An experimental procedure in which neither the researcher doing the study nor the participants know the specific type of treatment each participant receives until after the experiment is over; a double-blind procedure is used to guard against both experimenter bias and placebo effects.

• Single blind control

• Researcher objectivity

• Researcher bias

• Double blind control

a scientific prediction stating that an effect will occur and whether that effect will specifically increase or specifically decrease, depending on changes to the independent variable.

• null hypothesis

• experimental hypothesis

• one tailed hypothesis

• two tailed hypothesis

The dependent variable is measured before the independent variable has been manipulated and then again after it has been manipulated.

• pre-test post-test design

• correlation

• manipulation

• trial

The degree to which a study consistently measures a variable. For example, if a researcher develops a new questionnaire to evaluate respondents’ levels of aggression, the construct validity of the instrument would be the extent to which it actually assesses aggression as opposed to assertiveness, social dominance, or irritability. 

• bidirectional ambiguity

• construct validity

• internal validity

• external validity

When researchers reflect on how their own biases may have affected their research process and the findings of their research

• biases

• reflection

• personal reflexivity

• review

When a researcher reflects on their choice of method or materials may have influenced the findings of the study - for example, how did using a participant observation affect the potential behaviour of the people being studied?

• Epistemological reflexivity

• Method triangulation

• reflexivity

• method review

the degree of agreement among researchers recording behaviour during an observation.

• inter-rater reliability

• researcher triangualtion

• collaboration

• consensus

The level of responding before any treatment is introduced and therefore acts as a control condition. For example, measuring normal brain activity before being asked to recall a stressful event.

• Baseline

• Borderline

• Starting point

• Measurement point

A condition that does not receive the treatment or intervention that the other conditions do. It is used to see what would happen if the independent variable were not manipulated.

• third condition

• control condition

• baseline group

• non experimental group

The probability that, if the null hypothesis were true, the result found in the sample would occur.

• probability

• p value

• value point

• prevalence