Research Methods

Question 1

Ethics definition

Answer 1

Moral principles that govern a persons behaviour or how they conduct an activity.

Question 2

Name ethical issues

Answer 2

Lack of informed consent, Deception, Protection of participants from harm, Confidentiality, Debriefing, Privacy, Right to withdraw

Question 3

How does the ‘British Psychological Society’s Code of Ethics’ help deal with ethical issues?

Answer 3

BPS regularly updates its ethical guidelines which tells psychologists what behaviours are not acceptable and give guidance.

Question 4

How do universities and other institutions where research is carried out help with ethical issues?

Answer 4

They have ethics committees to ensure that the rights of all participants are respected.

Question 5

How is informed consent dealt with?

Answer 5

Participants are asked to formally indicate their agreement.
Prior general consent - participants are told that they may be deceived about the true purpose of the study. Only the ones who agree will take part.

Question 6

How is deception dealt with?

Answer 6

The need for deception should be approved by an ethics committee.
Participants should be fully debriefed after the study and given the opportunity to withhold their data.

Question 7

How is the Right to Withdraw dealt with?

Answer 7

Participants told at the beginning of the study that they have the right to withdraw at any time.
They should also be told that they have the right to withdraw their data.

Question 8

How is protection from harm dealt with?

Answer 8

Any risk greater than every day life should be avoided.
Stop the study if it has more of an effect on participants than originally expected (e.g. Stanford Prison Experiment by Zimbardo).

Question 9

What are laboratory experiments?

Answer 9

Experiments conducted in a lab in a controlled environment whereby the independent variable is manipulated, whilst all other extraneous variables are strictly controlled.

Question 10

What are the strengths of laboratory experiments?

Answer 10

Easy to control extraneous and independent variables.
Easy to replicate if carried out well and reported clearly. Meaning it can be done again and if results are similar confidence is increased in the study.

Question 11

What are the limitations of laboratory experiments?

Answer 11

Loss of ecological validity - High level of control means the experiment becomes artificial producing unnatural behaviour.
Demand characteristics - participants try and make sense of the situation and act accordingly.

Question 12

What are field experiments?

Answer 12

Experiments in a natural setting, rather than the comparatively artificial setting of the lab. Consequently, extraneous variables are difficult to control.

Question 13

What are the strengths of field experiments?

Answer 13

Improved ecological validity - natural setting so reflects real life.
Reduction of demand characteristics - usually unaware they are being studied.

Question 14

What are the limitations of field experiments?

Answer 14

Extraneous variables - in the real world you cannot control them making it hard to replicate exactly the same.
Ethical issues - as they are unaware the are being studied they cannot give informed consent.

Question 15

What are natural experiments?

Answer 15

Experiments where the IV occurs naturally but what is being tested only happens to certain people e.g. gender, the effect a bad childhood has on a person or schizophrenia.

Question 16

What are the strengths of natural experiments?

Answer 16

Study of sensitive issues - it allows research where an IV can’t be directly manipulated.
High external validity - these studies usually involve the study of real life issues and problems as they happen, meaning they are more realistic.
Less demand characteristics.

Question 17

What are the limitations of natural experiments?

Answer 17

Loss of control - no control over extraneous variables meaning that is it difficult to replicate.
Expensive and time consuming.
Desired behaviour being displayed.

Question 18

What are quasi experiments?

Answer 18

Experiments where the IV occurs naturally and the variables simply exist e.g. being old or young - age.

Question 19

What are the strengths of quasi experiments?

Answer 19

Carried out under controlled conditions so same strengths of a laboratory experiment.
Easy to control extraneous and independent variables.
Easy to replicate if carried out well and reported clearly.

Question 20

What are the limitations of quasi experiments?

Answer 20

Cannot randomly allocate participants to conditions and therefore may be confounding variables.

Question 21

Aims definition

Answer 21

The general investigative purpose of the study.

