Research Methods: L6-8

Question 1

Target population

Answer 1

Describes the group the researchers are studying and want to generalise their results to

Question 2

A sample

Answer 2

Should be representative of the population it was drawn from

Question 3

Random sampling

Answer 3

When every member of the target population has the same chance of being selected

Question 4

Advantage of random sampling

Answer 4

• The results can be generalised to the target population
• No researcher bias when selecting the sample

Question 5

Disadvantages of random sampling

Answer 5

• Difficult to get full details of the target population to get a sample from
• Not all selected members will be able or willing to take part

Question 6

Systematic sampling

Answer 6

Sampling strategy where pps are selected by taking ever Nth person from a list

Question 7

Systematic sampling advantages & disadvantages

Answer 7

Advantage
- More simple than random sampling

Disadvantage
- Selection can interact with a hidden periodic trait of the population -> the sample is no longer random
- Not all pps may be willing or able to take part -> unrepresentative sample

Question 8

Stratified Sampling:

Answer 8

Stratified sampling involves classifying the population into categories and then randomly choosing a sample which consists of participants from each category in the same proportions as they are in the population

Question 9

Stratified sampling advantages and disadvantages

Answer 9

Advantage:
All groups within a population are included, therefore the sample should be representative of the population.

Disadvantage:
Stratified sampling can be very time consuming as the categories have to be identified and calculated. If you do not have details of all the people in your target population or the relevant strata, you would struggle to conduct a stratified sample.

Question 10

Opportunity Sampling:

Answer 10

Opportunity sampling involves selecting participants who are readily available and willing to take part.

Question 11

Opportunity Sampling advantages and disadvantages

Answer 11

Advantage:
This is the easiest method of ensuring large samples especially when compared to stratified sampling which might be very time consuming and expensive to carry out.

Disadvantage:
There is a high chance that the sample will not be representative of the target population. Sometimes people feel obliged to take part in research even when they do not really want to, this is unethical

Question 12

Volunteer Sampling

Answer 12

Volunteer sampling involves people volunteering to participate in a study. The researcher will usually advertise for people to take part in their research.

Question 13

Volunteer Sampling advantages and disadvantages

Answer 13

Advantage:
This method saves the researcher time and effort. The researcher needs to construct some kind of advertisement for the study and then just needs to wait for the participants to come to them. This is better than other sampling methods where the researcher needs to ask people to take part and needs their full commitment.

Disadvantage:
A certain type of person tends to volunteer (enthusiastic, interested in your topic) and this means that there is a very high chance that the sample obtained will be unrepresentative and will not accurately reflect the target population (volunteer bias).

Question 14

Pilot studies

Answer 14

A pilot study is an initial run-through of the procedures to be used in an investigation; it involves selecting a few people and trying out the study on them. It is possible to save time, and in some cases, money, by identifying any flaws in the procedures designed by the researcher.

Question 15

Pilot studies advantages and disadvantages

Answer 15

Advantages:
Identifying any potential problems can save time and money

Disadvantage:
It can be misleading due to the small scale

Question 16

Experimental Designs:

Answer 16

The experimental design of a study is how the participants are organized within the experiment. There are three main types:

Independent groups
Repeated measures and
Matched pairs.

Question 17

Experimental condition:

Answer 17

This involves a group of people who are exposed to the independent variable e.g. chocolate or noise.

Question 18

Control condition:

Answer 18

This group receives no treatment and are used as a base line level to compare results against e.g. the group that receive no chocolate (no treatment)

Question 19

Controls:
Randomisation:

Answer 19

The use of chance in order to control for the effects of bias when deciding the order of conditions.

For example, to make sure that a list of words are not too easy or too hard, it is a good idea to put them in random order which can be done through a computer or manually. This is especially important if you are using a repeated measures design and the same participants are taking part in two different conditions.

Question 20

Controls:
Standardisation:

Answer 20

Using exactly the same formalised procedures and instructions for all participants in a research study – this improves the reliability of the study

Question 21

Controls:
Random allocation:

Answer 21

An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition or the other

Question 22

Independent Groups Design:

Answer 22

In this design, different participants are used in each of the conditions. Therefore each group of participants are independent from one another.
Participants are usually randomly allocated to each condition to balance out any individual differences.

An example might be that we put 20 participants’ names in a hat. We draw out the first name and they will go into group 1, the second person goes into group 2, the third person goes to group 1 etc.

Question 23

Independent Groups Design advantages

Answer 23

1) Order effects will not occur as there are different pps in each condition. Order effects are when the sequence in which participants take part in conditions influences their performance or behaviour. Eg IQ test (people might get better or worse)

2) The chance of demand characteristics is reduced as participants take part in only one condition each and so have less chance to guess the aim of the study which could affect their behavior and the data collected.

3) Participants are not lost between conditions/trials because they only take part in one condition only and then leave the experiment/study.

Question 24

Independent Groups Design disadvantages

Answer 24

1) More participants are needed for this experimental design compared to a repeated measures design. In an independent groups design there are usually 2 experimental conditions (or more) with different participants in each group

2) There is always a chance that the different results gained between the two conditions are due to individual differences rather than manipulation of the IV. This is because two separate groups of people are used and they might be very different.

Question 25

Repeated Measures design:

Answer 25

In the repeated measures design each participant is tested in all conditions of the experiment.

