Research methods



AS PSYCHOLOGY

UNIT TWO

Research methods

Revision booklet

All you need to know for the exam

|Deciding on a research question |

|Knowledge and understanding of: |

|( aim of the research |

|( research hypotheses |

|( alternative (or experimental) hypotheses |

|( directional and non-directional hypotheses |

|( null hypotheses |

|( independent variables |

|( dependant variables |

|( co-variables |

|( operationalisation of variables |

|( confounding variables |

|extraneous variables |

|Methodologies Knowledge, |

|Understanding and evaluation of: |

|( experiments |

|( quasi-experiments (including natural experiments) |

|( participant observations |

|( non-participant observations |

|( content analysis ( structured interviews / questionnaires |

|( semi-structured interviews |

|( correlational studies |

|( case studies |

|( self-reports |

|quantitative data and qualitative data should be included. Both primary and secondary sources should be included |

|Location of research |

|Knowledge, understanding and evaluation of: |

|( conducting research in a laboratory environment |

|( conducting research in the field |

|( conducting research on-line |

|Participants |

|Knowledge, understanding and evaluation of: |

|( target populations |

|( sampling frames |

|( random sampling |

|( opportunity sampling |

|( systematic sampling |

|( stratified sampling |

|( quota sampling |

|( self-selected sampling |

|( snowball sampling |

|( observational sampling techniques (including event sampling, time sampling) |

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Designing psychological investigations

An aim is a statement of the purpose of a study.

Hypothesis is a statement that is testable. A research hypothesis is a general prediction made at the beginning of an investigation, about what the researcher expects to happen.

Types of hypotheses

➢ Experimental hypothesis/alternative hypothesis predicts that something other than chance alone has played a part in producing the results obtained.

➢ Null hypothesis predicts that the results obtained from an investigation are due to chance alone.

A directional hypothesis predicts the direction in which results are expected to occur. E.g. of a directional hypothesis. More words are recalled from a list when using rehearsal as mnemonic technique than when no mnemonic technique is used.

A non-directional hypothesis does not predict the expected direction of outcome. E.g. of a non-directional hypothesis. There is a difference in the number of words recalled from word lists presented with or without the presence of background music.

Experimental method

• Manipulates an independent variable (IV) in order to investigate the change in dependent variable.

• All other variables which might influence the results (called extraneous variables) are controlled.

• Participants are randomly allocated to the experimental and control conditions.

IV: Variable that is deliberately manipulated by the experimenter and is assumed to have a direct effect on the dependent variable.

DV: Variable that is measured

Extraneous variable- you are not intentionally studying in your experiment or test. When you run an experiment, you’re looking to see if one variable (the independent variable) has an effect on another variable (the dependent variable) Other variables, perhaps ones that never crossed your mind, might influence the outcome of an experiment. These undesirable variables are called extraneous variables.

Confounding variables- varies systematically with the IV that might potentially affect the DV and confound the results e.g. age

*The difference…. There are two types of variables that can lower internal validity: extraneous variables, which are any factors that are in the experiment but not being studied, and confounding variables, which are related to the independent variable and affect the dependent variable.

Operationalisation – Making variables measurable and testable

Experimental designs

Repeated measures – the same PP’s are tested in all conditions, this means there is no individual differences and uses less PP’s which means consistent results. However there can be order effects as PP’s know what is coming. – control used is counterbalancing

Independent groups design – different PP’s are used in each of the conditions, the PP’s are usually randomly allocated to each condition to try and balance any differences. There are no order effects in this instance, there are no demand characteristics but there are group differences.

Matched pairs design – different but similar PP’s are used in each of these conditions, the PP’s are matched to another PP in other groups, identical twins are the perfect matched pair. There are less group differences than in independent design, but matching is difficult and time consuming.

Quasi Experiments

Natural experiments: Take advantage of a naturally-occurring change in behaviour. By measuring before and after the change, the experimenter hopes to find out what affect the change had. An example of a natural experiment might be a study that looks at the effects on aggressive behaviour of the introduction of TV for the first time into a previously isolated community. Do not confuse natural experiments with naturalistic observation.

Differences studies: IV is natural and the DV maybe measured in a lab. The IV has not been varied by anyone, it is simply a difference that exists- not a variable at all. Eg Gender differences

|Advantages |Disadvantages |

|Behaviour is observed in natural surroundings. |There is no control over other changes that might happen. |

|Samples are usually large and representative. |Measure may be not as accurate as direct observation because of the presence of the |

| |experimenter. |

Non-experimental methods

Questionnaires: are used to obtain views of large numbers of people about specific issues or topics.

The questions on a questionnaire can be either ‘closed’ or ‘open’. Closed questions provide people with a fixed set of responses, whereas open questions allow people to express what they think in their own words.

