# Different Types of Statistical Studies

It is important to correctly identify different types of statistical studies. Broadly speaking there are two different types of studies - **observational **and **experimental**. Some of these studies are **retrospective **(where data are observed or recorded on variables of interest from events that have already occurred). Some studies are **prospective** (where data are observed as they happen, as in medical studies). Such studies can be **longitudinal **(where data are studied across a time period) or **cross-sectional **(where data are studied at a particular point of time).