Secondary Sources in Research

In contrast to primary sources in research activities, secondary sources consist of information that has been gathered and often interpreted by other researchers and recorded in books, articles, and other publications. 

In her "Handbook of Research Methods," Natalie L. Sproull points out that secondary sources "are not necessarily worse than primary sources and can be quite valuable. A secondary source may include more information about more aspects of the event than did a primary source."

Most often though, secondary sources act as a way to keep up with or discuss progress in a field of study, wherein a writer may use another's observations on a topic to summarize his or her own viewpoints on the matter to progress the discourse further.

The Difference Between Primary and Secondary Data

In the hierarchy of the relevance of the evidence to an argument, primary sources like original documents and first-hand accounts of events provide the strongest support to any given claim. By contrast, secondary sources provide a type of back-up to their primary counterparts.

To help explain this difference, Ruth Finnegan distinguishes primary sources as forming the "basic and original material for providing the researcher's raw evidence" in her 2006 article "Using Documents." Secondary sources, while still highly useful, are written by someone else after an event or about a document and can therefore only serve the purpose of furthering an argument if the source has credibility in the field.

Some, therefore, argue that secondary data is neither better nor worse than primary sources—it's simply different. Scot Ober discusses this concept in "Fundamentals of Contemporary Business Communication," saying "the source of the data is not as important as its quality and its relevance for your particular purpose."

Advantages and Disadvantages of Secondary Data

Secondary sources also provide advantages unique from primary sources, but Ober posits that the major ones are economic saying that "using secondary data is less costly and time-consuming than collecting primary data."

Still, secondary sources can also provide hindsight to historical events, providing the context and missing pieces of narratives by relating each event to others happening nearby at the same time. In terms of evaluations of documents and texts, secondary sources offer unique perspectives like historians have on the impact of bills such as the Magna Carta and the Bill of Rights in the U.S. Constitution.

However, Ober warns researchers that secondary sources also come with their fair share of disadvantages including quality and scarcity of sufficient secondary data, going so far as to say "never use any data before you have evaluated its appropriateness for the intended purpose."

A researcher must, therefore, vet the qualifications of the secondary source as it relates to the topic—for instance, a plumber writing an article about grammar may not be the most credible resource, whereas an English teacher would be more qualified to comment on the subject.