Compare multiple cross sections over time hypack

Longitudinal studyДЄ longitudinal study, like a cross-sectional one, is observational. Therefore, we canвЂ™t know for sure if our daily walkers had low cholesterol levels before taking up their exercise regimes, or if the behaviour of daily walking helped to reduce cholesterol levels that previously were high. This is because such studies offer a snapshot of a single moment in time they do not consider what happens before or after the snapshot is taken. However, cross-sectional studies may not provide definite information about cause-and-effect relationships. We could, for example, look at age, gender, income and educational level in relation to walking and cholesterol levels, with little or no additional cost. The benefit of a cross-sectional study design is that it allows researchers to compare many different variables at the same time.

We would look only at cholesterol levels at one point in time. However, we would not consider past or future cholesterol levels, for these would fall outside the frame. We might even create subgroups for gender. To return to our example, we might choose to measure cholesterol levels in daily walkers across two age groups, over 40 and under 40, and compare these to cholesterol levels among non-walkers in the same age groups. Findings are drawn from whatever fits into the frame. Think of it in terms of taking a snapshot. The defining feature of a cross-sectional study is that it can compare different population groups at a single point in time. We would not influence non-walkers to take up that activity, or advise daily walkers to modify their behaviour. In our study, we would simply measure the cholesterol levels of daily walkers and non-walkers along with any other characteristics that might be of interest to us. This means that researchers record information about their subjects without manipulating the study environment. Cross-sectional studyД«oth the cross-sectional and the longitudinal studies are observational studies.

To make our choice, we need to know more about the benefits and purpose of each study type. The second requires a longitudinal study. The first approach is typical of a cross-sectional study. Do we want to compare cholesterol levels among different populations of walkers and non-walkers at the same point in time? Or, do we want to measure cholesterol levels in a single population of daily walkers over an extended period of time? One of the first things weвЂ™d have to determine is the type of study that will tell us the most about that relationship. LetвЂ™s say we want to investigate the relationship between daily walking and cholesterol levels in the body. In other words, knowing what kind of information the study should collect is a first step in determining how the study will be carried out (also known as the methodology). Study design depends greatly on the nature of the research question.

Compare multiple cross sections over time hypack