Non-directional
A hypothesis which states that there is a difference but not what the difference will be.
Directional
A hypothesis which states the direction of the difference or relationship.
Null
A hypothesis which states the study will find no difference between IV and DV.
IV
The variable of the study/experiment which is changed.
DV
The variable which is measured.
Pilot
A small study carried out before the bigger study.
Confederate
A person who participates in a study, but is not measured.
Extraneous
In an experiment, a variable other than the IV that might cause unwanted changes in the DV. Effects all participants, such as lighting.
Confounding
A variable other than the IV that causes changes to the DV; usually found after a study.
Situational
Variables where environmental factors may cause issues with participants.
Standardised procedures
A set of procedures that are the same for all participants in order to combat situational variables.
Experimenter
Variables where the presence of the experimenter may cause problems with participants, such as their gender, age, race or accent.
Double-blind
A technique where the person conducting the experiment doesn't know the aims, same as the participants.
Participant
A variable where characteristics such as age, gender, and intelligence that vary from one individual to another and may affect the results.
Matched pairs
An experimental design where subjects are first matched by a characteristic and then assigned into different groups.
Repeated measures
An experimental design where the same participants are used in all the conditions in an experiment.
Demand characteristics
Cues in an experiment that tell the participant what behavior is expected.
Target population
The total group to be studied or described and from whom samples may be drawn.
Generalisable
The results from the sample can be applied to the target population.
Random
A method of sampling that gives each person in a group the same chance of being selected.
Systematic
A method of sampling where every nth item in the target population is selected.
Opportunity
A method of sampling where anyone who can be asked is asked.
Volunteer
A method of sampling where participants are invited to take part.
Stratified
A sampling method that is variation of random sampling; the population is divided into subgroups and weighted based on demographic characteristics of the national population.
WEIRD
Western, Educated, Industrialized, Rich and Democratic.
Snowball
A method of sampling that recruits via referrals from one participant to others.
Reliability
Ability of a test to yield very similar scores for the same individual over repeated testings.
Internal validity
Extent to which the IV effects DV; with no issues from EVs.
External validity
Extent to which we can generalize findings across populations, areas and times.
Mundane realism
The extent to which an experiment is similar to real-life situations.
Control
How consistent the study remains over IV changes; participants, environment, etc.
Primary
Data that is collected firsthand by the researcher and are specifically designed. They can be lengthy or expensive, but have total control.
Secondary
Data that is collected from already available research, so struggles to fit the needs of research. Quick and easy.
Quantitative
Data that is numerical, and can be divided into different forms.
Qualitative
Data that is word based, such as interviews and articles.
Nominal
Data is organised into named categories, such as 'yes' and 'no'. Measures frequencies, lowest level of measurement.
Ordinal
Ranked data, such as a happiness scale. Middle level of measurement.
Outlying data
Anomalous data, skews the data and increases standard deviation.
Central tendency
Measures that calculate an average; mean, mode and median.
Dispersion
Measures that show how representative the mean is; range and standard deviation.
Standard deviation
Sum that quantifies the amount of dispersion of the values in a data set; shows how accurate the mean is.
Interval
Data that uses numerical measurements with equal distances between them. Highest level of measurement, can go into negatives.
Ratio
Data that uses numerical measurements with equal distances between them. Highest level of measurement, cannot go into negatives.
Correlational
Studies that aim to show a correlation.
Correlation coefficient
A scale from 1- - 1 that rates the strength of the correlation.
Case study
A non-experimental method that entails an in-depth examination of a person, institution or community using many different investigation methods.
Co-variables
Replacement for IV and DV in non-experimental studies.
Longitudinal
Studies that take place over a long period of time, often case studies.
Attrition
People dropping out a study for various reasons.
Cohort
Type of effects where generational experiences make the study un-generalisable across generations.
Self report
Techniques where a person describes their own opinions and emotions.
Questionnaire
Written questions with written answers.
Interview
Verbal questions with verbal answers.
Closed
Questionnaire questions with set answers to be selected from.
Unstructured
An interview that allows for unplanned questions, which can have a small set list or be completely random.
Validity
Whether the observed effect is genuine, whether it measures what it's supposed to and can be generalised.
Order
Effects where participant fatigue or boredom due to repeating a study, occurs during a repeated measures design.
Counterbalancing
How to overcome order effects, using and AB or BA method, or the ABBA method.
ABBA
Type of counterbalancing where participants complete all conditions twice.
AB
Type of counterconditioning where groups are split into two, with one doing condition A first and then B, and the other doing the reverse.
Social desirability
Bias that causes participants to give a more socially acceptable answer.
Lab
Experiments that occur in a controlled environment.
Field
Experiments that occur in natural environments.
Online
Research that occurs via the internet.
Quasi
Experiments where the IV is not manipulated for ethical or plausibility reasons.
Content analysis
Analysis of already existing content, such as advertisements and books.
Behavioural categories
Breaks down content into quantitative data, done in quantitative analysis.
Cross-sectional
Non-experimental studies that compare two or more groups of people with a difference, such as young and old people.
Debrief
An interview after a study/experiment to check a person’s welfare and allow a person to withdraw their data.
Presumptive
Consent that is assumed from asking a similar group.
Retrospective
Consent given after a study.
Observation
A type of non-experimental research where behaviour is observed.
Event sampling
Type of observation where the frequency of behaviours within one time frame is counted.
Time sampling
Type of observation where the frequency of behaviours across multiple time frames is counted.
Overt
Type of observation where the participants have given informed consent to be observed.
Covert
Type of observation where the participants are observed in secret.
Intervening
The third variable in correlation studies that may have caused the correlations.
Confounding
Type of variable that affects individual participants, such as mood.