The purpose of a(n) __________ is to review research studies and help researchers consider the areas of potential harm in their proposed studies

For security and confidentiality reasons, once the results of a study are reported in a journal or at a conference the data should be destroyed

Indicate whether this statement is true or false.

Hart and Risley (1999) found differences in children's vocabulary at 30 months old. To what did they attribute these differences?

a. the average number of minutes of television children watch per day b. the average number of words spoken to children per minute c. the average number of books read to children each night d. the nutritional deficiencies of the children