These questions are usually phrased: “Discuss [X's] theory of [Y]” or “Describe and Evaluate [X's] theory of [Y]” or “Critically consider the [X] explanation of [Y]”. Half of the marks are for AO1: the outline, and half of the marks are for AO2: the evaluation.
There are at least two ways you could approach the structure of a question like this
Describe the theory/explanation (AO1)
Although you are using many of the skills you developed during your AS Psychology course, the examiner now expects your responses to be more sophisticated. The mark schemes now demand that to obtain maximum marks for AO1 your descriptions must be substantial, accurate and well-detailed and the structure should be coherent with evidence of breadth and depth.
If you are well prepared for the examination, you will know what the main points of the theory are and will be ready to describe them clearly and in a logical sequence. Make sure you include all of the key points and explain them all in plenty of detail. Explain any terminology that you use (e.g., “The empathy- altruism hypothesis proposes that altruism is due to empathy; empathy is knowing what another person is feeling from their point of view, or mentally putting oneself in another person's shoes”). Explaining terminology shows the examiner that you understand the material.
The examiner will be looking for evidence of breadth and depth in your description. An essay with breadth gives coverage of most parts of a theory, while depth involves describing the theory in sufficient detail. The examiner is looking for a balance between breadth and depth, so you should try to give a reasonable amount of detail to each aspect of the theory. Avoid describing one aspect of the theory in great detail and missing other parts that are just as important. Also avoid just giving a basic overview of the theory and not including any detail. Be well prepared and aware of how much you can describe in the time available (about 15 minutes)
Back it up the theory with a study (AO2)
If you are evaluating an explanation or theory, the best arguments about how good it is come from studies: if a theory is supported by actual data that is a strong argument that it is a good theory. It makes sense to have the first study you mention to be one that supports the theory. Do not spend ages describing the minute details of the study when the question has asked you to evaluate a theory; instead, outline the findings and add commentary saying how the findings support or do not support the theory.
Criticise the study (Strengths and Weaknesses)
You have said that a study supports the theory, but no study is perfect. What is good about the study in terms of supporting the theory you are discussing. For example, is it high in ecological validity? If it is high in ecological validity it shows that the theory may be valid in real life situations (so tell the examiner!).
Next, what weakness(es) does the study have, that mean(s) that it may not support the theory after all? (if it was high in EV then extraneous variables were probably not well controlled – can you think of an extraneous variable that may have affected the results? Choose extraneous variables that are particularly relevant!)
Back up your criticism with a study that does not support the theory
Again, just outline the findings and add some commentary explaining why this study does not support the theory.
Strengths of this study
why is this study better than the previous one?
Weaknesses of this study…
Add more studies to support and refute the various aspects of the theory
Do not forget the commentary!
Contrast with another theory
A strong argument against a study is that another theory provides a better explanation for the research findings. A full explanation of how and why the other theory is better will obtain more marks.
Other possible strengths and weaknesses of a theory
Is the theory plausible? Does the theory seem to make sense with regard to our everyday experiences. To get marks for this you must say how it relates to everyday experience.
Gender bias – Has all the research been carried out on males? Are there assumptions that the theory makes that make it gender biased (e.g., Freud’s assumes that females are morally weaker than men; Kohlberg only used males in the research he used to develop his theory)
Culture bias – Does the theory only apply to western cultures? Make sure you explain why.
Is the theory unfalsifiable? Explain what this means.
Summarise and Conclude
If you have time, summarise the points you have made and make a general conclusion