- Sign in to Ans.
- Click Courses in the menu on the left.
- Select the assignment and click Analytics in the menu on the left.
- Click Exercise analysis. The Exercise analysis page is shown and a couple of insights are given:
There are five values that are calculated for each question, which give information about the question. These values are all calculated for multiple choice questions. The p-, Rit- and Rir-values are also calculated for open questions.
- p: Rate of difficulty. The p-value is the percentage of students that correctly answered the question. The higher the p-value, the easier the question is.
p = [number of students that answered this question correctly] / [total number of students]
- p': Rate of difficulty corrected for the guess correction. The p'-value is the percentage of students that know the question. This value is minimal 0,25 and maximal 0,9. If the p'-value equals 0,5 it can be said that a maximum discrimination between good and weak students is found.
p' = p - [ (1-p) / (number of options for this multiple choice question - 1) ]
- Rit: Relation of the question to all questions in the test. The higher the Rit-value, the better the question fits the test. A value higher than 0,40 is very good, a value between 0,30-0,39 is good, but can be better, a value between 0,20-0,29 is a doubt and a value lower than 0,19 indicates that the question is bad. The equation is given below
- Yg = average total score of students that got this question correct
- Yf = average total score of students that got this question incorrect
- Sy = standard deviation of the total score
- Sy = standard deviation
- p = p - number of points for the question
- q = (1-p)
- Rir: Relation of the question to all other questions (so all questions except this one). This value measures the same as the Rit-value, but the Rir-value is more exact, while it is not compared to itself. A value higher than 0,40 is very good, a value between 0,30-0,39 is good, but can be better, a value between 0,20-0,29 is a doubt and a value lower than 0,19 indicates that the question is bad. The equation is given below.
- Rk: Corrected guess effect. The normal guess effect of for example 25% for a 4-choice question with one correct answer is corrected for the amount the other alternatives are chosen. This way the corrected guess effect can be higher than the normal gambling chance.
For every question, based on the p-, p'-, Rit-, Rir- and Rk-values, a conclusion is made. This conclusion can be:
- Good question: All values are good.
- Easy question: The p- and p'-values are probably too high.
- Difficult question: The p- and p'-values are probably too low.
- Needs attention: The Rit- and/or Rir-values can be off. Look at which number is divergent.
A line is placed under a value if the value is divergent.
For each question, a drop-down menu is shown underneath the values that give insight into the questions. In the menu, four options are shown:
- Contributing: This is the standard option, the question contributes to the grades of the students.
- Bonus: The question will not be taken into account in the maximum score that can be gained, but it can be a bonus for the students who got it correct.
- Full points: Every student will get the full (maximum amount of) points for this question.
- Disabled: The question and the points of the question will be taken out of the exam and will not be taken into account for the grading.