How to Write A-Level Psychology Essays: Where Evaluation Comes from in Cambridge 9990 and How Description and Evaluation Are Graded in Paper 3

For A-Level Psychology essay questions, the challenge lies not in "memorizing studies," but in evaluation: even when students have memorized the aims, procedures, and findings of a study, some only score marks for description, while others score highly in the evaluation section. The difference is whether they have a systematic evaluation toolkit. Based on the Cambridge International 9990 Psychology syllabus, this article clarifies where the essay questions are, how they are graded, and from which angles to write the evaluation. Note: We could not find a course page for IAL Psychology on the Pearson website, so this article only covers Cambridge 9990. For the overall structure and the 12 core studies, see How A-Level Psychology is Assessed.

1. Where Are the Essay Questions?

The topics for the structured essays in Paper 3 will be different from the topics tested in the short-answer questions for the same topic; the topics tested in Paper 3 are also different from those in Paper 4. This structure remains the same across the 2024–2026, 2027, and 2028–2030 versions of the syllabus.

2. How Does the Syllabus Define "Analysis and Evaluation"?

Cambridge 9990 has three assessment objectives: AO1 Knowledge and Understanding, AO2 Application, and AO3 Analysis and Evaluation. The official definition of AO3 is to analyze and evaluate psychological concepts, theories, studies, evidence, and methods from the perspective of issues and debates, including:

• Identifying biases in psychological data and studies;
• Explaining the strengths and limitations of concepts, theories, studies, and methods;
• Using a range of evidence to illustrate the complexity of psychological issues and debates;
• Drawing conclusions about arguments based on a reasoned consideration of available evidence.

Across the papers, AO3 accounts for 48% in Paper 3, the highest of all papers; it accounts for 30% in Paper 1. This means that nearly half of the marks in the A Level Paper 3 are for evaluation.

3. Understand the Command Words First

Among the command words listed in the syllabus, the most critical ones for essay questions are:

• Describe: State key points, giving features and main characteristics. Part (a) of Paper 3 is a description question; no evaluation is required, and writing evaluation will not score marks for this part;
• Evaluate: Judge the quality, importance, extent, or value of something. Part (b) of Paper 3 is an evaluation question;
• Compare: Identify or comment on similarities and/or differences. Section B of Paper 1 may require comparing studies;
• Explain, Analyse, Suggest: These mean giving reasons or relationships with evidence, examining parts and their relationships in detail, and making suggestions in situations with multiple plausible answers, respectively.

A common mistake is writing a lot of evaluation in part (a) and then just repeating the study in part (b). Part (a) is for description only, and part (b) is for evaluation only; the division of labor between the two parts must be clear.

4. Where Does Evaluation Come From: Two Official Toolkits

Toolkit 1: Evaluation Concepts for Research Methods

The research methods section of the syllabus requires evaluating studies from these angles:

• Validity: Including ecological validity; evaluated in terms of subjectivity/objectivity, demand characteristics, and generalizability;
• Reliability: Inter-rater and inter-observer reliability, test-retest reliability; replicability;
• Ethics: Evaluating studies against ethical guidelines (for both human participants and animal research);
• Sampling: Evaluating different sampling methods, including whether conclusions can be generalized;
• As well as the strengths and limitations of the research methods themselves, such as experiments, self-reports, case studies, observations, correlational studies, and longitudinal studies.

Toolkit 2: Issues and Debates

The syllabus specifies the issues and debates to be integrated:

A highly practical feature: After each sub-topic in every A Level topic, the syllabus lists the "most relevant issues, debates, and research methods." For example, in the sub-topic on using virtual reality to study persecutory delusions in clinical psychology (the key study is Freeman et al., 2003), the syllabus lists: individual and situational explanations, using children in research, idiographic versus nomothetic approaches, case studies, and generalizing research findings. This list serves as the evaluation outline for the topic, and you must use it during revision.

