Secondary research is the collection and collation of information that is published and publicly available. Also called desk research, it is frequently done to explore a topic before engaging in more expensive primary research, or to quickly gain a summary understanding of a topic without engaging too many resources. The advantages of doing secondary research (vs. primary research) are numerous. First, secondary research is considerably less expensive than primary research. There are two types of secondary data: external and internal. External secondary data is information gathered from outside the organization. This includes anything from government statistics to media sources. Internal secondary data is data that the organization is generating itself. Active secondary research takes place when the market researcher is dynamically searching for information. Government agencies generate large bodies of information that can be used by researchers. Most of this information is free to use, and can be useful at the start of a research project.