Some examples of descriptive research include case studies and preliminary observation of a group. Case studies are examples of a relevant event that can be analyzed to learn about a specific group or topic. Observation is an essential part of descriptive research, and is the main way of gathering information.
Descriptive research includes both quantitative and qualitative data and uses these types of data to describe the population being observed. For example, someone interested in why certain groups of trees are dying, while others of the same type and in the same location are thriving, can observe the trees and their surrounding environment to come to a preliminary decision. At its core, this is descriptive research.
Descriptive research is mostly used in the beginning of researching a topic or phenomenon. Observation provides the initial information needed for the researcher to form a hypothesis about the topic. Someone who is studying the effects of a river on wildlife can observe the wildlife near and far from the river to come up with a few basic ideas about how the two items are connected. This information is valuable as the research moves into is next steps, where experiments find more provable, concrete data.