During the course of your research, you might be asked to use primary and secondary sources. 'What is the difference?', you ask.
•PRIMARY SOURCES "you will discover information first hand often by conducting interviews, surveys, or polls." Here you will be expected to collect and sift through "raw data." You will be expected to "study, select, arrange, and speculate on this data" The raw data may be opinions of experts, historical documents, theoretical speculations of a famous sociologist, or material collected from other researchers.
SECONDARY SOURCES here you will make use of secondary sources of information. These are published accounts of primary materials, for example the interpretation of raw data. "While the primary researcher might poll a community for its opinion of the outcome of a recent bond election, the secondary researcher will use the material form the poll to support a particular thesis"