Some Methodology and Strategy Problems in Longitudinal Research

Abstract

Most researchers can understand that longitudinal research involves many problems that do not arise in traditional cross-sectional research, be it laboratory experiments or field studies. However, the full implications of planning, performing, and reporting a longitudinal project cannot be foreseen by theoretical analyses alone. They must be learned through experience. The consequences of bad planning can be serious in crosssectional studies, but in longitudinal research they can be disastrous. The need for foreseeing problems and handling them effectively is therefore much greater in longitudinal research. In this chapter a few problems met in longitudinal research, especially in large-scale studies of groups representative for ages, will be described and discussed against the background of experiences gained in a longitudinal project at the Department of Psychology, University of Stockholm.