Definitions

• Independent variable 


  The variable the psychologist manipulates.
• Dependent variable 


  The variable the psychologist measures.
• Co-variables 


  Co-variables indicate 2 or more quantities being measured in a correlation by the researcher that may or may not vary with each other.
• Operationalisation of variables 


  Giving a precise definition of the behaviour being manipulated / observed / measured (IV / DV). This allows for repetition and raises reliability as it is an agreed value that has been attributed to the measurement.
• Confounding variables 


  Variables in a study that are not being manipulated by the researcher, that affect some participants behaviours but not others, having negative consequences for validity.
• Aim of research


  A broad statement of the purpose of the research.
• Alternative hypothesis


  A testable statement that a piece of research attempts to support or reject.
• Directional hypothesis 


  A hypothesis that suggests there will be a difference / relationship between variables, where the IV will effect the DV in one specific direction / outcome.
• Non-directional hypothesis


  A hypothesis that suggests that there will be a difference / relationship between the variables, but does not state a specific direction / outcome for results.
• Null hypothesis 


  A hypothesis that suggests that there will be no difference / relationship between variables, any that does occur does so by chance.
• Experiment


  A research method where cause and effect is measured, through the control and manipulation of key variables, and where the participants are randomly allocated to experimental / control group.
• Quasi experiments 


  A research where the experimenter has not deliberately manipulated the IV and participants are not randomly allocated. Methods within this category include natural experiments and difference studies.
• Natural experiments 


  A research method where the IV arises naturally, although the DV can still be measured in a lab or any other location of the researchers choice. This method would be used when it is unethical to directly manipulate the IV.
• Participant observations 


  A research method where the researcher takes on the role of a participant whilst observing other participants behaviour around them.
• Non-participant observation 


  A research method where the researcher watches and records participants behaviour without interfering in any way (from a distance).
• Content analysis 


  A research method which involves exploration of behaviour to see what categories, codes or themes emerge, and tallying each time material fits a theme. It converts qualitative data into quantitative data so that it can be more easily compared.
• Structured interviews 


  A research method that includes standardised questions, which are known as an interview schedule, and are usually asked face to face.
• Questionnaires 


  A research method that includes a list of written questions, which generate closed and / or open answers. These can be in person, online or through other methods (eg postal).
• Semi-structured interviews 


  A research method which involves asking participants questions, usually face to face. These can be in the form of an interview schedule, but could also include follow up questions to expand on answers of the questions asked.
• Correlational studies 


  A research method which involves comparing two continuous variables (co-variables) to see if there is an association / relationship between them.
• Case studies 


  A method which involves an in depth investigation of a phenomenon, which uses a descriptive analysis of a person, group or event. It is a holistic study through one or more methodologies that is usually longitudinal.
• Self reports 


  A method which involves a participant reporting on their own thoughts and feelings through methods such as interviews or questionnaires.
• Quantitative data


  A type of data that can be measured numerically by the psychologist, so that statistical analysis can be completed.
• Qualitative data


  A type of data that can be observed, but not measured numerically. It usually takes the form of words, thoughts and feelings, and is difficult to analyse.
• Primary sources 


  Information sources / data that is directly collected by the researcher first hand.
• Secondary sources 


  Information sources / data that have not been directly collected / created by the researcher.
• Cross sectional studies 


  A method which involves comparing one group of participants, representing a cross-section of society, against at the same point in time.
• Brain scans 


  A research method which involves taking images of the living brain to investigate brain function. Eg PET, fMRI, CAT scans.
• Longitudinal studies / research 


  A method which involves conducting research over a long period of time in order to observe long term effects of X on a specific behaviour. It may utilise a range of other methodologies such as case studies, interviews, etc.
• Lab 


  A location of research where scientific research and measurement can be taken using specialist / large equipment . Conditions and variables are controlled, and procedures are standardised.
• Online research


  A location of research where participants are accessed via the internet / social networks / mobile apps etc. Often involves questionnaires but can also be experimental, Correlational, etc.
• Target population


  The group of individuals that a researcher is interested in studying.
• Sampling frames 


  A group / population that is identified when it is unrealistic to study the whole target population.
• Random sampling 


  A sampling technique where participants are selected from the sampling frame, where everyone had an equal chance of being selected .
• Opportunity sampling 


  A sampling technique where participants are selected at the researchers convenience without knowing any details about the sample in advance.
• Systematic sampling 


  A sampling technique where every nth person on a list is selected by the researcher.
• Stratified sampling 


  A sampling technique where the target group is divided into subgroups, eg by sex, and then participants are selected randomly from each subgroup.
• Quota sampling 


  A sampling technique where the target population is divided into subgroups, eg by sex, and the participants are chosen from each subgroup at the convenience of the researcher.
• Self-selected sampling 


  A sampling technique where the participants volunteer for research.
• Snowball sampling 


  A sampling technique where participants are initially recruited by the psychologist and then those participants recruit further participants from people they know.