Question 22

What are the IV and the DV?

Answer 22

The independent variable is manipulated by the experimenter. The dependent variable is the one which is measured by the experimenter.

Question 23

Hypotheses definition

Answer 23

Every experiment must have two clear statements: the null hypothesis and the alternative hypothesis.
Null - IV no effect on DV.
Alternative - IV will have an affect on DV.
- non-directional - no prediction.
- directional - prediction.

Question 24

What are extraneous variables?

Answer 24

The variables that have an effect on the DV that isn’t the IV. They are essentially nuisance variables - the ones that aren’t a major problem.

Question 25

What are confounding variables?

Answer 25

The variables that the researcher failed to control, they are the bigger problems that effect the DV.

Question 26

What are the demand characteristics?

Answer 26

Participants try and make sense of the new situation and act in the way they think is expected.

Question 27

What are investigator effects?

Answer 27

Unwanted influences on the experiment which effects the research outcome.

Question 28

What is randomisation?

Answer 28

Used to minimise the effect of extraneous/confounding variables on the outcome. The chance to reduce the researchers influence.

Question 29

What is standardisation?

Answer 29

All participants should be subject to the same environment, information and experience.

Question 30

What is meant by the term Random allocation?

Answer 30

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 as any other.

Question 31

What is meant by the term Counterbalancing?

Answer 31

An attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order.

Question 32

What is a repeated measure?

Answer 32

A repeated measure design involves using the same subjects in each condition of an experiment.

Question 33

What are the strengths of repeated measures?

Answer 33

+Subject variables - individual differences shown by every subject e.g. intelligence is kept constant between condition.
+Better statistical tested can be used because of less variation between conditions.
+Fewer subjects are required therefore it is more economical.

Question 34

What are the weaknesses of repeated measures?

Answer 34

• Order effects - learning or boredom may become constant errors when conditions done one after another - better due to practice.
• Demand characteristics - participants may guess the aim if done twice so act differently.

Question 35

What is a independent measure?

Answer 35

An independent measures design involves using different subject in each condition of the experiment.

Question 36

What are the strengths of independent measures?

Answer 36

+Order effects - learning or boredom do not influence as only one condition.
+Demand characteristics - less of a problem as subject only participants in one condition - less likely to guess the aim.
+Same test can be used e.g. memory test.

Question 37

What are the weaknesses of independent measures?

Answer 37

• Subject variables differ - which could become confounding variables unless controlled for.
• Worse statistical tests can be used because of more variation between conditions.
• More subjects are required (because each is used only once) and it, therefore, less economical.

Question 38

What are matched pairs?

Answer 38

A matched pair design involves using different but similar subject in each condition.

Question 39

What are the strengths of matched pairs?

Answer 39

+Subject variables are kept more constant between conditions.
+Better statistical tests can be used because of less variation.
+Demand characteristics are less of a problem as only exposed to one condition.
+Same test can be used e.g. memory test.
+No order effects as only one condition each.

Question 40

What are the weaknesses of matched pairs?

Answer 40

• Subject variables can never be perfectly matched in every respect.
• Matching subjects is very time consuming and difficult.
• More subject required therefore less economical.

Question 41

What is a random sample?

Answer 41

A technique for obtaining participants, whereby every member of the population has an equal chance of being selected.

Question 42

What are the strengths of a random sample?

Answer 42

It is unbiased as all members of the population have an equal chance of selection.

Question 43

What are the limitations of a random sample?

Answer 43

It is difficult and time consuming to conduct; it does not guarantee a representative sample, and selected participants may refuse to take part.

Question 44

What is a systematic sample?

Answer 44

A sample collected in a sequence so when every nth member of the target population is selected.

Question 45

What are the strengths of a systematic sample?

Answer 45

This avoids researcher bias and is usually fairly representative.

Question 46

What are the limitations of a systematic sample?