The responses to closed questions are easy to summarise and quantify whereas the responses to open questions are much more difficult to analyse. But in some ways the rich detail provided by open questions can provide useful insights into the topics being researched.

|Advantages |Disadvantages |

|Large amounts of data can be collected very easily and quickly |Rely on self-report data which may be biased |

|Questionnaires using closed questions are highly replicable. |Data may be biased by response rates |

|Open ended questions can provide rich detail |Social desirability effects may influence responses |

Interviews: There are two types of interviews – structured and semi-structured.

In structured interviews each participant is asked the same questions in the same order. Many of the questions will have a fixed set of responses that the participant has to choose from.

|Advantages |Disadvantages |

|Data can be summarised and analysed quite quickly |Any interesting issues raised by participants cannot be followed up |

|It is possible to interview large numbers of people fairly efficiently | |

Semi-structured interviews - combination of fixed questions and open-ended questions where participants are given the opportunity to talk about particular topics.

Unstructured interview - no fixed questions at all.

|Advantages |Disadvantages |

|Generates huge amounts of data which enables interesting topics to be explored |Analysis can be very time consuming |

|in great depth | |

|Useful when dealing with complex issues such as bereavement, violence and |Replicating the research can be difficult |

|parenting | |

Observational studies: covert observation and overt observation.

In participant observation the researcher becomes part of the group they are studying and takes part in the group’s activities as well as recording the behaviour of the group.

In non-participant observation the researcher is separate from those being observed and records the behaviour but does not take part in any of the activities.

← Researcher must define the behaviour he/she observes.

← Psychologists use behavioural categories to record particular instances of behaviour.

← For example, observers may use check lists or tally chart for recording observations.

← Sampling techniques used for observation can be time sampling and event sampling.

|Advantages |Disadvantages |

|Participants are behaving naturally in an everyday |One of the main ethical issues is consent. Participants should normally be aware that they are|

|environment. This means that the studies have high ecological|taking part in a study and have the right to withdraw. However, there is the problem that if |

|validity. |participants know they are being observed they may change their behaviour. |

|This means that the studies have high ecological validity. |Observational studies also tend to focus on ‘whole behaviours’ rather than breaking behaviour |

| |down into small units |

Case study

This is an in-depth study of one individual or a small group of people. Case studies are often carried out on those who are of special interest because they are outstanding or different in some way.

|Advantages |Disadvantages |

|The case can be viewed in depth and long sequences of behaviour can be |Results cannot be generalised as they may not be representative of the |

|followed |general population. |

|It is not artificial as it relates to an individual or small group’s |Sometimes, case studies are carried out retrospectively and the evidence may |

|experiences. |become distorted in people’s memories. |

|Rich qualitative data can be collected |Replication is difficult |

Content analysis

Involves observing people via artefacts they produce. Content analysis involves sampling method (e.g. material to sample & how frequently) and behavioural categories to be used.

|Advantages |Disadvantages |

|They have high ecological validity as based on e.g. observations|Observer bias could arise as the researcher carrying out the |

|of what people really do / real communications such as newspaper|content analysis may interpret the meaning of different |

|articles. |categories differently to another researcher |

| | |

|They can be replicated if the sources (diary/ newspaper / | |

|videos) are retained | |

Location of research

Laboratory

Participants are put under different conditions and then their performance is measured. The laboratory is a convenient setting for the experimental method because the experimenter can then control what happens.

|Advantages |Disadvantages |

|The experimenter can control the experiences of the participants. It is |The laboratory is an artificial situation. Participants may act differently |

|possible to isolate cause and effect relationships more precisely. |from the way they would in real life. |

|Equipment can be ready and available for measuring the participants’ |Tasks may have little relevance to real life. |

|behaviour. | |

Field

Investigations carried out in natural settings (e.g. homes, school).

|Advantages |Disadvantages |

|Reduced demand characteristics |Degree of control over IV is less than lab |

|Higher in ecological validity than lab experiments though still has control |More difficult to control extraneous variables |

|over IV | |

Online

Often involves questionnaires can be over internet of use social networking sites

|Advantages |Disadvantages |

|Large Ps accessible and it is cost effective |Consent is hard to gain |

|Usually uses questionnaires so the use of closed questions- |Social desirability bias |

|replicable. | |

Sampling techniques

• Random sampling, Every member of the target population has an equal chance of being selected, e.g. selected by computer from the electoral roll. Unbiased, though may not be representative / problems with generalisation

• Opportunity sampling, Use whoever is immediately available e.g. go out and accost passers-by. Biased sample / not be representative / problems with generalisation

• Volunteer sampling, use whoever puts themselves forward e.g. advertise in the paper. Biased sample / not representative. / problems with generalisation

Reliability

Internal Reliability: The consistency of a measure within a test (i.e. all items need to be measuring the same thing).

External Reliability: The ability to replicate the results of a study and get the same or highly similar results.

In the context of an experimental research it refers to consistency of results.

• In observation method, the extent of agreement between observers is called inter-rater or inter-observer reliability. Reliability can be improved through training.

• In self report methods, the two types of reliabilities are

Inter-interviewer reliability- is the consistency of the outcome of interviews by different interviewers.

• Two assessment methods of reliability: Split-half method and test-retest method.