For example one group might be tested today to see what effect chocolate has on their mood. The same group of people are tested again next Friday to see the effect of chocolate on their mood.

Question 26

Repeated Measures design advantages

Answer 26

1) As the same people are used in all of the conditions, there are no individual differences between the conditions. Therefore the study is more valid as we are really only measuring the effect of the IV on the DV.

2) Half as many pps are needed in this design compared to an independent groups design.

This is because one group of participants e.g. (20) are used in condition 1 and again in condition 2. However an independent groups design would need 20 participants in condition 1 and 20 participants for condition 2.

Question 27

Repeated Measures design disadvantages

Answer 27

1) Order effects may affect the results. One way to avoid order effects is counterbalancing, this is when half the participants do condition A first and then condition B second and the other half of the participants do condition B first and condition A second. Changing the order of the tasks helps to reduce order effects and negative impacts on data collection.

2) Demand characteristics are more likely to occur using repeated measures design as participants are involved in the entire study and take part in two conditions. They might guess the aim of the study and therefore this might affect their behavior and the data collected.

Question 28

Matched Pairs Design:

Answer 28

In the matched pairs design, different participants are used in all of the conditions, just as with the independent groups design.
However, participants in the two groups are matched on characteristics important for that study, such as age, gender, level of education etc. Identical twins are often used in matched pairs designs.

Question 29

Matched Pairs Design advantages

Answer 29

1) There is less risk of order effects using a matched pairs design as participants only take part in one conditions only (compared to repeated measures design).

2) Individual differences are less likely to occur as the groups have been closely matched on specific characteristics (less likely to occur compared to independent groups design).

Question 30

Matched Pairs Design disadvantages

Answer 30

1) Twice as many participants are required compared with a repeated measures design. Researchers need to gain access to a large number of participants, as different participants will appear in each condition, therefore this can be difficult in order to locate and use enough people to take part in the study.

2) The matching process is incredibly difficult and time consuming; even two closely matched individuals have different levels of motivation and fatigue at any given time. Therefore individual differences cannot be completely controlled and removed.

Question 31

Reliability

Answer 31

Reliability refers to the consistency of a research study especially when a study is repeated again and the same results are gained on both occasions.

Question 32

External Reliability:

Answer 32

This is whether a test and the results gained are consistent over time.

The test-retest method can be used to assess external validity. A research study is conducted once, and then it is conducted again in the future. If the results gained from the both tests are similar then the study can be said to be reliable.

Question 33

Internal Reliability:

Answer 33

This is whether a test and the results gained are consistent within itself.

The split-half technique assesses the internal reliability of questionnaires.
The questionnaire is split in half and if participants score similarly on both halves of the questionnaire then the questions are measuring the same factors and the questionnaire has internal reliability.

Question 34

Validity

Answer 34

Validity means that a study is measuring what it intends to measure when referring to the aim of the study.

Question 35

External Validity: (Ecological validity)

Answer 35

This is the extent to which the findings of a study can be generalised to other settings.

Question 36

Participant validity:

Answer 36

The results from the participants used in the study can be generalised to the target population

Question 37

Temporal validity:

Answer 37

The results from the study can be generalised to people in today’s contemporary society

Question 38

Internal Validity:

Answer 38

This is when the outcome of the study is a direct result of the manipulation of the independent variable (IV) upon the dependent variable (DV) and has not been affected by extraneous variables (EV).

Question 39

Control of Extraneous Variables:

Answer 39

In order to ensure that a study has internal validity, extraneous variables must be well controlled

Question 40

Participant Variables:

Answer 40

These are characteristics of the participants which may affect the DV (e.g. intelligence, age etc.). Choosing an appropriate experimental design can help to try and overcome these type of extraneous variables. Matched pairs and repeated measures design can help to avoid participant variables.

However, repeated measures can lead to order effects, so counterbalancing should be used to avoid this. Random allocation of participants to conditions (e.g. names out of a hat) should also ensure that groups are not biased.

Question 41

Situational Variables:

Answer 41

Factors in the environment where the experiment is conducted that could affect the dependent variable (e.g. temperature, time of day, lighting, noise etc.).

A way to resolve this issue is to use standardisation (i.e. making sure that all the conditions, materials, and instructions are the same for all pps).

Question 42

Experimenter Variables:

Answer 42

These are factors to do with the experimenter which can affect the dependent variable, for example personality, appearance, and conduct of the experimenter.

Standardised instructions should ensure that the experimenter acts in a similar way with all participants and follows a script and speaks to everyone in the same manner and tone.

Question 43

Investigator Effects:

Answer 43

Investigators may inadvertently influence the results of their research. Certain physical characteristics of the investigator, such as age, gender and ethnicity can influence the behaviour of participants which therefore affects the data that is collected from the research.

If investigators know the hypothesis they may also inadvertently be biased in their interpretation of the results. (Observer bias and interviewer effects are a type of investigator effects.)

Question 44

How can investigator effects be overcome

Answer 44

The double blind technique. This is when neither the participants nor the investigator knows the aim of the study and hopefully this will mean the data collected will be more valid.

Question 45

How can demand characteristics be overcome

Answer 45

Demand characteristics can be overcome by the single blind technique. This involves making sure pps do not know what the aim of the study is so that hopefully this will not influence their behaviour unduly. This is more difficult to accomplish in a repeated measures design.