Answer 46

This is less effective than random sampling because it can’t be claimed that every member of the population is equally likely to be selected.

Question 47

What is a stratified sample?

Answer 47

A sample reflecting the composition of the population, for instance 20 per cent left hands individuals, 80 per cent right handed individuals in the population would determine a selection of participants using the same percentage.

Question 48

What are the strengths of a stratified sample?

Answer 48

Produces a representative sample as it is designed to accurately reflect the composition of the population. This means that generalisation of findings becomes possible. It also avoids researcher bias.

Question 49

What are the limitations of a stratified sample?

Answer 49

It is very consuming.

Question 50

What is a opportunity sample?

Answer 50

A sampling technique not based on random selection or probability; the researcher selects those who are convenient to him or her as respondents.

Question 51

What are the strengths of a opportunity sample?

Answer 51

It is convenient and less costly in terms of time and money that other sampling techniques.

Question 52

What are the limitations of a opportunity sample?

Answer 52

Researcher bias as it is completely controlled. Unrepresentative as specific area therefore difficult to generalise beyond the sample.

Question 53

What is a volunteer sample?

Answer 53

A sample of participants that select themselves by volunteering.

Question 54

What are the strengths of a volunteer sample?

Answer 54

It requires minimal input from the researcher and is less time consuming than other forms of sampling.

Question 55

What are the limitations of a volunteer sample?

Answer 55

Volunteer bias is a problem as participants are more likely to be helpful, keen and motivated that non-volunteers.

Question 56

What is a pilot study?

Answer 56

Pilot studies are small, trial versions of proposed studies to test their effectiveness and make improvements.

Question 57

What are the positives of a pilot study?

Answer 57

They are helpful in identifying potential issues early, which can be refined before committing to the length and expense of the full study.

Question 58

What is a single-blind procedure?

Answer 58

Where participants may not be told the aim at the beginning. All the attempts to control the effects of demand characteristics.

Question 59

What is a double-blind procedure?

Answer 59

Where neither the participants nor the researcher is aware of the aims of the investigation. This controls both demand characteristics and investigator effects.

Question 60

What are naturalistic observations?

Answer 60

An observation study conducted in the environment where the behaviour would normally occur.

Question 61

What are controlled observations?

Answer 61

An observation study where the researcher control some variables - often takes place in laboratory setting.

Question 62

What are the general advantages of observations?

Answer 62

-Value as a preliminary research tool - careful use of naturalistic observations can lead to identification of in the appropriate hypothesis for further research or may help to save time being wasted on unnaturalistic experiments.
Validity - well performed naturalistic observations can provide a useful check on whether experimental findings apply outside laboratory conditions. This is because they have greater ecological validity.

Question 63

What are the general disadvantages of observations?

Answer 63

Lack of cause and effect - there is no IV and the level of control over potential confounding variable is poor, therefore it is not possible to establish cause and effect from this method.
Observer effects - it is possible that the presence of an observer may affect participants behaviour. Also, the potential exists for bias on the part of the observer through their expectation or interpretations of events.
Categorisation of data - this may be difficult when the behaviour being studies is complicated. For example a child hitting another could be categorised as aggressive or rough and tumble play.

Question 64

What are structured observations?

Answer 64

An observation study using predetermined coding scheme to record the participants’ behaviour.

Question 65

What are unstructured observations?

Answer 65

Observation where there is no checklist so every behaviour seen is written down in an much detail as possible.

Question 66

What is a questionnaire?

Answer 66

A set of written questions that participants fill in themselves.

Question 67

What are the advantages of questionnaires?

Answer 67

Simplicity - once constructed and piloted, questionnaires can be carried out with minimum of training. Specialist administers are not to gather the information. This is a real advantage when compared with interviews, experiments and observations.
Speed - a large amount of data can be gathered from large numbers of participants relatively cheaply and in a short period of time.

Question 68

What are disadvantages of questionnaires?

