Sampling and Participants

Question 1

What is sampling?

Answer 1

The selection of participants from the sampling frame with the aim to create a representative selection of people from that group

Question 2

What is a sampling frame?

Answer 2

The source material from which a sample is drawn such as an electoral roll or telephone directory

Question 3

What is opportunity sampling?

Answer 3

The recruiting of people that are available, for example walking by someone in the street or students that are at your school

Question 4

What are the advantages of opportunity sampling?

Answer 4

It is these easiest as you will be using people that are available so it is less time consuming and easier to find people

Question 5

What are the disadvantages of opportunity sampling?

Answer 5

It is biased as it limits the sample group that is going to be representing a target population. For example, if you were to be out in town on a Monday morning looking for a sample, your sample would only be limited to people that possibly don’t work or have school. Any person that might be at work or in school would not be involved thus restricting the diversity of the sample group

Question 6

What is random sampling?

Answer 6

The sample group is taken through the use of the lottery method or a random number generator. The lottery method is when the names of everyone in a target population are put into a “hat” and a certain number of names are drawn. The researcher might allocate the first ten people to condition A and the next ten to condition B. The random number generator method is when the researcher numbers everyone in a target population and uses a random number generator to select different numbers. A person is chosen if the number matches theirs.

Question 7

What are the advantages of random sampling?

Answer 7

It is unbiased as all members of a target population have an equal chance of being selected

Question 8

What are the disadvantages of random sampling?

Answer 8

It can be quite time consuming as you would need to gather a list of names of everyone in a target population and then contact each individual drawn

Question 9

What is snowball sampling?

Answer 9

Current participants recruit further members who are people that they know thus creating a snowball effect

Question 10

What are the advantages of snowball sampling?

Answer 10

It enables a researcher to locate groups of people that are difficult to access such as drug addicts

Question 11

What are the disadvantages of snowball sampling?

Answer 11

The sample would not be a great representation of the target population as they participants would mainly consist of friends of friends

Question 12

What is self-selected sampling?

Answer 12

People that volunteer as a result of seeing an advertisement in a newspaper or on a noticeboard or on the Internet

Question 13

What are the advantages of self-selected sampling?

Answer 13

It gives access to a variety of participants, such as people that read a particular newspaper, which might make the sample more representative and less biased

Question 14

What are the disadvantages of self-selected sampling?

Answer 14

It is biased in other ways as the participants would mainly consist of those who are available with free time on their hands and/or motivation to volunteer. This is also known as volunteer bias

Question 15

What is stratified and quota sampling?

Answer 15

Subgroups (aka strata) are taken from a target population (such as boys and girls or a particular age group). Participants are then selected in proportion to their occurrence in the subgroups. Stratified sampling selection uses a random technique whereas quota sampling selection uses a non-random technique

Question 16

What are the advantages of stratified and quota sampling?

Answer 16

Likely to be more representative than other sampling methods as there is a proportional representation of subgroups

Question 17

What are the disadvantages of stratified and quota sampling?

Answer 17

It is very time-consuming as you would first need to select a subgroup and then select people from that subgroup and contact them

Question 18

What is systematic sampling?

Answer 18

Use a predetermined system to select participants, such as picking every fifth person from a list of people (possibly from a phone book) to represent the target population

Question 19

What are the advantages of systematic sampling?

Answer 19

It is unbiased as participants are selected using an objective system

Question 20

What are the disadvantages of systematic sampling?

Answer 20

Not truly unbiased/random unless use select a person using a random method and then choosing ever nth person afterwards

Question 21

What are repeated measure?

Answer 21

It is when the same group of participants are used in both condition A and B

Question 22

What are the advantages of repeated measures?

Answer 22

1. Participant variables (individual differences shown by every participant) which can become extraneous variables are kept consistent in each condition
2. As each participant is used in both conditions, less participants are required thus being more economical

Question 23

What are the disadvantages of repeated measures?

Answer 23

1. Order effects e.g. learning, fatigue and boredom may become constant errors when one condition is done after the other.
2. Demand characteristics. As a participant does both conditions, they might guess the aims and act differently as a result of doing so

Question 24

What are independent measures?

Answer 24

It is when different participants are used for each condition for example, group 1 completes condition A and group 2 completes condition B

Question 25

What are the advantages of independent measures?

Answer 25

1. Order effects such as learning, fatigue and boredom have no influence as each participant only does one condition
   2, Demand characteristics are less of a problem as they only complete one condition and so are naïve as to the outcome so they are less likely to guess

Question 26

What are the disadvantages of independent measures?

Answer 26

1. Participant variables differ which might act as extraneous variables unless they are controlled for
2. More participants are required as each are used thus being less economical

Question 27

What are matched pairs?

Answer 27

It is when different but similar participants are used in each condition. The researcher makes an effort to match each participant in each condition

Question 28

What are the advantages of matched pairs?

Answer 28

1. Participant variables are kept more constant between conditions
2. order effects do not occur as each participant only undergoes one condition
3. Demand characteristics are less of a problem as the participants only undergo one condition each

Question 29

What are the disadvantages of matched pairs?

Answer 29

1. Participant variables can never be perfectly matched
2. Matching participants can be very time consuming
3. As each participant is only used once, more are required and so it is less economical

Question 30

What is a target population?

Answer 30

It is a group of people that the researcher is interested in which results in them selecting people to represent that group of people in an experiment so that the findings can be generalised more accurately