Calculation of difficulty:

(1) difficulty refers to the proportion or percentage of correct answers. This statistic is called the difficulty or difficulty of the test questions. The difficulty is generally represented by the letter P. The greater the P, the simpler the test questions, and the smaller the P, the more difficult the test questions.

The test questions should be graded, so the difficulty of each test question should be different, which should be specially considered when doing the test questions.

(2) Calculation formula:

P= average score/perfect score.

For example, the average score of the first question is 8.5, and the full score of this question is 10, so the difficulty of the first question is P=8.5÷ 10=0.85.

Example: 1 has a perfect score of 4, and 20 of the 50 students in the class got it right, so the difficulty of 1 is.

P= proportion or percentage of correct answers =20÷50=0.4 or average score =4×20÷50= 1.6.

P= average score/full score = 1.6/4 = 0.4.