Answer 68

Problems with question wording - it is difficult to produce questions that do not have some problems. For example, they may be ambiguous and therefore be interpreted differently by participants or they may be leading, directing participants to respond in a certain way.
Unreliable responses - participants may not answer questions accurately. For example, they might show social desirability effects, they may give responses that they think the research is looking for or they may deliberately lie.
Representative sample - response rates to questionnaires tend to be quite low. Those that choose to respond will be a biased sample - literate individuals who are clinics to spend time filling them in.

Question 69

What are open questions?

Answer 69

Questions where there is no fixed responses and participants can give answer they like. They generate qualitative data.

Question 70

What are closed questions?

Answer 70

Questions where there are fixed choices of responses e.g. yes/no. They generate quantitative data.

Question 71

What is meant by qualitative data?

Answer 71

Describes information that is expressed in words.

Question 72

What is meant by quantitative data?

Answer 72

Information that can be measured and written down with numbers.

Question 73

What is a interview?

Answer 73

Involves asking a variety of questions in a face to face setting between the participant and the researcher.

Question 74

What is meant by structured interviews?

Answer 74

Interview where the questions are fixed and the interviewer reads them out and records the responses.

Question 75

What are the advantages on structured interviews?

Answer 75

Can collect rich, detailed information, which would not be possible to obtain in an experiment.
This procedure can be easily repeated as the questions are fixed.

Question 76

What are the disadvantages of structured interviews?

Answer 76

Interviewer effects: the interviewer’s expectations or personal characteristics may influence the answer the interviewee gives.
Participants may show a social desirability effects.

Question 77

What is meant by unstructured interviews?

Answer 77

There are not fixed questions just general aims and it is more like a conversation.

Question 78

What are the advantages of unstructured interviews?

Answer 78

Can collect rich, detailed information, which would not be possible to obtain in an experiment.
This procedure allows for greater flexibility. The interview tailors questions to the responses of the interviewee so that issues can be explored in depth.

Question 79

What are the disadvantages of unstructured interviews?

Answer 79

Interviewer effects: the interviewer’s expectations or personal characteristics may influence the answer the interviewee gives.
Participants may show a social desirability effects.

Question 80

What is meant by semi-structured interviews?

Answer 80

Interview that has started some pre-determined questions, but the interviewer can develop others in responses to answers given by the participant.

Question 81

What are the advantages of semi-structured interviews?

Answer 81

Can collect rich, detailed information, which would not be possible to obtain in an experiment.
This procedure allows a little flexibility. The interviewer tailors questions to the responses of the interviewee so that issues can be explored in depth.

Question 82

What are the disadvantages of semi-structured interview?

Answer 82

Interviewer effects: the interviewer’s expectations or personal characteristics may influence the answer the interviewee gives.
Participants may show a social desirability effects.

Question 83

What are correlations?

Answer 83

Correlation illustrates the strength and direction of an association between two co-variables. Co-variables are the things that are being measured. It refers to a statistical analysis of scores that are paired (i.e. the co-variables) for example, hours spent watching violent TV and the number of anti-social behaviours performed in a week. It is a non-experimental technique and therefore, does not identify cause and effect, but rather, the relationship strength and direction between two naturally occurring variables.

Question 84

What are the key points of correlations?

Answer 84

• A correlation tells us whether 2 variables are related.
• A positive correlation is when high values on 1 variable are associated with high values on another variable.
• A negative correlation is when high values on 1 variable are associated with low variables on another.
• Correlations vary from +1 to -1 and can be more accurately detected using a statistical test such as Spearman’s rho.
• The closer the value is to 1, the stronger the correlation.
• A zero correlation is when there is no relationship between 2 variables.
• A correlatgvtion can be displayed on a scatter graph.

Question 85

What are the advantages of correlations?

Answer 85

+ A correlation is a useful way to examine variables that cannot be manipulated experimentally for practical or ethical reasons.
+ E.g. Stressful life events and heart disease.
+ Aggression score and time spent in day care.