5. How to Write Part (b) of Paper 3

The following framework is based on practical experience:

1. Select three to four evaluation points: Choose from the list provided in the syllabus for the topic. Ideally, include both research method angles (validity, reliability, sampling, ethics) and issues and debates angles (e.g., nature vs. nurture, reductionism vs. holism);
2. Develop each evaluation point fully:
   • Identify: State whether it is a strength or limitation in a specific area;
   • Provide evidence: Use specific details from the study or theory to illustrate, such as who the sample was, where it was conducted, and how it was measured;
   • Explain the impact: Discuss what this means for the credibility or generalizability of the conclusions;
3. Include both strengths and limitations, and compare them: For example, "laboratory control increases reliability but decreases ecological validity." Linking the two demonstrates "complexity" better than just listing them separately;
4. Cite other evidence: The definition of AO3 includes "using a range of evidence," so you can use another study to support or refute the point;
5. Conclude at the end: Overall, how strong is the evidence for this study or theory, and to what extent can it explain the phenomenon? This corresponds to AO3 "drawing conclusions about arguments."

Evaluation must be specific. A generic statement like "the sample is too small" or "it lacks ecological validity" could apply to almost any study and is unconvincing. Instead, write: because the sample consists only of a specific group, the results must be generalized to another group with caution, because...

6. Section B of Paper 1

Section B of Paper 1 focuses on the 12 core studies, requiring you to evaluate and potentially compare them. When preparing (based on practical experience):

• For each core study, organize the information according to the syllabus dimensions: psychological theme, background, aims, procedure (method, sample, design, controls, variables), ethics, findings, conclusions, and the strengths and limitations of each stage of the research;
• Then, link each study to the five AS issues and debates;
• Practice "comparing": write about the similarities and differences of two studies side-by-side using the same dimensions (method, sample, ethics, validity), rather than just writing a separate paragraph for each.

7. How to Allocate Your Time

Here is a practical recommendation: both papers are 90 minutes long and worth 60 marks, which is about 1.5 minutes per mark. Each topic in Paper 3 is worth 30 marks and should take about 45 minutes; of this, the 16-mark structured essay should take about 24 minutes, with 8–9 minutes for part (a) and around 15 minutes for part (b). Do not write too much in part (a); save your time for the higher-marked evaluation.

8. Common Reasons for Losing Marks

Here is a practical summary:

• Failing to separate description and evaluation: Writing evaluation in part (a) and just repeating the study in part (b);
• Using evaluation labels only: Just writing "lacks ecological validity" without explaining why or what the impact is;
• Only writing limitations: Evaluation is about judging value, so both strengths and limitations must be included;
• Not integrating issues and debates: The definition of AO3 explicitly requires evaluation from the perspective of issues and debates;
• No conclusion: Stopping after listing a series of strengths and limitations;
• Inaccurate terminology: Confusing validity and reliability, or describing demand characteristics as "participants lying."

9. How to Practice

1. Use the syllabus as an evaluation outline: Copy down the "relevant issues, debates, and methods" listed after each sub-topic, and write one or two specific evaluation points for each;
2. Get the mark schemes: Mark schemes for past papers are usually obtained through your school; ask your teacher for them and use them for self-assessment after completing your practice;
3. Practice writing (a) and (b) separately: Set a time limit of 8 minutes for description and 15 minutes for evaluation;
4. Build your terminology: Terms such as ecological validity, demand characteristics, generalisability, inter-rater reliability, reductionism, determinism, idiographic, and nomothetic—ensure you can spell, explain, and apply them correctly.

Final Thoughts

Scoring high on A-Level Psychology essay questions comes from using a systematic evaluation toolkit: research method angles (validity, reliability, ethics, sampling) combined with issues and debates angles. Every evaluation point must be supported with evidence, its impact explained, and a conclusion drawn. The syllabus has already listed the relevant issues and debates for each topic, which serves as the best revision outline. If you need marking and tutoring for your A-Level Psychology essays, feel free to chat with our teachers.

Verification note: This article was verified in September 2026: The duration, marks, and essay section settings for Paper 1 and Paper 3, the 6 marks for description and 10 marks for evaluation in the Paper 3 structured essay, the definitions of the three assessment objectives and their weightings across papers, the meanings of command words, the issues and debates for AS and A Level, the evaluation requirements for validity, reliability, ethics, and sampling in research methods, and the relevant issues and debates listed after each sub-topic (including the example of the virtual reality study in clinical psychology) are all from the Cambridge International Psychology 9990 syllabus for 2027; the structure of Paper 3 is the same in the 2024–2026 and 2028–2030 syllabuses, sourced from the respective versions. The IAL Psychology page on the Pearson website displayed "Page not found" at the time of our verification (see article 172 on this site). The writing framework, time allocation, common reasons for losing marks, and practice methods are our practical recommendations.

References:

• Cambridge International: AS & A Level Psychology (9990)