Should You Guess on CEnT-S? Scoring Explained

The current CISIA scoring page gives +1 for a correct answer, 0 for a blank and −0.25 for a wrong answer. A penalty does not automatically mean that every guess is a bad choice. It means you need to consider your chance of being right and the time the decision takes.

The five-option assumption and its source

Article 1.2.1 of the CISIA CEnT regulation states that questions have five options with one correct answer. However, that PDF describes the 2025–26, five-section format. The current six-section structure page does not repeat the option count. We could not independently confirm the count for the newly added Reading section from those sources. The calculations below are therefore explicitly for five-option questions; check your current sitting instructions before applying them to a different format.

Show the working

Let p be your probability of choosing the correct answer. The expected raw-score change is:

E = p × 1 + (1 − p) × (−0.25) = 1.25p − 0.25.

That equals zero when p = 0.20. If you eliminate options correctly and then choose uniformly among the remaining options, p = 1 / n, where n is the number left.

These are averages over uncertain outcomes, not points you are guaranteed to receive. A single blind guess still scores either +1 or −0.25. If your elimination removes the correct answer, the favourable calculation no longer applies. Cross out an option because you can explain why it is wrong, not because it looks unfamiliar.

When should you skip in each section?

These are suggested decision rules, not CISIA instructions to leave questions unanswered. Move to another question within the section when the interface permits; finish your review before leaving that section.

At the end of a section, a fully blind five-option guess is neutral in expected raw points; leaving it blank avoids the risk of a loss. Reliable elimination makes a guess positive in expectation, if answering does not displace better opportunities. Your choice can also depend on whether you need to protect a score or accept more uncertainty.

Does normalisation change this logic?

No: CISIA's published normalisation adds a coefficient to raw performance. For a fixed coefficient, it adds the same amount whether you guess or leave a question blank, so it does not change the expected-value comparison above. It does not cancel the wrong-answer penalty or guarantee a particular university result.

For the university-specific interpretation, read What CEnT-S score do you need?. Practise decisions using the separate timers in our CEnT-S course, rather than treating the test as one transferable pool of time.