Question 86

What are the disadvantages of correlations?

Answer 86

• A correlation does not mean there is a cause and effect relationship between the 2 variables.
• Even if 2 variables are strongly correlated this does not mean that a change in one variable causes a change in the other.
• E.g. hours of violent TV watched and scores on an aggressive scale.

Question 87

What is an experiment?

Answer 87

An experiment manipulates (changes) an independent variable, measures a dependent variable while keeping all other variables constant.
This enables cause and effect to be established.
A change in one variable causes a change in the other.

Question 88

What is the difference between correlation and experiments?

Answer 88

Correlations, unlike experiments, are not looking for a difference in the results as a consequence of what has been manipulated by the researcher. Rather, they are looking for the relationship between 2 co-variables i.e. as one increases, what happens to the other one?
As there is no manipulation of an IV, it is not possible to establish a cause and effect relationship between one co-variable and another. For example there is a relationship between the colour of grass and ice-cream sales. The more yellow the grass gets the more ice cream is sold. However, in this case the causal variable is obviously temperature.
Psychologists have suggested a correlation between watching TV violence and aggressive behaviour. This does not suggest that TV violence causes aggressive behaviour simply that there is a relationship between them.

Question 89

What are the advantages of experiments?

Answer 89

+ Detecting Patterns - it is a useful method for detecting patterns in data and seeing how 2 variables relate to each other. From this, predictions can be made about the likely value of one variable when we only have information about the other.
+ Eliminating cause and effect - although correlations cannot establish cause and effect they can eliminate it. If no association is found, it can be said that there is no cause and effect between the two variables being studied.
+ Large amounts of data - it is often possible to obtain amounts of data on a number of variables more rapidly and efficiently than with experimental designs.

Question 90

What are the disadvantages of experiments?

Answer 90

• Cannot establish cause and effect - we cannot say which of the variables led to a change in the other or whether a third variable was involved.
• Curvilinear relationships - simple correlation analysis is unable to pick this up. Care must be taken to examine the scatter graph to ensure that it shows an appropriate linear pattern.

Question 91

What is validity?

Answer 91

Validity – refers to the extent to which something measures/investigates what it’s supposed to measure. For example, does a personality test really measure personality?

Question 92

What is internal (experimental) validity and external (ecological) validity?

Answer 92

• Internal (experimental) validity - This refers to the experiment itself. A researcher needs to ask whether it really was the independent variable that produced the change in the dependent variable. In other words, is it a genuine effect? To make sure that it is a genuine effect researchers must keep all confounding variables under control. The greater control over these variables the more confident the researcher can be that the experiment is valid.
• External (ecological) validity - This refers to the extent to which research findings can be generalised. A research study that has high external validity can be generalised to other populations, settings and times. Researcher can increase the external validity of their study by using a wider sample, by partially replicating a study or by making it more realistic.

Question 93

What is reliability?

Answer 93

Reliability – refers to consistency. Without reliability of a measure, the data gained from it is meaningless.

Question 94

How is the reliability assessed in an experiment?

Answer 94

Replication: this refers to repeating an experiment under exactly the same conditions. If the same results are obtained, then those results are seen as reliable.

Question 95

How is the reliability improved in an experiment?

Answer 95

Control of variables
Reducing Investigator effects
Standardisation of Instructions

Question 96

How is the reliability assessed in an observation?

Answer 96

Inter-researcher reliability: this is assessed by measuring the extent to which researchers scoring the same Ps achieve consistency of measurement between each other. Raters record their own data individually and then the sets of data from each scorer are correlated. High inter-rater reliability is indicated by significant positive correlations.

Question 97

How is reliability improved in an observation?

Answer 97

Observers should be trained thoroughly in the techniques being used.
Operational definitions of the key terms involved should be clear and fully understood by all the raters. A behavioural checklist could be used for this.
Discuss problem s and unusual cases.