Validity –whether the results obtained in a study are true/genuine.

Internal validity: Whether the study did test, what it intended to measure e.g. Face validity: the extent to which the test looks as if it is measuring what it should measure. Concurrent validity: assessed by comparing the outcome of a test with an already established test on the same topic.

External validity: the extent to which the results of the study can be generalised to other situations and people e.g. ecological validity, population validity, historical validity.

Assessing and Improving Reliability and Validity:

|Assessing Reliability: |Assessing Validity: |

|Internal: Assessed using the split-half method. This is when one half of the |Internal: Running a pilot study allows researcher to identify whether there |

|test is compared with the other in order to check whether the scores are |are any issues with the study (e.g. confusing items on the questionnaire). |

|consistent. |The researcher would also operationalise all variables. |

|External: Assessed using the test-retest method. The test is carried out on |External: The researcher could test the findings from one study in a number |

|the same of similar PPs several times and the similarity of results is |of different settings and with different PPs. This would allow the |

|recorded. Alternatively, a correlation coefficient can be worked out between |researcher to see whether or not their results can be applied to the entire |

|two sets of scores. The higher the correlation coefficient, the higher the |population or to what extent they are limited. |

|reliability! | |

Variables can be controlled by

• Counterbalancing

• Random allocation

Extraneous variables can be controlled by keeping them constant or eliminating them altogether.

All the variables other than the independent variable that might affect the dependent variable are called extraneous variables. If a variable other than the IV, produces a change in a DV, the results of the study are said to have been confounded.

Demand Characteristics: The features of an experiment that inform participants about the aim and influence their behaviour. Could be a confounding variable

Investigator effects: anything the investigatior/experimenter does which has an effect on the participant’s performance or behaviour. Could be a confounding variable

Pilot Study – is a preliminary study or trial often carried out to predict snags and find out about the main features of a main research study that will follow it. A trial-run basically. Piloting is trying out the scale or research design on a small sample.

Ethical considerations

Valid Consent, Deception, Confidentiality, Privacy, Risk of Harm

Ways of dealing with ethical issues:

- Anonymity

- Right to withdraw

- Debriefing

- Consulting an ethics committee

- Cost-benefit analysis

Data Analysis

Analysis and interpretation of quantitative data.

|Bar chart: used when data is in |Histogram: Used for continuous data from |Scattergram: Used for correlation to |Line graph: Used for continuous data, to |

|discrete categories. The bars should |one data set. Used for ordinal, interval |show relationship between two |compare 2 data sets. Used for ordinal, |

|not touch. Can be used for mean |ratio data |variables. |interval ratio data |

|scores. | | | |

Tables of results

Table to show the mean and SD for words and pictures

| |Words |Pictures |

|Mean |6 |9 |

|SD |2.3 |1.9 |

Frequency table to show the differences between males and females in physical and verbal aggressive acts observed in TV soaps

| |Males |Females |

|Physical |35 |7 |

|Verbal |12 |26 |

Measures of central tendency:

Mode: A measure of central tendency that represents the most occurring value in a set of scores. Used for nominal data

Median: The measure of central tendency that represents the value of the middle score. Is not effected by extreme scores, however does not take into consideration all values. Used for ordinal data.

Mean: A measure of central tendency where you add up all of the scores and divide by the number of scores you have. Takes into consideration all values but is effected by extreme scores. Used for interval data

Measures of dispersion.

Range: The spread of scores from the highest score to the lowest. Used with the median

Standard Deviation: The measure of dispersion that shows how far away the scores are from the mean.

Levels of measurement

Nominal: Data in categories

Ordinal: Data that is ordered e.g. rating scales

Interval: Data using units of equal measurements

Ratio: Data that has a true zero point

Test your knowledge

For each of the methods of investigation explain each and provide two advantages and disadvantages Laboratory Experiments, Field Experiments and natural Experiments

Identify and explain the six of the ethics that all Psychologists need to abide by:

What does the acronym DIP stand for and how can you use it in your exam answers?

Identify the three types of graphs that you can use and explain under what conditions you would use them?

Explain how to calculate the following and describe their purpose within investigations Mean, Mode, Median and Range

What does a high standard deviation show?

What does a low standard deviation show?

What is the difference between these two Quantitative and Qualitative Data?

What is content analysis?

What is a hypothesis?

What are the two types of hypothesis and what is the difference between them?

What is the difference between a directional and a non-directional hypothesis?

What is an independent variable?

What is a dependant variable?

What is an extraneous variable?

Explain the four types of extraneous variable

What does it mean to operationalise a variable?

Define reliability

Define validity

What is the difference between internal and external validity?

Why would an experimenter use standardised procedures?

How can validity be measured?

What is meant by the Target Population?

Explain Random Sampling

Explain Opportunity Sampling

Explain Volunteer Sampling

What is the advantage and disadvantage of Repeated Measures design

What is the advantage and disadvantage of Independent Measures design

What is the advantage and disadvantage of match Pairs design

Why would an experimenter use standardised instructions?

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