Which do you think would be the hardest type of longitudinal research to conduct – trend, cohort or panel? The easiest? Explain your reasoning.
A longitudinal study is a correlational research study that involves repeated observations of the same items over long periods of time. The hardest type of research would be collecting panel data because you are getting net change and gross change of the dependent variable. The easiest would be to collect trend data, which is why it is used so often in polls. A cohort sample could go either way because it may be hard to track the wide range of people that have the same characteristics over an extended period of time.
A cohort sample is a group that experiences some type of event (typically birth) in a selected time period, and studying them at intervals through time. Example: A group of graduates that are the same age from different colleges with the same degree are studied every 5 years on how they have progressed.
Panel studies measure the same sample of respondents at different points in time. Unlike trend studies, panel studies can reveal both net change and gross change in the dependent variable. A researcher can use either a continuous panel, consisting of members who report specific attitudes or behavior patterns on a regular basis, or an interval panel, whose members agree to complete a certain number of measurement instruments only when the information is needed.
A trend study samples different groups of people at different points in time from the same population. For example: Before an election a sample of adults is drawn. A year later, a different sample drawn from the same population shows a change.