Final answer:
The statement is true; a high correlation between a test question and the overall test score suggests that the question is a good measure of the test's intended ability or knowledge, thereby improving the test's validity.
Step-by-step explanation:
If the correlation between a test question and the overall test score is high relative to other items, then it is likely to be improving the test's validity. This statement is true. Higher correlation suggests that the test question is capable of predicting the overall performance of a student on the test. Test validity refers to how well a test measures what it is supposed to measure. If a question shows high correlation, it indicates that it is a good measure of the overall ability or knowledge that the test seeks to assess.
An example of this can be seen in standardized testing where certain questions might highly correlate with overall success in the subject being tested. This correlation provides a predictive value, making the test more accurate and helpful in determining a student's abilities. Typically, a correlation coefficient (often denoted as 'r') is used to measure the strength of the relationship between two variables. The closer the value of 'r' is to 1 or -1, the stronger the linear relationship between the two variables. Thus, if a test question highly correlates with the overall test score, generally denoted by a high 'r' value, it contributes positively to the validity of the test.