Areading service for the visually impaired requires each reader applicant to prepare and submit a one-hour interview tape of material chosen by the service to determine whether the reader has pleasing vocal characteristics and is accent free so that it is not necessary to use the same reader every time. the reading service is trying to limit problems associated with the service characteristic of:

Heterogeneity

Explanation:

Heterogeneity means diversity. The prefix "Hetero" means "other" or "different". Thus an heterogeneous group is a group that is composed by dissimilar parts and where each part is different from the other.

In this example, the reading service asks each applicant to submit a one-hour interview tape to determine the reader vocal characteristics and see if they are accent-free so they can use the same reader for their purposes and not be changing readers because of particular characteristics such as accents.

Thus the reading service is trying to limit problems associated with the characteristics of heterogeneity which would imply to have dissimilar readers where all of them are really different from each other.  

answer; validity;