Assessment objectives Key Terms

Double‑blind

A design where both participants and researchers are unaware of group assignments.

Random assignment

The random allocation of participants to experimental conditions to balance individual differences.

Randomisation

The random assignment of participants to experimental conditions to balance confounding variables across groups.

Double‑blind

A design where neither participants nor experimenters know which condition participants receive, reducing expectancy effects.

Randomised Controlled Trial

An experimental design in which participants are randomly allocated to conditions, allowing causal inferences by controlling for confounding variables.

Within‑Subject Design

A design where the same participants experience all experimental conditions, thereby controlling for individual differences.

Qualitative data

Non‑numeric information such as interview transcripts, field notes or photographs that provide depth and context to human behaviour.

Content analysis

A systematic coding and categorising technique used to analyse textual, visual or audio data for the presence of specific words, themes or concepts.

Central Tendency

Statistical measures (mean, median, mode) that describe the central point of a data distribution.

Standard Error

An estimate of the variability of a sample statistic (e.g., mean) across repeated samples from the same population.

Placebo Effect

A beneficial change in a participant’s condition that occurs after receiving an inert treatment, driven by the participant’s expectations.

Internal Validity

The degree to which a study accurately establishes a causal relationship between variables, free from confounding factors.

Effect size

A statistic that quantifies the strength of a relationship or the magnitude of a difference, such as Cohen’s d or Pearson’s r.

Random assignment

The process of allocating participants to experimental conditions purely by chance, ensuring comparable groups.

Internal validity

The degree to which a study accurately establishes a causal relationship between variables, free from confounding influences.

Counterbalancing

A methodological strategy that systematically varies the order of experimental conditions across participants to control for order effects.