When evaluating the reliability of retest, the time interval between two tests is very important, and the appropriate interval is ().

The time interval between two tests is very important when evaluating the degree of re-examination. If the time interval is too short, candidates can remember the last answer, which will have a strong memory effect and practice effect; If the time interval is too long, there will be many other factors affecting the subjects' answers. Therefore, the longer the time interval, the lower the correlation coefficient between the two tests. According to general experience, the interval of half a month to half a year may be more appropriate.