Aim
A general statement about what the researcher intends to investigate; the purpose of the study
Hypothesis
A clear, precise, testable statement that states the relationship between variables to be investigated
Directional hypothesis
States the direction of the difference or relationships
Non-directional hypothesis
Does not state the direction of the difference or relationship
Variables
Any 'thing' that can very or change in an investigation
Independent variable
Some aspect of the experimental situation that is manipulated by the researcher or changes naturally
Dependent variable
The variable that is measured by the researcher
Extraneous variable
Any variable other than the IV that may have an effect on the DV if not controlled
Operationalisation
Clearly defining variables in terms of how they can be measured
Confounding variable
Any variable other than the IV that will have affected the DV
Randomization
The use of change in order to control for bias in experiments
Investigator effects
Any effect of the investigator's behaviour on the research
Demand characteristics
Any cue that may be interpreted by participants as revealing the purpose of the investigation
Standardisation
Using exactly the same procedures and instructions for all participants in a research study
Experimental design
The different ways in which the testing of participants can be organized in relation to the experimental conditions
Independent groups design
Participants are allocated to different groups where each groups represents one experimental condition
Repeated measures
All participants take part in all conditions of the experiment
Matched pairs design
Pairs of participants are first matched on some variable then placed in alternative conditions
Counterbalancing
Half the participants experience the conditions in one order (A then B) and the other half the opposite order (B then A)
Lab experiment
Takes place in a controlled environment where the researcher manipulates the IV and controls EVs
Field experiment
Takes place in a natural setting where the researcher manipulates the IV
Natural experiment
The change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there
Quasi experiment
The IV has not be determined by anyone -the variable simply exist e.g. age (not technically an experiment)
Population
A group of people who are the focus of the study
Sample
A group of people who take part in the study
Generalisation
The extent to which the findings and conclusions can be applied to the population
Random sampling
Every member of the target population has an equal chance of being selected
Systematic sampling
Every 'nth' member of the target population is selected
Stratified sampling
The sample reflects the proportions of people in the sub-groups (strata) within the target population
Opportunity sampling
Anyone who is willing and available to participate
Volunteer sampling
Participants select themselves to be part of the sample
Correlation
A technique in which a researcher investigates an association between 2 variables, called co-variables
Qualitative data
Data that is expressed in words and non-numerical
Quantitative data
Data that can be counted, usually given as numbers
Primary data
Information that has been obtained first-hand by the researcher for the purposes of a research project
Secondary data
Information that has already been collected by someone else and so pre-dates the current research project.
Meta-analysis
Research about research -combining results from a number of studies on a topic to provide an overall view
Pilot study
A small scale version of an investigation that takes place before the real investigation is conducted.
Naturalistic observation
Watching and recording behaviour in a natural setting
Controlled observation
Watching and recording behaviour in a structured setting
Covert observation
Participants behaviour is watched and recorded without their knowledge or consent
Overt observation
Participants behaviour is watched and recorded with their knowledge and consent
Participant observation
The researcher becomes a member of the group
Non-participant observation
The researcher remains outside of the group
Behavioural categories
When a target behaviour is broken up into components that are observable and measurable
Event sampling
The researcher records every time a behaviour/event occurs
Time sampling
The researcher records behaviour in a fixed time frame
Measures of central tendency
The term for any measure of the average value in a set of data (mean, mode and median)
Measures of dispersion
The term for any measure of spread or variation in a data set (range and standard deviation)
Standard deviation
Tells us how much score deviate from the mean by calculating difference between mean and each score.
Normal distribution
A symmetrical spread of frequency data that forms a bell-shaped pattern.
Skewed distribution
A spread of frequency data that is not symmetrical, where the data clusters to one end.
Positive skew
Type of distribution -long tail is on the positive (right) side of peak and most of the distribution is concentrated on the left.
Negative skew
Type of distribution -long tail is on the negative (left) side of peak and most of the distribution is concentrated on the right
Sign test
A statistical test used to analysethe difference in scores between related items. Data should be nominal
Content analysis
A technique that enables the indirect study of behaviour by examining communications that people produce.
Coding
Stage of content analysis where communication is analysed by identifying each instance of the chosen categories
Thematic analysis
A qualitative approach that involves identifying implicit or explicit ideas within the data. Themes often emerge.
Face validity
A form of validity in which a measure is scrutinized to determine whether it measures what it's supposed to
Concurrent validity
The extent to which a psychological measure relates to an existing similar measure.
Ecological validity
The extent to which findings from a research study can be generalized to other settings and situations
Temporal validity
The extent to which findings can be generalized to other historical times and eras
Levels of measurement
Quantitative data can be classified into levels of measurement: nominal, ordinal and interval.
Probability
A measure of the likelihood that a particular event will occur where 0 indicates statistical impossibility.
Significance
A statistical term that tells us how sure we are that a difference or correlation exists.
Critical value
When testing a hypothesis,the numerical cut-off point between acceptance and rejection of the hypothesis.
Type 1 error
Incorrect rejection of a true null hypothesis (false positive)
Type 2 error
Failure to reject a false null hypothesis (false negative)
Paradigm
A set of shared assumptions and agreed methods within a scientific discipline
Paradigm Shift
The result of scientific evolution - a significant change in the dominant theory