Cesuur – a matter of passing or failing an examination

If you answer 55% of the questions in an exam correctly, do you automatically pass? No... whether or not you pass a test depends on the pass mark that applies to that test. The pass mark is the boundary between a pass and a fail. But how is the pass mark determined and which (test) aspects influence that pass mark?   

How do you determine the caesura?

We distinguish four pillars for determining the cut-off point:

  1. Test with closed questions;
  2. Level of difficulty of the questions in the test;
  3. Weight of the key;
  4. Expected success rate.

In doing so, we assume an absolute break.

Absolute caesura versus relative caesura

The absolute cut-off point is a predetermined cut-off point. This cut-off point is fixed, regardless of the scores of the group of students. The cut-off point determined retrospectively is the relative cut-off point. The relative cut-off point takes into account the scores of the group. The absolute cut-off point is used most often. The relative cut-off point is useful when you do not know how a test will ‘perform’, for example in the case of a new course or test format.

 1. Test with closed questions

In the event of a closed-ended test There is always a chance that a student will answer the question correctly, even if they do not actually know the answer. We call this the guessing chance. The size of this guessing chance depends on the number of answer options. Suppose a test has a total of 60 questions, each worth 1 point and with 4 answer options. The guessing chance is then 25% (1 in 4). This means that a student can already score 15 points (¼ of 60) by guessing.

When determining the cut-off mark, you usually take into account the probability of guessing correctly. In practice, this means that the cut-off mark is higher because the probability of guessing correctly is factored in. In this case, you calculate the cut-off mark as follows.

Example
  • Chance of advice = 25% = 15 points
  • Total number of points – number of points to be earned by guessing: 60-15 = 45 points
  • Cutoff for this (smaller) number of points: 55% of 45 = 24.75
  • Cutoff: estimated points 15 + 24.75 = 39.75
  • 39.75 is 66.25% of 60 points.
  • Instead of 55%, the breakpoint is at 66.25%.

2. Level of difficulty of the questions in the test

You can determine the caesura in a number of ways, while taking into account the difficulty level of the questions. A method that is often used is the Angoff method. In this method, various experts review all questions in terms of difficulty. They assess what percentage of candidates who are just strong enough to pass would have answered the question correctly. The percentages of the various experts are then added up and the average forms the cut-off point.

Example

A group of five teachers will take the next steps.

  1. Consider a hypothetical group of students who have just mastered the material sufficiently.
  2. For each of the following questions, answer what percentage of these students will answer the question correctly.
  3. Omit the highest and lowest percentages for each question. Take the average of the remaining percentages.

Average percentages (extremes excluded):

  • Question 1: 50%
  • Question 2: 40%
  • Question 3: 80%
  • Question 4: 70%
  • Question ..

Added up and averaged: 60% cut-off point

3. Weight of the key

If a test is important for the practice of the profession and/or concerns a final examination, then you apply a high pass mark. This also applies if there is a high risk of damage in the work. For example, the pass mark for a medical examination is likely to be higher than for many other examinations.

The opposite is also true, of course. When a (formative) digital test If the intention is to measure progress that does not count towards the final result, you can lower the cut-off point.

4. Expected success rate

You can also adjust the pass mark based on an expected pass rate. For example, if you expect a test to be very easy for the target group because all candidates are highly educated and the test only contains simple comprehension questions. In that case, the expected pass rate is very high and you can choose to raise the pass mark. If you expect the opposite, that the test will be very difficult for most people, you can lower the pass mark.

Conclusion

Think carefully when determining a pass mark. A fixed ‘percentage of questions answered correctly’ or ‘number of points achieved’ is not always a good indicator. There are various factors that determine whether the pass mark is set higher or lower. Consult with colleagues and record the decisions made.