psych key science skills

controlled experiment

a type of investigation in which the causal relationship between two variables is tested in a controlled environment; more specifically, the effect of the independent variable on the dependent variable is tested while aiming to control all other variables

independent variable (IV)

the variable for which quantities are manipulated by the researcher and is the variable that is assumed to have a direct effect on the dependent variable

dependent variable (DV)

the variable the researcher measures in an experiment for changes it may experience due to the effect of the independent variable.

controlled variables

variables other than the IV that a researcher holds constant (controls) in an investigation, to ensure that changes in the DV are solely due to changes in the IV

case study

an in-depth investigation of an individual, group, or particular phenomenon (activity, behaviour, event, or problem) that contains a real or hypothetical situation and includes the complexities that would be encountered in the real world

correlational study

a type of non-experimental study in which researchers observe and measure the relationship between two or more variables without any active control or manipulation of them

classification

the arrangement of phenomena, objects, or events into manageable sets

fieldwork

any research involving observation and interaction with people and environments in realworld settings, conducted beyond the laboratory

population

 the group of people who are the focus of the research and from which the sample is drawn

sample

a subset of the research population who participate in a study

convenience sampling

any sampling technique that involves selecting readily available members of the population, rather than using a random or systematic approach

random sampling

any sampling technique that uses a procedure to ensure every member of the population has the same chance of being selected

stratified sampling

any sampling technique that involves selecting people from the population in a way that ensures that its strata (subgroups) are proportionally represented in the sample

extraneous variable

any variable that is not the independent variable but may cause an unwanted effect on the dependent variable

confounding variable

a variable that has directly and systematically affected the dependent variable, apart from the independent variable

participant related variables

characteristics of a study’s participants that may affect the results

order effects

the tendency for the order in which participants complete experimental conditions to have an effect on their behaviour

placebo effect

 when participants respond to an inactive substance or treatment as a result of their expectations or beliefs

experimenter effect

when the expectations of the researcher affect the results of an experiment

situational variables

any environmental factor that may affect the dependent variable

non standardised instructions and procedures

when directions and procedures differ across participants or experimental conditions

demand characteristics

cues in an experiment that may signal to a participant the intention of the study and influence their behaviour

counterbalancing

a method to reduce order effects that involves ordering experimental conditions in a certain way

single-blind procedure

a procedure in which participants are unaware of the experimental group or condition they have been allocated to

double-blind procedure

a procedure in which both participants and the experimenter do not know which conditions or groups participants are allocated to