Question 98

How is the reliability assessed in a test/questionnaire?

Answer 98

Test-retest method: this tests reliability of a test over time. The same Ps are given the same test/questionnaire on 2 separate occasions with no feedback after the first. Correlational tests are used to indicate reliability. A significant positive correlation indicates test-retest reliability.

Question 99

How is the reliability improved in a test/questionnaire?

Answer 99

Revising questions/test items that may be unclear/ambiguous.
Revising testing procedures.
Rephrasing instructions for clarity.

Question 100

What is the aim of science?

Answer 100

The aim of science is to produce a body of knowledge through conducting research. This research is then communicated through the use of scientific journals. Before this research is published, it must be subject to the process of peer review.

Question 101

What is peer review?

Answer 101

Peer review is the assessment of scientific work by others who are specialists in the same field to ensure that any research intended for publication is of high quality. It involves all aspects of the investigation being scrutinized by a small group of experts (peers) in the particular field. These experts should be objective, have no vested interest and unknown to the author or researcher.

Question 102

What are the aims of peer review?

Answer 102

1. To validate the quality and relevance of the research
2. To suggest amendments or improvements
3. To allocate research funding
4. To prevent the publication of fraudulent research.

Question 103

What is qualitative data?

Answer 103

Qualitative data – expressed in words, rather than numbers or statistics, and may take the form of a written description of the thoughts, feelings and opinions of participants (or a written account of what the researcher saw in the case of an observation). Thus, a transcript from an interview, questionnaire responses to an open question, an extract from a diary or an observer’s unstructured observation would yield qualitative data.

Question 104

What are the evaluating points of qualitative data?

Answer 104

+ Rich in detail, compared to quantitative.
+ Greater external validity than quantitative.
- Difficult to analyse and make comparisons.
- Conclusions often rely on the subjective interpretations of the researcher.

Question 105

How is qualitative data analysed?

Answer 105

• Context analysis - Categories of data and Counting frequency.
• Thematic analysis - Read transcripts, Identify themes and Write a report.

Question 106

What is quantitative data?

Answer 106

Quantitative data – expressed numerically. Quantitative data collection techniques usually gather numerical scores from a participant e.g. number of words recalled in an experiment.

Question 107

What are the evaluating points of quantitative data?

Answer 107

+ Easy to analyse and make comparisons.
+ Conclusions are objective - so results can’t be ministered.
- Not very rich in detail.
- Has little external validity compared to qualitative data.

Question 108

How is quantitative data analysed?

Answer 108

• Descriptive statistics - Mean, mode, median.
• Measure of dispersion - Range, standard diviation.
• Inferential statistics - Tests.

Question 109

What is primary data?

Answer 109

Primary data – refers to original data that has been collected specifically for the purpose of the investigation by the researcher. It is data that arrives first hand from the participants themselves.

Question 110

What are the evaluating points of primary data?

Answer 110

+ It fits the job – researchers can design their studies specifically, in order that they target the information the researcher requires.
- More time and effort is required, in comparison to secondary data.

Question 111

What is secondary data?

Answer 111

Secondary data – is data that has been collected by someone other than the person who is conducting the research. Secondary data includes data that may be located in journal articles, books or websites.

Question 112

What are the evaluating points of secondary data?

Answer 112

+ Less time and effort is required, in comparison to primary data.
- Doesn’t always fit its purpose – the research might not suit their study specifically.

Question 113

What is meta-analysis?

Answer 113

Meta-analysis – this is a particular research method that uses secondary data. It refers to a process where the data from a large number of studies, which have used the same research questions and methods, are combined. It is ‘research about research’. The researchers may perform a qualitative and/or quantitative analysis of the studies. It may involve calculating the ‘effect size’ which gives the overall statistical measure of difference or relationship between variables across a number of studies.

Question 114

What are the evaluating points of meta-analysis?

