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Conducting research


Sources come in three categories:  Primary, Secondary, and Tertiary.  This guide is designed to provide an overview of the various types and how they can be used in your academic work.  The tab Where to Search provides specific examples of sites to find each type.

Definitions and examples of types of sources

Primary Sources

Primary sources are created at the time of the events by people involved.  They include photographs, diaries, letters, newspaper articles, government documents, and a host of other items.  You create a primary source every time you send an email or take a selfie.  Primary sources are invaluable for understanding what people were thinking at the time and, therefore, understanding their motivation. 

When you use primary sources, you have to start by asking questions about the source itself.  It's important to consider who created the document and for what purpose, among other things.  Primary sources are as individual as the person creating them.  Just like you might write an email about what a rotten person Susan is, someone else might write about how great she is.  Similarly, newspapers and soldiers from different sides of a conflict are going to report differently about the same battle.

Most primary sources are easy to identify.  The only criterion is that it was created at the time of the events by someone involved in the events.  Historical documents of all sorts fall into this category and personal correspondence or diary entries are easily found online to support your research.  Use your keyword and add the words “primary source.”

Public documents fall into many categories.  Congressional voting records, treaties and contracts, police records, and policy statements are only a few the types of documents our government creates every day.  Don’t forget other governments as well.  Every country, current and historical, has a repository of documents.  Governments also come in a variety of levels including local, county, state, federal, and international.

Newspapers can be an interesting category.  The news is about drama.  They are not always interested in reporting the truth.  They are always interested in making money and “No New Information to Report” does not sell papers.  It is, however, often our only source of information and can be an accurate reflection of the standards and values of the time.  As with everything else, read media sources with an eye toward bias and try to compare multiple sources to get multiple perspectives.

Read the guide Where to Search to help learn how to select legitimate internet sources and determine the validity of a website.

Secondary Sources

Secondary sources examine a wide variety of primary sources and reach conclusions about them.  As an example, by comparing many points of view about a battle, including reports from the generals, letters home from the soldiers, and newspaper accounts, a broad and accurate view of the situation can be determined. 

Non-fiction works, especially books and journal articles, are usually considered secondary sources, but like everything else, you have to pay attention to ensure you are getting quality work.  In today’s market, it is easy to get published.  Amazon has a button you can press and put your work on the market.  No one has to read it or approve it or edit it in advance.  The author may have done little more than regurgitate a Wikipedia page and add some photographs.  More importantly, without academic editing, you cannot be sure of the accuracy of the facts.

To be sure a book is accurate, check to see that it comes from a University Press.  Another way is to check the sources of the book.  If the author did legitimate work, he will list his sources and you will be able to use them to check his work and to supplement your own.  Never use a source without sources.

Journal articles typically provide the thoughtful, analyzed information you are looking for.  There are many available in the school library database search.  The guide Where to Search explains in detail what you are looking for and how to access it.  The library is also happy to provide tutorials on getting the most out of the databases.

Tertiary Sources

Tertiary sources examine a variety of secondary sources and compile them into small bites.  These are lists, chronologies, dictionaries, and compilations such as encyclopedias.  You will find the same basic facts over and over again no matter how many of these you click into.  There will never be any substance and reading these is considered background, not research.  This is the way to answer trivia game questions about who and when.  If they list sources, as Wikipedia does, you might use those sources to find actual information. 

Most, such as your textbook, do not list sources.  While your textbook has many topics you may not be familiar with and may, therefore, seem complex, its purpose is to provide a broad overview of a subject.  That is why it mentions so many topics.  You will notice it does not go into great detail or depth on any particular topic.  The goal of a research project is not simply to list names and dates.  You have to understand the topic you are writing on enough to reach conclusions and be able to justify those conclusions with evidence.  That does not come from encyclopedia entries.

Tertiary sources have limited value in scholarly or professional work.  When you are beginning research on a topic reading a few tertiary sources will give enough of a general overview to identify the key players and events.  That is a good start in finding the keywords that you will use for the in-depth research.  Readings like this can be a good way to start, but quickly move into work with more substance.

Some sites that fit this category are Wikipedia, Thoughtco, Ancient History Encyclopedia, New World Encyclopedia, Ancient Origins.  Did you notice that most of those sites have the term “pedia” in them?  They are proud of their generic overview status.  That is what they do and some of them strive to do it better than anyone.  Some of them are very reliable.  You can certainly use the ones that are peer-reviewed to acquire your basic background information. 

The Ranger College library databases will often turn up Credo Research Starters in your searches.  These are encyclopedia-type articles that can provide some basic information and leads for deeper searches.  They have been approved as peer-reviewed so you know they are accurate, however they are tertiary sources.  Any encyclopedia is unacceptable as a source for collegiate level work, whether you get it from the school library or not.

Most are not peer-reviewed.  The worst site on the web is Quora.  You shouldn’t even consider clicking into or any other page like this.  Just stop.  Anyone, literally anyone, can answer a question.  Next time you are tempted, take a moment to look at something you know you are smart on.  You will be shocked at how awful the answers are.  Then realize they are just as wrong on answers you don’t know anything about.  Worse, there are trolls putting out bad information.  Don’t go there.

All of these encyclopedia pages are what are called Tertiary, or Third level sources.  The most you will get from them is basic, generic overview information such as places, dates, and some statistics. 

You should avoid using tertiary sources for anything beyond gathering ideas.  While there is a place for background in your work, your task is to delve deeper.  You need to understand the topics you are writing on a level that involves analysis and synthesis. 



Encyclopedias and textbooks are in red because these are the most problematic sources for students. 

Some items fall into multiple categories. 

Is a source primary or secondary?  It can sometimes depend on how a source is being used as to whether it is primary or secondary.  Charles Darwin's book on evolution, The Origin of Species is a primary source about Darwin and his methods of study but would be a secondary source when considering evolution.

Statistics are an interesting category.  They can be primary, secondary, or tertiary depending on how they are used.  They are a primary when considering the source contributors of the information.  Ten thousand mothers were asked…  Ten thousand black women…  Etc. because information gathering requires actual input.  This would only be used as a primary source when dealing with the raw data. 

The compilation of data into its components and lists is secondary.  When the number of police reports from a given city are accumulated and broken down into types of crime that is secondary.  All the information was analyzed from the primary source of criminal records. 

When a statistic is used in a source it becomes tertiary.  A website says that 70% of all mothers believe Pampers are better than Huggies.  The author of that article has extracted a piece of information and used it for his own purposes.  There may have been 1000 other pieces of information in that survey or set but only one met the criteria the author was looking for.  Without the whole set it is nothing more than a tertiary source. 

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