There are more self-assessment forms available than any student needs, and the usual failure is not having too few but using them badly, several early, taken quickly, reviewed lightly, and the most representative material spent before it could tell you anything.
The principle
A practice form is a measuring instrument, and its value depends on when you use it. Early on, you want a rough baseline and exposure to the format. Close to the exam, you want the most accurate estimate you can get.
That means sequencing matters: less representative material early, the most representative material saved for late.
Spending your best forms in the first two weeks is the most common way to arrive at the final fortnight with nothing left that would actually tell you where you stand.
A workable sequence
Early. A baseline. One assessment near the start of preparation, taken knowing it will be uncomfortable. Its purpose is to identify weak areas while there is still time to address them, not to predict anything.
Middle. One or two checkpoints. Spaced ten to fourteen days apart. These answer the only question that matters mid-preparation: is the trend moving? A flat trend here is a reason to change approach while changing it can still help.
Late. The most representative material you have. Close enough to the exam to be a genuine estimate, far enough out that a poor result still leaves room to act. Not the day before.
Prefer newer forms
Question style drifts. Newer forms generally reflect how the exam currently asks things, which matters both for the estimate and for the familiarity you are building.
Older forms remain useful for content exposure and early baselines, but weight recent material more heavily as you approach the date.
Free official questions
There is a publicly available set of practice questions released by the examination’s own publishers. It is widely regarded as the closest available approximation to real question style, and it is free.
Save it. It is most useful in the final couple of weeks, both as a check and as familiarisation with the exact phrasing conventions of the real thing. Using it in week one wastes the single most representative resource you have.
Do not take more than you can review
Every assessment costs the sitting plus a review of comparable length. If you are taking them faster than you can review them, you have converted a diagnostic tool into an anxiety schedule.
Three to five, properly reviewed, is a better plan than eight skimmed. The review is where the information transfers; the score is just the receipt.
Reading the numbers honestly
Any single result is an estimate with real error bars. Conditions vary, sleep, time of day, which form you happened to sit, and a five-point movement between two assessments is well inside noise.
What carries information is the direction across three or more, and whether the areas you have been working on are the areas that have improved.
That is easier when your question bank reports the same breakdown. QBankly groups performance by system and discipline, so an assessment result can be read against what you have actually been practising. Everything else is a number to be noted and not dwelt on.
Reviewing a form properly
The review is where the value is, and self-assessment forms make it harder than a question bank does because you often cannot see full explanations for every item.
Work with what you have. For each question you got wrong or were unsure of, write down what you think the reasoning should have been, then go and confirm it in your own resources. That is slower than reading a supplied explanation, and it is a better learning event, because you had to reconstruct the reasoning yourself.
Group your errors afterwards. If four of them are in one system, that is a signal. If they are scattered across systems but share a shape, all management questions, all involving interpretation of a common investigation. That is a more useful signal still, and it is the one a per-system breakdown will not show you.
Conditions matter more than the form
Two results are only comparable if you sat them comparably. Same time of day, same single sitting, similar sleep.
Students routinely take one form fresh on a Saturday morning and the next in two halves after a working day, then read the difference as progress or decline. It is neither.
Record the conditions. When a result surprises you, check them before you conclude anything about your knowledge.
Frequently asked questions
Should I use older forms at all?
They are fine early, when you mainly want a rough baseline and exposure to the format. Their style drifts from the current exam, so they are a poorer guide close to the date.
What if I run out of forms?
That usually means you were taking them too frequently. Assessments are for calibration; the actual improvement comes from question practice and review between them.