Psychology · IA Experimental study
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Write a top-mark Psychology experimental study.

A step-by-step writing frame for the IB Psychology Internal Assessment. Partially replicate a simple, ethical published study, operationalise your IV and DV, write research and null hypotheses, run the right inferential statistical test, and evaluate your design — with the four assessment criteria built in.

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📄 Official IB subject brief (ibo.org ↗) — your teacher or IB coordinator can share the full subject guide.

How it's marked. Across four criteria: A Introduction /6, B Exploration /4, C Analysis /6 and D Evaluation /6 = /22, in a report of about 1,800–2,200 words reporting a simple experiment.
The rules that define a strong study: Replicate a simple ethical study, operationalise your IV and DV, run the right statistical test, and evaluate the design against the original study with realistic improvements.
Untitled study 0 words

IB Psychology IA help, examiner-written

The IB Psychology Internal Assessment is a report on a simple experiment that you design and run as a partial replication of a published study, written up in about 2,200 words. This examiner-written writing frame walks you through the method step by step — choose a simple, ethical, replicable study and state its aim and theory, operationalise one independent variable (IV) and one dependent variable (DV), write a research hypothesis and a null hypothesis, justify your experimental design with proper sampling and controls, run the experiment ethically, then report your results and evaluate your design. Each step is paired with the assessment criteria, worked good-and-bad examples and the traps that cost marks, and your report exports to DOCX or PDF. It is free to start: the planning sections are free, and the later sections are a one-time unlock per tool. Sign in to save your work and sync it across devices.

Replication, the IV and DV, and hypotheses

A strong IA begins with the right study: a simple, ethical, well-known experimental effect — such as levels of processing, the Stroop effect or anchoring — that you can reproduce safely in a classroom. You operationalise the independent variable as the exact conditions you manipulate and the dependent variable as the exact number you measure, then state a research hypothesis (directional where the theory predicts a direction) and a null hypothesis. Keeping these operational definitions consistent across the Introduction, Exploration and Analysis is what holds the whole report together.

Descriptive and inferential statistics

The Analysis criterion rewards appropriate descriptive statistics — a measure of central tendency and of dispersion, with a clear graph — followed by an appropriate inferential statistical test that is justified, applied correctly and interpreted against the null hypothesis. The design and the level of your data decide the test: an independent-measures design with interval data points to an independent-samples t-test, while ordinal data or a failed assumption points to a non-parametric alternative such as Mann–Whitney U. You report the test statistic, the p-value and the decision on the null in full.

Evaluating your design · examiner-written

The Evaluation criterion decides the top band: discuss your findings in relation to the original study and theory, then evaluate the strengths and limitations specific to your own design — not generic textbook limitations — and offer realistic modifications that would genuinely improve validity. The study must stay strictly ethical throughout: informed consent, the right to withdraw, no stress and no meaningful deception. It is free to start: the planning sections are free, and the later sections are a one-time unlock per tool. Sign in to save your work and sync it across devices.