How to Study Lifespan and Behavioral Changes of Individuals

Life Span and Developmental Psychology

Scientists use three main research designs to study human lifespan development; longitudinal, cross sectional and sequential designs. The longitudinal design involves the study of selected participants repeatedly over a given span of time. This can be over a short time ranging from a few months to a few years, or can be over a long period of time spanning to a decade or more. The advantage that the researchers have in using this approach is that they are able to observe common patterns among the participants as well as differing trends among them in the early as well as late events in their lives. On the other hand, the weaknesses that it has are that there is possibility of distortion of the age related changes occasioned by participants dropping out, the cohort effects and practice effects in the process of the research.

Cross-sectional design is when the researcher engages in studying different groups of participants who are of different ages at the same given point in time. Since the study is done once at the chosen time, it is not affected by the participant dropouts and also not subject to the practice effect. The challenge with this approach however is one cannot study the individual participant's developmental trends and t he age differences may not come out clearly as the cohort effects may distort it.

The other design is the sequential design where the researcher chooses either the cross-sectional design or the longitudinal approach and conducts several and similar studies often referred top as sequences at varying times. The advantage of this approach is that it allows for the longitudinal and cross-sectional comparisons as well as gives the researcher that easy time in identifying and eliminating the cohort effects. The challenges that may be experienced may be similar to those in the longitudinal and cross sectional above, though this approach will help identify these challenges.

Methods of human behavior observation and reporting