research methods

sign test

sign test

nominal data, related design, difference

wilcoxon test

ordinal data, related design, difference

related t test

interval data, related design, difference

chi-squared

nominal data, unrelated design, difference

nominal data, correlation

mann whitney

ordinal data, unrelated design, difference

unrelated t test

interval data, unrelated design, difference

spearmans rho

ordinal data, correlation

pearsons rho

interval data, correlation

0.05 level of significance

5% due to chance

95% due to researchers manipulation

prevents type 1 or type 2 error

0.01 level of significance

1% due to chance

99% due to researchers manipulation

causes type 2 error

0.10 level of significance

10% due to chance

90% due to researchers manipulation

causes type 1 error

Variable

Any 'thing' that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing results in changes in another.

Independent variable

The aspect of the experimental situation that is manipulated by the researcher (or changes naturally) so the effect on the DV

Dependent variable

Measured by the researcher. Any effect on the DV should be caused by the change in the IV.

Aim

A general statement of what the researcher intends to investigate; it is the purpose of the study

Hypothesis

A clear, precise, testable statement that states the relationship between the variables to be investigated, and it is stated at the outset of any study

null hypothesis

states there is no difference or relationship between the variables being studied

Directional hypothesis

States the direction of the difference or relationship. Psychologists tend to use a directional hypothesis when the findings of previous research suggest a particular outcome.

Non-directional hypothesis

Does not state the direction of the difference or relationship. Psychologists tend to use a non-directional hypothesis when there is no previous research, or findings from earlier studies are contradictory.

Demand characteristics

Any cue from the researcher or the situation that may be interpreted by the participants as revealing the purpose of the investigation.

Investigator effects

Any effect of the investigator's behaviour (conscious or unconscious) on the (dv) research outcome.

Ethical issues:

These arise when a conflict exists between participants' rights and researchers' needs to gain valuable and meaningful findings

Cost-benefit analysis

The role of ethics committees to make judgements about the costs and benefits involved in carrying out individual pieces of research

descriptive statistics

a way of analysing quantitative data through the use of graphs, tables and summary statistics to identify trends and draw meaningful conclusions

measures of central tendancy

Give us information about the most typical values in a set of data - mean, median, mode

measures of dispersion

Looks at the spread of values, i.e. how far values vary and differ from one another - range, standard deviation

order effects

when the positioning or order of the conditions influences the outcome

Randomisation

The use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions. It is one of the ways to minimise the effect of extraneous or confounding variables on the outcome (controlling for investigator effects)

Standardisation

When exactly the same formalised procedures and instructions are used for all participants in a research study. This ensures all participants are subject to the same environment, information and experience (controlling for investigator effects)

Levels (of the IV)

Different experimental conditions, chosen by the researcher, in order to test the effect of the IV.

Operalisation

When the researcher clearly defines the variables in terms of how they can be measured.

Inter-rater Reliability

the extent to which there is an agreement with two or more observers

test-retest reliability

a method for determining the reliability of a questionnaire or psychological test by assessing the same person on 2 separate occassions (sufficient time needed within the two)

reliability

the consistency of a research or measuring test

Extraneous variables

Variables other than the IV that may affect the DV

participant variables

Any individual differences between participants that may affect the DV

situational variables

Any features of the experimental situation that may affect the DV

Confounding variables

Any variables, other than the IV, that may have affected the DV so we cannot be sure of the true source of changes to the DV.

Participant reactivity

Participants are not passive within experiments and are likely to try and work out what is going on; this is a significant extraneous variable and is very difficult to control.

control condition

the condition that is not exposed to the variable that is changed

experimental condition

the condition that involves exposing the participants to change

Experimental design

The different ways in which the testing of participants can be organised in relation to the experimental conditions. The three types of experimental design are: independent groups, repeated measures and matched pairs.

Independent groups design

Participants are allocated to different groups where each group represents one experimental condition (levels of the IV)

Repeated measures design

All participants take part in all conditions of the experiment

experiment

an investigation where there is manipulation of the independent variable while other variables are tried to be kept constant. Allows a cause and effect relationship to be established

Laboratory Experiments

Take place in HIGHLY CONTROLLED ENVIRONMENTS. Doesn't necessarily have to be a 'laboratory', just has to be highly controlled. Researcher manipulates the IV and records the effect on the DV.

Field Experiment

Takes place in a natural, more everyday setting. Not literally in a field, in the field. Researcher manipulates the IV and records the effect on the DV.

Natural Experiment

Environment is natural as in field experiments, but also the change in the independent variable is also natural. The IV is not brought about by the researcher; it would have happened even if the researcher was not there.

Quasi Experiment

The IV is based on an existing/natural difference between people (e.g. age, gender, a disorder). No-one manipulates the IV, it just exists. You can't randomly allocate to conditions.

Counterbalancing

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. Each condition is tested first or second in equal amounts.