Answer 114

+ Greater confidence in the findings
+ Results can be generalised across much larger populations
- Prone to publication bias – the researcher may omit studies, especially those with negative or non-significant results.

Question 115

What is descriptive statistics?

Answer 115

Descriptive statistics is the term given to the analysis of data that helps describe, show or summarise data in a meaningful way such that, for example, patterns might emerge from the data.

Question 116

What are measures of central tendency?

Answer 116

Measures of central tendency give average scores in a set of data.

Question 117

What does the measures of central tendency involve?

Answer 117

Mean
Median
Mode

Question 118

What is the mean?

Answer 118

The middle value of a set of numbers that has been placed in numerical order.

Question 119

What are the advantages and disadvantages of the median?

Answer 119

+ It takes all the scores into account therefore all data is represented.
- When extreme scores are present the mean is not an accurate measuring tool. This is because the anomalies will distort the mean and make it unrepresentative.

Question 120

What is the median?

Answer 120

The middle value of a set of numbers that has been placed in numerical order.

Question 121

What are the advantages and disadvantages of the median?

Answer 121

+ It is unaffected by extreme scores. This means it is most appropriate measure when there is an anomaly.
- It does not take into account all of the scores and is therefore less sensible that the mean.

Question 122

What is the mode?

Answer 122

The value that occurs most frequently in any set of scores.

Question 123

What are the advantages and disadvantages of the mode?

Answer 123

+ It is unaffected by anomalies as by definition, there will be few of them.
- It tends to be unstable, as if there are only a few scores representing each value, then even very small changes in the data can radically affect the mode.

Question 124

What are measures of dispersion?

Answer 124

Measures of dispersion tell us how widely the data is spread.

Question 125

What does measures of dispersion involve?

Answer 125

Range

Standard Deviation

Question 126

What is the range?

Answer 126

The difference between the highest and the lowest score in any condition +1.

Question 127

What are the advantages and disadvantages of the range?

Answer 127

+ Easy and quick to calculate.

- Vulnerable to rogue scores i.e. a very high or low score - an anomaly.

Question 128

What is the standard deviation?

Answer 128

The mot frequently used measure of dispersion. It s the average amount all scores deviate from the mean.

Question 129

What are the advantages and disadvantages of standard deviation?

Answer 129

+ Gives a more accurate picture of the range.
+ Takes into account all of the scores and provides a sensitive measure of dispersion.
- Vulnerable to rogue scores i.e. a very high or low score.

Question 130

What are the three distinct types of data?

Answer 130

Nominal
Ordinal
Interval

Question 131

What is nominal data?

Answer 131

Data is allocated to categories that are mutually exclusive e.g. male/female or smoker/non-smoker.

Question 132

What is ordinal data?

Answer 132

Data allocated to categorises can be placed in a logical order based on their meaning, however the difference between the values are not the same. E.g. very confident, confident or not at all confident.

Question 133

What is interval data?

Answer 133

Data can be ordered and the intervals on a scale are equal as they are based on a standard unit of measurement. However, the point used to indicate 0 is arbitrary. E.g. IQ scores - it is not possible to claim that someone with an IQ of 120 is twice as intelligent as someone with an IQ of 60.

Question 134

What are the points of histograms?

Answer 134

• Can be used when presenting continuous data on interval or ratio scales of measurement.
• The scores are indicated on the horizontal (x) axis.
• The frequencies are shown on the vertical (y) axis.
• Consists of a series of vertical bars of equal width to represent each score or group of scores.
• The bars on a histogram actually touch.

Question 135

What are the points of bar charts?

Answer 135

• Can be used when the data are in categories (nominal or ordinal) or to illustrate the average scores from different samples.
• The categories are indicated on the horizontal (x) axis.
• The frequencies are shown on the vertical (y) axis.
• Each bar is separated so that a continuous variable is not implied.
• Bars can be presented in any order.

