Tutorial on Introduction to biostatistics
After determining the sample size the researcher then proceeds to collect data. Data can be gathered through primary or secondary sources.Primary Sources
Primary sources are original materials collected by the investigator himself. While collecting the primary data, the researcher can use the following methods.
· Personal interview
· Telephone interview
· Face to face administration of questionnaire
· Mailing questionnaire by post
· Mailing questionnaire by email
· Online data collection through websites
Each of the above methods has its advantages and limitations. A rule of thumb is to verify 5% of the data as a quality control measure to validate the data.Secondary sources
Secondary data is that which has been collected by individuals or agencies for purposes other than those of our particular research study. For example, if a government department has conducted a survey of, say, family health expenditures, then a health insurance company might use this data in the organization’s evaluations of the total potential market for a new insurance product.
Examples of secondary sources are
- Online databases
- Handbooks and manuals
- Review articles and editorials