实验动物随机分组 z-bo 2020-10-13 565

　　In animal experiments, it is often necessary to divide the selected experimental animals into several groups according to the research needs. In order to avoid the influence of human factors, the random number table is often used for random grouping.

　　1. The experimental unit was randomly divided into two groups, with 14 mice, and the random number table was used to divide them into two groups. First, the mice are numbered 1, 2, 3...14 in sequence, and then transcribe 14 numbers from a certain line of the random number table. The arrangement is as follows:

　　Animal Number: 1 2 3 4 5 6 7 8 9 10 11 12 13 14

　　Random number: 1 6 22 77 94 39 40 64 43 54 82 17 37 93 23

　　Group: B B A B A A B A B B A A A A

　　Now let the singular number represent group A and the even number represent group B. As a result, there are 8 animals included in group A. There are 6 animals included in group B. If the two groups are equal, one must be reduced from group A to group B. Which mouse should be included in group B, the random number table can still be used. After the 14 numbers in the above copy, a number is copied as 78. This number is divided by 8. Because there are 8 mice in group A, it is divided by 8 and the remainder is 6. So the 6th A (namely the mouse written as No. 12) was assigned to group B. After this adjustment, the distribution of the two groups of mice is as follows:

　　Group A: 3 5 6 8 11 13 14

　　Group B: 1 2 4 12 7 9 10

　　2. Divide the experimental unit into three groups at random, with 15 animals, and randomly divide them into groups A, B, and C. After numbering the animals, copy 15 numbers from the random number table according to the above method, and all numbers are 3 Divide, and use the remainder 1, 2, and 3 to represent A, B, and C. The result is classified into 6 animals in group A, 4 animals in group B, and 5 animals in group C, namely:

　　Animal Number: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

　　Random teaching items: 18 62 40 19 12 40 83 95 34 19 44 91 69 03 30

　　Group: C B A A C A B B A A B A C C C

　　To make the number of animals in the three groups equal, one of the six animals originally returned to group A must be assigned to group B. You can continue to copy a number from the random number table according to the diagonal line, get 60, divide it by 6, and divide it up (equivalent to the remainder of 6), and you can change the sixth animal A (namely No. 12) to group B. The animal numbers of each group after adjustment are as follows:

　　Group A: 3 4 6 9 10

　　Group B: 2 7 8 11 12

　　Group C: 1 5 13 14 15