Question 136

What are the points of frequency polygon?

Answer 136

• This is a useful technique when it is necessary to compare two or more frequency distributions.
• Two or more conditions of an experiment can be presented at the same time.
• Can be used when presenting continuous data on interval or ratio scales of measurement.
• The scores are indicated on the horizontal (x) axis.
• The frequencies are shown on the vertical (y) axis.

Question 137

What are the points of scattergrams/scatter graph?

Answer 137

• Used to present correlational data.
• Data from one of the variables is presented on the horizontal (x) axis and data from the second variable is on the vertical (y) axis.

Question 138

What is normal distribution?

Answer 138

The normal distribution is a classic, bell shaped curve. Many human characteristics are normally distributed, such as intelligence and shoe size.

Question 139

What are the features of a normal distribution?

Answer 139

• Mean, median and mode are all in the exact same mid-point.
• The distribution is symmetrical around its mid-point.
• The dispersion of scores either side of the mid-point is consistent and can be expressed in SD’s.

Question 140

What are skewed distributions?

Answer 140

A distribution is negatively skewed, or skewed to the left, if the scores fall toward the higher side of the scale and there are very few low scores. In positively skewed distributions, the mean is usually greater than the median, which is always greater than the mode.

Question 141

What is statistical testing?

Answer 141

Statistical testing provides a way of determining whether hypotheses should be accepted or rejected.
In psychology, they tell us whether differences or relationships between variables are statistically significant or have occurred by chance.

Question 142

What is the sign test?

Answer 142

The sign test is a non-parametric statistical test of difference that allows a researcher to determine the significance of their investigation. It is used in studies that have used a repeated measure design, where the data collected in nominal.
Significance = research findings are sufficiently strong for us to reject the null hypothesis.

Question 143

What are the concept of probability?

Answer 143

All studies employ a significant level in order to check for significant differences. The accepted level of probability in psychology is 0.05 or 5%. This is the level at which the researcher decides to accept the research hypothesis or not.
If the experimental hypothesis is accepted, this means that there is 5% or less probability that the results occurred by chance. In simple terms, this means the researcher can be pretty certain (95%) that the difference found was because of the manipulations of the IV (though there will always be 5% doubt even if significance is found).
In some circumstances, researchers need to be even more confident that results were not due to chance and so employ a stricter, more significant level such as the 0.01 (the 1% level). This is in case where the research may involve a human cost, such as when new drugs are being trailed or where a particular investigation is a one-off and there is no possibility that it can be repeated in the future.

Question 144

What is the critical value in the sign test?

Answer 144

When the statistical test has been calculated the researcher is left with a number – the calculated value. This needs to be compared with a critical value to decide whether the result is significant or not. The critical values for a sign test are given in a table of critical values.

Question 145

What information is required to use the table of critical values?

Answer 145

• The significance level desired (always use 0.05 expect in circumstances described above).
• The number of participants in the investigation (The N value).
• Whether the hypothesis is directional (one-tailed) or non-directional (two-tailed).

Question 146

What are the 6 steps to calculate the significance of a study?

Answer 146

1. We need to take the result before away from the result after. For each calculation we then write in which sign we end up with (+ - 0).
2. Next we simply need to count up the amount of positives, negatives and zeros.
3. We then the lower number out of the sign (except the zero) and that will equal our ‘s’.
4. We then need an ‘N’ which is ‘number of participants’ and we need to minus the zero scores. N=11 minus the number of zero’s.
5. We then need to calculate the level of significance to see if there is a statistical difference in these two conditions. Remember that the level of significance in psychology is 0.05 and so basically we want to be 95% sure of our results and we only allow a 5% error rate. Using the significance table and the ‘N’ state to find the critical value.
6. Now finally we need to see if this ‘critical value’ is significant. Remember the rule is: The Calculated value of ‘s’ must be equal to or less than the critical value in this table for significance to be shown.