Matched pairs design

Pairs of participants are first matched on some key variable(s) that may affect the DV. One member of each pair is assigned to condition A, and the other to condition B. The data for each matched pair's performance is compared.

validity

the extent to which a test measures what they claim to measure

Internal validity

The degree to which the data and conclusions are considered to reflect the participants or phenomenon's reality

External validity

The extent to which the results and conclusions of a study can be generalised to other settings, populations and times

Informed consent

Involves making participants aware of the aims of the research, the procedure, their rights (including the right to withdraw) and what their data will be used for

Deception

Deliberately misleading or withholding information from participants at any stage of the investigation

Privacy

Participants have the right to control information about themselves

Confidentiality

Our right, enshrined in law under the Data Protection Act, to have any data protected Participants should have the right to control information about themselves but if that's not possible, confidentiality should be maintained.

protection from harm

Participants should leave the experiment in the same state they entered. They should not be subjected to physical or psychological harm, including embarrassment, stress or being placed under pressure.

Debrief

Where participants are made aware of the true aims of the investigation and any other details they were not supplied with during the study

Population

The group of people from whom the sample is drawn

Target population

The group of people that the researcher is aiming to investigate

sample

a group of people who take part in a research investigation - ideally representative of the target population

Opportunity sampling

Consists of taking the sample from people who are available at the time the study is carried out, and fit the criteria you are looking for

Random sampling

A sample in which every member of the target population has an equal chance of being chosen; this involves identifying everyone in the target population and then selecting the number of participants you need in a way that gives everyone in the population an equal chance of being picked

Stratified sampling

Involves classifying the population into categories and then choosing a sample which consists of participants from each category in the same proportions as they are in the target population

Self-selecting / volunteer sampling

Consists of participants becoming part of a study because they volunteered when asked (or in response to an advert)

Systematic sampling

Involves selecting every nth person from the target population, using a predetermined system to select participants

Naturalistic observation

Watching and recording behaviour in the setting within which it would normally occur; all aspects of the environment are free to vary

Controlled observation

Watching and recording behaviour within a structured environment, some variables are managed. There is some control over variables to observe effects and also control over extraneous variables

Covert observation

Participants' behaviour is watched and recorded without their knowledge or consent; participants are unaware they are the focus of a study

Overt observation

Participants' behaviour is watched and recorded with their knowledge and consent; informed consent has been obtained beforehand

Participant observations

The researcher becomes a member of the group whose behaviour they are for watching and recording

Non-participant observations

The researcher remains outside of the group whose behaviour they are watching and recording; this allows the researcher to record behaviour in a more objective manner

Unstructured observation

The observer write down everything they see, producing detailed qualitative data

Structured observation

The observer simplifies the target behaviour by specifying which particular aspects they will be looking for, producing quantitative data

Event sampling

Involves counting the number of times a particular behaviour occurs

Time sampling

Involves recording behaviour within a pre-established time frame

Self-report technique

Any method in which a person is asked to state or explain their own feelings, opinions, behaviours and/or experiences related to a given topic

Questionnaire

A set of written questions used to assess a person's thoughts and/or experiences

Interview

A 'live' encounter (face-to-face or on the phone) where the interviewer asks a set of questions to assess an interviewee's thoughts and/or experiences. The questions may be pre-set (as in a structured interview) or may develop as the interview goes along (unstructured interview)

Open questions

Questions for which there is no fixed choice of response and respondents can answer in any way they wish

Closed questions

Questions for which there is a fixed choice of responses determined by the question setter

Qualitative data

When data is expressed in words and may take the form of a written description of the thoughts, feelings and opinions of participants

Quantitative data

When data is expressed numerically, i.e. in numbers or quantities. This data is open to being statistically analysed and can be converted into graphs, charts etc.

Primary data

Information that has been obtained first hand by the researcher for the purposes of a research project, often gathered directly from participants

Secondary data

Information that has already been collected by someone else, and so pre-dates the current research project. Such data might include the work of other psychologists or government statistics

Meta-analysis

Refers to the process of combining results from a number of studies to make an overall analysis of trends and patterns.

Pilot study

A small scale 'trial-run' of the actual investigation, carried out before the full-scale research project begins (based on a small scale)

Single-blind procedures

Participants may not be told the aim of the experiment (or which condition they are in or whether there is another condition)

Double-blind procedures

Neither the participants nor the researcher who conducts the study is aware of the aims of the experiment. They are an important feature of drug trials

Correlation

Indicates the strength and direction of an association between two or more co-variables (not trying to show cause-and-effect, as there is no manipulation of one variable)

correlational hypothesis

Still has to clearly state the relationship between variables and can be directional or non-directional

There is no IV and DV but the co-variables have to be clearly operationalised

Correlation coefficient ('r'):

A number produced between -1 and +1 after statistical analysis of a correlation. This number represents the direction and strength of a relationship between co-variables.

anomaly

Something that deviates from the normal

Deduction:

The process of deriving new hypotheses from an existing theory

Co-variables

The 'things' that are being measured

alternative hypothesis

a testable statement about the relationship (difference or association) between two or more variables (directional or non directional)

Probability

A numerical measure of the likelihood or chance that certain events will occur. A statistical test gives the probability that a particular set of data did not occur by chance.

Critical value

The numerical boundary or cut-off point between acceptance and rejection of the null hypothesis