1. Using the person by item sheet, calculate the following:

a) The reliability of a test twice as long (assume you add similar items).

b) The reliability of a test with only 5 items (again, assume you add similar items).

2. Explain the results from item one above.

3. Compute the reliability of a score made from the difference between the scores from the first 5 items and the scores from the second five items. This can be done two different ways, see page 149.

4. Explain the results from item 3 above.

5. Estimate the true scores of the 8 people for the entire test.

6. What do the scores mean in item 5 above?

7. Assume you want to insure that the information you report for person 3 about his/her ability level would be 95% accurate. What number(s) would you report?