Psychology
Introducing key terms -
Deciding on a research question

Aim of the 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 affect the DV in one specific direction/outcome e.g. alcohol slows reaction time.

Non-Directional Hypothesis — A hypothesis that suggests there will be a difference/relationship between variables, the IV will affect the DV, but does not state a specific direction/outcome for results e.g. alcohol affects reaction time.

Null Hypothesis — A hypothesis that suggests there will be no difference/relationship between variables, any that does occur does so by chance e.g. alcohol will have no effect on reaction time.

Independent Variables (IV) — The variable the psychologist manipulates and controls to see how it affects behaviour.

Dependent Variables (DV) — The variable which is measured (usually the participants’ behaviour) by the psychologist.

Co-variables — Co-variables indicate two 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 measured or manipulated by the researcher, that affect SOME participants’ behaviours but not others, having negative consequences for validity.

Extraneous Variables — Variables in a study that are not being measured or manipulated by the researcher but affect the results (DV) of ALL participants’ behaviour equally.