Response stability in social research: lessons from a longitudinal study of the family-building process

"Responses to questions, phrased to elicit identical answers from the same individuals over time, are compared. The questions were used in a South African longitudinal study on the family-building process. Although consistency for certain questions was high, consistency was particularly low for questions on family-planning methods used and desired number of children at the time of marriage.... The need to evaluate the quality of data obtained in survey research, especially where heavy reliance is placed on memory recall, is stressed." (summary in AFR)