Multiple cohort study

Astudy in which more than one group, or cohort, of participants are measured ontwo or more occasions.  Multiple cohortstudies permit researchers to examine the potential influence of ‘periodeffects’ (e.g., cultural factors specific to the period in which the study isconducted) on the outcome in question by assessing whether the longitudinalfindings generalise across different cohorts. 

See Cohort, Cohort effect, Longitudinal research, Longitudinal studies, Panel studies