Chan created a composite measurement to determine how likely a child is to engage in delinquency from the age of 10 to 14. She tests the reliability for this instrument by performing a pilot study in which two groups each received five of the ten questions. She then compares the results, hoping they are similar. What method did Chan use?

Split-half Method.

Explanation:

Split half test is the method to assess the reliability of internal consistency.

Split-Half method is a reliability test in which to gain insight about a single knowledge, the test is divided into two parts. Then two groups of students or people are required to participate in the test at the same time. The scores of both the groups are assessed. A test that have high correlation suggests the reliability and will reveal how well or poorly the students will perform in the test.

In the given case, Chan has divided the test questions into five questions each for two groups, to check the reliability of instrument. The results of both the test are assessed with the hope that they have similar results. This is the method of testing reliability with the split-half method.

So, the correct answer is split-half method.