AICE Psychology Paper 2: Comprehensive Review

Sampling Methods

Different techniques used to select individuals from a population for a study.

Simple Random Sampling

Every individual has an equal chance of selection.

Stratified Sampling

The population is divided into strata, and random samples are taken from each stratum.

Cluster Sampling

The population is divided into clusters, some clusters are randomly selected and all individuals within chosen clusters are sampled.

Systematic Sampling

Every nth individual is selected from a list of the population.

Convenience Sampling

Samples taken from a group that is easy to access, which can introduce bias.

Voluntary Response Sampling

Individuals choose to participate, often leading to biased results due to strong opinions.

Experimental Design Principles

Key principles ensuring reliability and validity of experimental research.

Control

Keeping other variables constant to isolate the effect of the treatment.

Randomization

Randomly assigning subjects to treatment groups to reduce bias.

Replication

Repeating the experiment on many subjects to ensure reliability.

Blocking

Grouping subjects with similar characteristics and randomly assigning treatments within these blocks.

Observational Study

Observes individuals without manipulating variables; cannot establish causation.

Experiment

Applies treatments to subjects and observes effects; can establish causation.

Subjects/Experimental Units

Individuals participating in the study.

Factors

Explanatory variables manipulated in the experiment.

Levels

Different values of the factors.

Treatments

Combinations of factor levels applied to subjects.

Placebo

An inactive treatment used to control for psychological effects.

Blinding

Keeping subjects or experimenters unaware of treatment assignments to prevent bias.

Double-Blind

Both subjects and experimenters are unaware of treatment assignments.

Internal Validity

The extent to which the experiment measures what it intends to, without confounding variables.

External Validity

The extent to which results can be generalized to other settings or populations.

Reliability

The consistency of a measure; a reliable study yields similar results under consistent conditions.

Ecological Validity

The extent to which findings can be generalized to real-life settings.

Mundane Realism

How closely the experimental tasks mirror real-world activities.

Quantitative Data

Numerical data that can be measured and analyzed statistically.

Qualitative Data

Descriptive data that provides insights into participants' thoughts and behaviors.

Measures of Central Tendency

Mean, median, and mode used to summarize data.

Measures of Dispersion

Range and standard deviation indicate data variability.

Directional (One-Tailed) Hypothesis

Predicts the direction of the expected effect.

Non-Directional (Two-Tailed) Hypothesis

Predicts an effect without specifying the direction.

Null Hypothesis

States there is no effect or difference; used as a baseline for statistical testing.