Observatiestudies

Observational studies involve carefully monitoring or observing events without attempting to influence the outcome.

There are three types of observational studies. Prospective studies look at the future, retrospective studies look at the past, and cross-sectional studies measure outcomes in a specific time period.

So, finding out how many liters of fuel a car would need to travel for the next 500 kilometers would be a prospective study.

On the contrary, retrospective or case-control studies are carried out in the present based on past data.

For instance, a group of patients suffering from chronic obstructive lung disease was selected and asked about their smoking history. A significantly high number of patients with a smoking history indicates the possible association between tobacco smoke and the disease.

A survey conducted by an army research group on the state-wise recruitment of army personnel would be a cross-sectional study. Here, the study is done for a specific period to find the number of soldiers from each state among the total recruits.