Exam 2

Question 1

Sample

Answer 1

The group of people taking part in a research investigation

Question 2

Populations

Answer 2

The groups of people who are the focus of the researchers interest from which a sample is drawn

Question 3

Representative

Answer 3

A sample which actually represents the population being studies

Question 4

Bias

Answer 4

A systematic distortion

Question 5

Generalisation

Answer 5

The extent to which findings and conclusions from an investigation can be applied to the population, made possible by a representative sample

Question 6

Pilot study

Answer 6

A small scale version of an investigation before the real investigation

Question 7

Aims of a pilot study

Answer 7

• to check a study will run smoothly and identify potential issues
• remove or re-word confusing or ambiguous words from interviews and questionnaires
• observers can be trained for observational studies

Question 8

Control groupds and conditions

Answer 8

A control group is used as a comparison to the experimental group

Question 9

Single - blind procedures

Answer 9

When participants are not told the aim of the study, and/or not told which condition they are in.

This is to control confounding variable and demand characteristics

Question 10

Double-blind procedure

Answer 10

Neither the participants nor the researcher conducting the experiment know the aim of the experiment.

This prevents the investigator from influencing the investigation with their expectations of the results.

Question 11

Random sample

Answer 11

All members of the target population have an equal chance of being selected in random sampling

Question 12

Systematic sample

Answer 12

Every nth number of the population is selected

Question 13

Stratified sampling

Answer 13

Where the composition of the sample reflects the proportions of people from different groups in the target population and are representative

Question 14

Opportunity sample

Answer 14

Anyone who is willing to take part in a study is selecred

Question 15

Volunteer

Answer 15

Participants will select themselves and volunteer to be part of the sample

Question 16

Strengths of random sampling

Answer 16

• unbiased
• confounding and extraneous variables are equally divided into different groups
• therefore these studies have high internal validity

Question 17

Limitations of random sampling

Answer 17

• time consuming
• sample may still be unrepresentative because of probability
• some participants may refuse to take part, leading to unrepresentative sample, and more like a volunteer sample

Question 18

Systematic sample strengths

Answer 18

• objective

- researcher has no influence over the sample after the method has been selected

Question 19

Systematic sample limitations

Answer 19

• time consuming

- if participants drop out it will be more like a volunteer sample

Question 20

Stratified sample strengths

Answer 20

• very representative of the population as it actually reflects the composition of differen strata
• the results can be generalised to the larger population

Question 21

Stratified sample limitations

Answer 21

• cant reflect and represent every way people are different, so it is impossible to completely represent the target population

Question 22

Opportuinity sampe strengths

Answer 22

• convenient. Takes less time and money than other sampling methods

Question 23

Opportunity sample limitations

Answer 23

• can be biased. Sample is unrepresentative of the target population as it it taken from one specific area
• the results cant be generalised to the larger target population
• reseracher has complete control over who is approached to take part in the study

Question 24

Volunteer sample strengths

Answer 24

• very little effort by the researcher needed
• less time consuming than other sampling methods
• participants are more engaged becuase they have requested to be in the study

Question 25

Volunteer sample limitations

Answer 25

• volunteer bias may effect results
• volunteers are more likely to be interested in the topic of research, and therefore be more likely to try and please the researcher
• this gives unrepresentative results so it is hard to generalise the findings

Question 26

Correlation

Answer 26

A mathematical technique where a reseracher investigates an association between two variables (co-variables)

Question 27

Co-variables

Answer 27

-the variables investigated within a correlation, for example height and weight. They are not referred to as the independent and dependent variables because a correlation investigates the association between the variables, rather than trying to show a cause-and-effect relationship

Question 28

Positive correlation

Answer 28

As one covariable increases so does the other

Question 29

Negative correlation

Answer 29

As one co-variable increases the other decreases

Question 30

Zero correlation

Answer 30

When there is no relationship between the co-variables

Question 31

Analysis of covariables

Answer 31

Correlations can be analysed using statistical tests. When calculated, the correlation has a value between -1 and +1 - the correlation coefficient. This tells us the strength and direction of the relationship between the two variables. +1 is a perfect positive correlation, and -1 is a perfect negative correlation. The closer to +1 or -1, the strongest the relationships between the co-variables. Weak correlations can be significantly significant