The four sources of research are primary sources, secondary sources, tertiary sources, and quaternary sources.
Primary sources are first-hand accounts of events or direct observations and interpretations of a particular phenomenon. This can include interviews, surveys, field notes, case studies, and experiments. These sources provide a direct understanding of a topic, but they can be difficult to obtain and often require a certain level of expertise to properly interpret.
Secondary sources are accounts of events or phenomenon that have been produced by someone other than those directly involved. Examples include books, articles, and reviews. These sources provide a more comprehensive view of a topic, but they are not as reliable as primary sources and can sometimes be biased.
Tertiary sources are summaries of primary and secondary sources. These sources are useful for providing an overview of a topic, but they lack the detail and accuracy of primary and secondary sources. Examples include encyclopedias, textbooks, and websites.
Quaternary sources are sources that provide access to primary, secondary, and tertiary sources. This can include libraries, online databases, and digital repositories. These sources are useful for finding relevant information on a particular topic, but they often require a certain level of expertise to navigate.
Overall, the four sources of research provide a range of information on a given topic. Primary sources provide a direct understanding of a topic, secondary sources provide a more comprehensive overview, tertiary sources provide an overview of primary and secondary sources, and quaternary sources provide access to primary, secondary, and tertiary sources.