. . "Difficulty coefficient" can also be understood as "ease coefficient". If the test difficulty coefficient of a 10 score is 0.5, it can be understood that the average test score of this 10 score is 5. In the "reference sample questions", the difficulty coefficient of each sample question is published. The sample questions are the college entrance examination questions in the past few years, and the difficulty coefficient is the result measured after the Beijing college entrance examination, which is very accurate and highly reliable. Why should candidates study the difficulty coefficient of each test question? The "Examination Instructions" clearly stipulates: "The examination paper consists of easy questions, medium questions and difficult questions, with the medium questions as the main one, and the overall difficulty is appropriate." Generally speaking, the proportion of difficult questions in college entrance examination papers is 2:6:2 or 3:5:2. The previous "exam notes" have always been expressed in this way, but now they are expressed as "mainly medium-sized questions", but the data has not changed. Middle and low-grade questions account for 80%, and 750 points account for 600 points. So what are the middle and low-grade questions? Generally speaking, topics with a difficulty coefficient of 0.4-0.7 are medium, topics below 0.4 are difficult, and topics above 0.7 are easy.