Research methods - Experiments: Variables and Design

Question 1

Describe what experiments are used for and how they work

Answer 1

one variable is manipulated by the experimenter and the effect of the change on another variable is measured. If there is a change, there is said to be a cause and effect relationship between the two variables.

Question 2

what are the three different types of experiments

Answer 2

laboratory experiments
field experiments
quasi experiments

Question 3

what is an aim

Answer 3

a general statement of the purpose of the study and highlights what the researcher intends to investigate

Question 4

define independent variables

Answer 4

the variable that the researcher manipulates

Question 5

define dependent variables

Answer 5

the variable that the researcher measures the effect of the IV on

Question 6

what must both variables be

Answer 6

fully operationalised

Question 7

Why is it important that both variables are fully operationalised

Answer 7

Allows for research to be replicated in the future

Question 8

Operationalise this: performance

Answer 8

Score out of 20

Question 9

Define the extraneous variable

Answer 9

When something else has the potential of affecting the dependent variable that is not the independent variable

Question 10

What are the four types of extraneous variable

Answer 10

Participant variables, situation variables , demand characteristics,
Researcher effects

Question 11

Define participant variables

Answer 11

These are the characteristics of an individual which may affect the dependent variable eg age

Question 12

Define situation variables

Answer 12

Features of the environment which may affect the dependent variable eg unexpected background noise

Question 13

Define demand characteristics

Answer 13

If participants work out the aims of the research study, they may begin to behave in a certain way

Question 14

Define researcher effects

Answer 14

The researcher may give away the aims of the research study eg body language

Question 15

how can it be ensured that these extraneous variables do not affect out independent variable

Answer 15

control them - making the variables the same for everyone they affect.
the more extraneous variables we control, the more likely we are to establish cause and effect

Question 16

what is a confounding variable

Answer 16

when researchers are unable to control an extraneous variable, making cause and effect near impossible to achieve

Question 17

what is a hypothesis

Answer 17

a prediction that researcher make about what they think will happen in their study - it is a statement that demonstrates the relationship between the IV and the DV

Question 18

what are the general rules when writing a hypothesis

Answer 18

future tense
include both conditions of the IV
include the DV

Question 19

define null hypotheses

Answer 19

these predict that no difference will be found in the results between the conditions - the IV will have no effect on the DV

Question 20

define experimental hypotheses

Answer 20

these predict that there will be a significant difference in the results between the two conditions

Question 21

what are one-tailed (directional) hypotheses

Answer 21

they predict the direction of results e.g participants who drink coke will recall more words than participants who do not drink coke

Question 22

what are two-tailed (non-directional) hypotheses

Answer 22

they do not predict the direction of results, but just state that there will be an effect

Question 23

how would you know whether to write a one-tailed or two-tailed hypothesis

Answer 23

if previous research has been conducted and it tells us the direction of the results, then we should write a one-tailed hypothesis
if there is not previous research or the results of previous research are inconclusive then we should write a two-tailed hypothesis

Question 24

what are the three experimental designs

Answer 24

independent measures
repeated measures
matched pairs

Question 25

why is experimental design important

Answer 25

the validity of an experiment is directly affected by how it is constructed

Question 26

describe the independent measures design

Answer 26

different ps take part in each condition of the independent variable. the ps remain independent from each other

Question 27

describe the repeated measures design

Answer 27

all of the ps take part in both conditions of the independent variable the ps repeat the experiment whilst taking part in all the conditions

Question 28

describe the matched pairs design

Answer 28

each ps is matched with a 'twin' who is similar to them, and one ps from each twin pair takes part in each condition ps are usually matched on characteristics that could affect the outcome of the experiment

Question 29

what are order effects

Answer 29

ps responses are affected by the order of conditions they are exposed to

Question 30

what is counterbalancing

Answer 30

a technique used to reduce order effects when using aa repeated measures design

Question 31

how does counterbalancing work

Answer 31

it varies the order in which ps take part in each condition of the IV ABBA as half the ps take part in condition A first, then do condition B and the other half do condition B first, then A

Question 32

what are strengths of the independent measures design

Answer 32

reduces the possibility of demand characteristics as ps only take part in one condition of the IV so less likely to guess aim avoids order effects

Question 33

what are weaknesses of the independent measures design

Answer 33

participant variables may influence the results of the study as there are different ps with different characteristics in each condition larger sample of ps required due to them only doing one condition

Question 34

how to deal with weaknesses of independent measures design

Answer 34

ps should be randomly allocated to conditions ie put names/numbers into a hat this means that ps variables should not cluster in one condition

Question 35

what are strengths of the repeated measures design

Answer 35

reduces the effect of participant variables as ps take part in both conditions fewer participants required

Question 36

what are weaknesses of the repeated measures design

Answer 36

ps may be able to guess the aim of the experiment and so may display demand characteristics due to taking part in both conditions order effects may impact outcome of study as ps take part in both conditions, they may become fatigued or bored and perform worse or may perform better due to practice

Question 37

how to deal with weaknesses of the repeated measures design

Answer 37

order effects can be reduced with counter-balancing

Question 38

what are strengths of the matched pairs design

Answer 38

reduces the effect of ps variables as ps are matched on key characteristics that researchers have identified could have an effect on the results avoids order effects

Question 39

what are weaknesses of the matched pairs design

Answer 39

will be difficult to control all ps variables as you can only match on variables identified as relevant AND there may be characteristics that cannot be matched time consuming

Question 40

how to deal with weaknesses of the matched pairs design

Answer 40

start with a large group of ps to increase the chances of being able to match ps on key variables