Experimental method

Question 1

What’s an experiment?

Answer 1

research method where a causal relationship can be drawn because the IV is deliberately manipulated to observe the causal effect on the DV.

Question 2

What’s an aim

Answer 2

A general statement about what the researcher intends to study —> states the purpose if a study

Question 3

What’s a hypothesis

Answer 3

a precise statement which clearly states the relationship between the variables that are being investigated.

Question 4

What are the 4 types of hypothesis?

Answer 4

Directional (one tailed)
Non-directional (two tailed)
Experiment/ alternate
Null

Question 5

What’s a directional hypothesis?

Answer 5

predicts the nature of the effect of the independent variable on the dependent variable .
e.g. adults will recall more words than children

Question 6

What’s a non-directional hypothesis?

Answer 6

states an expected diffrence but not the direction of results e.g. there will be a difference between the number of words recalled by adults than by children.

Question 7

What’s an experimental/ alternate hypothesis?

Answer 7

A hypothesis in the context of an experiment —> predicts a difference or an effect between two variables.

Question 8

What’s a null hypothesis?

Answer 8

predicts there won’t be a difference or effect between two variables
e.g. there won’t be a difference between the number of words recalled by adults compared to children.

Question 9

What is an experimental design?

Answer 9

the different ways in which the testing of ppts can be organised in relation to the experimental conditions.

Question 10

What are the 3 experimental designs?

Answer 10

Independent groups
Matched pairs
Repeated measures

Question 11

What is independent groups?

Answer 11

Participants are randomly allocated into two conditions. One group does the experiment with variable 1, the other group does the experiment with variable 2. Results are compared.

Question 12

What’s repeated measures?

Answer 12

Participants are not divided into groups. Instead, all participants do the experiment with variable 1, then afterwards the same participants do the experiment with variable 2. Results are compared.

Question 13

What’s matched pairs?

Answer 13

all ppts take part in both conditions

Question 14

+/- IDG

Answer 14

-More ppts needed
-Least effective design for controlling extraneous or confounding variables.
+Reduces the chance of demand characteristics
+Random allocation

Question 15

+/- MP

Answer 15

-More ppts needed
-Not possible to match all ppt characteristics
+Use identical twins
+Good attempt to control ppt variables

Question 16

+/- RM

Answer 16

-Demand characteristics
-Ppts may guess the purpose of the experiment
+Fewer ppts needed
+Can reduce order effects through counterbalancing

Question 17

What’s counterbalancing?

Answer 17

A technique used to counteract order effects: ABBA half ppts do condition A then B and the other half do B then A.

Question 18

What’s the IV?

Answer 18

The variable that’s manipulated

Question 19

What’s the DV?

Answer 19

Measured

Question 20

What’s operationalisation?

Answer 20

How IV is manipulated and how DV is measured

Question 21

What’s an extraneous variable?

Answer 21

Additional variable to the IV that should be account for and controlled to avoid the impact on the DV.
E.g. time of day

Question 22

What’s a confounding variable?

Answer 22

A variable that may have impacted the study that hasn’t been controlled and may affect the nature of the study e.g. IQ

Question 23

What are demand characteristics?

Answer 23

Any cue that makes the ppt unconsciously aware of the aims of a study that helps ppts work out what the researcher expects to find.

Question 24

What are investigator effects?

Answer 24

Anything that an investigator does that has an effect on the ppts performance in a study other than what was intended.

Question 25

What’s randomisation?

Answer 25

Use of chance to reduce the effects of bias from investigator effects.

Question 26

What’s standardisation/ standardised procedures?

Answer 26

A set of procedure that are the same for all ppts in order for the study to be replicable

Question 27

How many types of experiment are there?

Answer 27

Lab Field Natural Quasi

Question 28

What’s a lab study?

Answer 28

An experiment in an artificial environment where variables can be strictly controlled.

Question 29

+/- lab

Answer 29

+high degree of control +replicable -experimenter bias -low ecological validity

Question 30

What’s a field experiment?

Answer 30

An experiment conducted in a natural environment but IV is still controlled.

Question 31

+/- field

Answer 31

+naturalistic +controlled IV -ethical considerations (informed consent) -loss of control

Question 32

What’s a Quasi experiment?

Answer 32

Experiment where the IV hasn’t been determined rather than instead of it naturally occurring e.g. gender difference studies

Question 33

+/- quasi

Answer 33

+controlled conditions -can’t randomly allocate ppts

Question 34

What’s a natural experiment?

Answer 34

An experiment in an in the IV isn’t brought about by the researcher and would’ve happened even if the researcher hadn’t been there. e.g. if studying reactions for to earthquakes

Question 35

+/- natural

Answer 35

+provides opportunities +high external validity -natural occurring events -very difficult to randomise

Question 36

What’s sampling?

Answer 36

The group of ppts the researcher is interested in / testing

Question 37

What are the 5 types of sampling?

Answer 37

Opportunity Random Systematic Stratified Volunteer

Question 38

What’s opportunity sampling?

Answer 38

Ppts happen to be available at the time of the study - recruited conveniently

Question 39

+/- opportunity

Answer 39

+time saving +cost efficient -not representative -researcher bias

Question 40

What’s random sampling?

Answer 40

When all members of the sample have an equal chance of being selected Uses methods: Lottery Random number generator

Question 41

+/- random

Answer 41

+no researcher bias -time consuming -volunteer bias: ppts can refuse to take so can end up with an unrepresentative sample

Question 42

What’s systematic sampling?

Answer 42

Every nth member is selected from the sample

Question 43

+/- systematic

Answer 43

+usually fairly representative -not truly unbiased

Question 44

What’s a stratified sample?

Answer 44

Composition of the sample reflects the varying proportions of people in a particular strata within the wider population

Question 45

+/- Stratified

Answer 45

+no researcher bias +representative data due to proportional strata -time consuming -identified strata can’t reflect all differences between people of the wider population

Question 46

What’s a volunteer sample?

Answer 46

Self selection - ppts offers to take part either in response to an advert or when asked to

Question 47

+/- volunteer

Answer 47

+easy and not time consuming +more likely to corporate in the study -volunteer bias

Question 48

What’s a pilot study?

Answer 48

Small-scale version of an investigation which is done before the real investigation is undertaken

Question 49

What’s a single-blind procedure?

Answer 49

A research method in which the researcher doesn’t tell the ppts if they’re given the treatment or placebo Avoids demand characteristics

Question 50

What’s a double-blind procedure?

Answer 50

Neither the experimenter or researcher knows who is receiving the treatment