against

Answer 13

subject and experimenter expectancy effects but it is not always possible

Question 14

What is a random allocation design

Answer 14

• randomly assigned to groups.
• people end up in the groups by chance, meaning that there is equal chance of being selected. Divides confounders/ extraneous variables across conditions

Question 15

When is random allocation impossible

Answer 15

some effects are naturally occuring for ppts and some experiments look at physical health. This would not be possible to manipulate and could be unethical to do so

Question 16

what design do we use when random allocation is not possible

Answer 16

natural groups design :Use naturally occurring groups
Natural groups do not keep potential confounders constant

Question 17

what is a matched group designs when random allocation is impossible

Answer 17

participants are matched on variables that could influence the results — these are called potential confounders and are randomly assigned to each groups ( make sure that there is enough ppts in each group), make sure that there are representative of the proportion of the people with that characteristic in the sample, . Keeps the variable you are measuring constant .

Question 18

what is a confounding variable in within-subjects designs

Answer 18

time can be . this can create something called order effects

Question 19

provide examples of order effects

Answer 19

Boredom / Fatigue
Practice
Habituation
Sensitization
Adaptation
Contrast

Question 20

What is counterbalancing overall

Answer 20

devide ppt into 2 groups
one group is administrated first, and then the second condition is administered.

Question 21

What is counter-balancing in reference to an incomplete within-subjects design

Answer 21

ounterbalancing in an incomplete within-subjects design varies the order and subset of conditions across participants, with each condition completed only once, to balance order effects such as practice effects.

Question 22

what is counterbalancing with a complete within-subjects design

Answer 22

Each participant experiences each condition multiple times and experiences all the conditions

Order of administration varies within participants
Practice effects are balanced within participants

Question 23

how can counter-balancing differ, and what ways can we use to counterbalance in reference to orders

Answer 23

how many permutations (possible orders) of conditions are being considered:
-all possible orders
-selected orders

Question 24

in counter-balancing why do we use selected orders

Answer 24

When there are too many conditions to use every possible order (complete counterbalancing), researchers use a subset of all possible orders

Question 25

what is the latin square in selected orders

Answer 25

A Latin square is a selected-orders counterbalancing technique in which each condition appears once in each position (row and column), reducing the number of orders needed while balancing order effects.

Question 26

what is the russain doll problem

Answer 26

In counterbalancing, the Russian Doll problem arises when conditions or factors are nested within each other, and trying to counterbalance them leads to impossible or overly complex combinations

Question 27

how do we resolve the russain doll problem

Answer 27

block randomization-where participants are divided into blocks, and within each block, the order of conditions is randomly assigned to ensure all conditions are tested equally and the effects of order are minimized. ## Footnote balancees order effects

Question 28

How do weresolve the russain doll problem with the ABBA design

Answer 28

-Start with a random block of conditions -The next block is the exact reverse of conditions -Take a random remaining block of conditions -The next block is the exact reverse of conditions … Until you are out of blocks

Question 29

what does the ABBA design balance

Answer 29

the practice effects- balanced across both conditions

Question 30

what are the limitations of counter-balancing

Answer 30

1) complete within-subject designs are time consuming 3) no protection against differential transfers 4) incomplete within-subjects designs can confound results because differences between participants may be mistaken for effects of the experimental conditions.een conditions

Question 31

What are differential transfers

Answer 31

Effects of one condition affect performance in subsequent condition

Question 32

differential transfers evaluation

Answer 32

Notoriously hard to control, so a time delay between conditions could help but this increases time cost. Does not occur in pure between-subject designs, but between-subject designs ( matched) require more participants for the same number of datapoints are susceptible to other types of confounding

Question 33

what is the difference between order effects and diffrential transfers

Answer 33

Order effects are "simple" effects of time only. For example, over time, people get tired (= boredom/fatigue effect) or better at tasks (=practice effect) or they get less sensitive to stimuli that are presented (= desensitization effect). Order effects can be controlled through counterbalancing. Differential transfer is an interaction of time and experimental condition. Doing something (e.g., learning a complex rhythm) in one experimental condition influences how participants behave in the next condition (e.g. learning a simple rhythm), but if the conditions were ordered differently (e.g., learning a simple rhythm, then a complex one) this would not happen. Differential transfer cannot be controlled through counterbalancing.