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Research Essentials

How to Find Sources

In libraries and on the Internet you can find books, magazines, encyclopedias, lab reports, historical documents, audio and video recordings, and all sorts of other information sources, all of which are useful for different purposes. Deciding which will suit your purpose is an important early step in the research process.

Three basic types of resources:

To know where to go for information, it is useful to know how information is produced; here is a very general overview. (note that these are not rigid distinctions; the same resource can overlap categories.)

  • Primary - Direct, uninterpreted records of the subject of your research project. A primary source is as close as you can get to the event, person, phenomenon, or other subject of your research. As such, a primary source can be almost anything, depending on the subject and purpose of your research. For example, if you are writing about a novel, the novel is a primary source, and an article critiquing the novel is a secondary source to help you construct your own interpretation of the novel. If you are writing about the critical reception of a novel, that article critiquing the novel is a primary source. Or, a published version (or even a translation) of a diary, if it is a reliable representation of the actual diary, is for many (but not all) purposes sufficient as a primary source. So be creative in thinking of possible relevant primary sources of information on your topic.
    To make things even more confusing, 'primary source' means something different in science and in humanities (and can go either way in social sciences). In science, an academic journal article presenting the results of a researcher’s original experiment is a primary source. But in the humanities, a journal article is a secondary source which presents the results of the researcher’s analysis and critique of primary sources (such as a novel, a painting, a song, ...).
  • Secondary - Books, articles, and other writings by scholars and researchers build on primary sources by interpreting and assessing primary information.
  • Tertiary - Encyclopedias, indexes, textbooks, and other reference sources which present summaries of or introductions to the current state of research on a topic, or provide a list of primary and secondary sources of more extensive information.

Work backwards. Usually, your research should begin with tertiary sources:

  1. Tertiary - Start by finding background information on your topic by consulting reference sources for introductions and summaries, and to find bibliographies or citations of secondary and primary sources.
  2. Secondary - Find books, articles, and other sources providing more extensive and thorough analyses of a topic. Check to see what other scholars have to say about your topic.
  3. Primary - A primary source on its own is likely only a snippet or snapshot of the full picture; thus it is often difficult to interpret on its own. Reference sources and secondary analyses give you a framework for interpreting primary sources. But the real work of research is examining primary sources to test the interpretations, analyses, and views you find in reference and secondary sources. Now that you have a solid background knowledge of your topic, you are better able to understand, interpret, and analyze the primary source information. Use primary sources to find evidence which challenges these interpretations, or evidence in favor of one scholar's interpretation over that of another; then posit an interpretation of your own, and look for more primary sources for evidence to confirm or refute your thesis. When you present your conclusions, you will have produced another secondary source to aid others in their research.

Here's a brief list of some of the sources you can find in each of these categories; remember, there are many more:


  • Conference proceedings - Scholars and researchers getting together and presenting their latest ideas and findings
  • Books - Extensive and detailed discussions of a particular topic or set of topics, written by the scholars and researchers who came up with the ideas or discovered the findings.
  • Journal articles - Brief, specific analyses of particular aspects of a topic, written by the scholars and researchers who came up with the ideas or discovered the findings.
  • Lab reports - Experiments, observations, etc.
  • Works of art ("art" broadly defined) - Novels, stories, paintings, sculptures, songs, ... pretty much any product of human artistic endeavors that someone decides is worth critiquing or analyzing.
  • Historical documents - Official papers, maps, treaties, etc.
  • First-person accounts - Diaries, memoirs, letters, interviews, speeches
  • Recordings - audio, video, photographic
  • Artifacts - manufactured items such as clothing, furniture, tools, buildings
  • Newspapers - Some types of articles, e.g. stories on a breaking issue, or journalists reporting the results of their investigations.
  • Government publications - Census statistics, economic data, court reports, etc.
  • Internet - Web sites that publish the author's findings or research; e.g. your professor's home page listing research results. Note: use caution when using the Internet as a primary source … remember, on the Internet a page citing authoritative findings could have been published by any goofball off the street.
  • Manuscript collections - Collected writings, notes, letters, diaries, and other unpublished works.
  • Archives - Records (minutes of meetings, purchase invoices, financial statements, etc.) of an organization (e.g. The Nature Conservancy), institution (e.g. Wesleyan University), business, or other group entity (even the Grateful Dead have an archivist on staff).
  • Books - collections of historical documents, first-person accounts, archival materials, and other primary sources, compiled and edited by a scholar and published together in a book.


  • Books - Extensive and detailed analyses by scholars providing criticisms, commentaries, and interpretations of primary ideas and findings.
  • Journal articles - Brief, specific analyses, criticisms, commentaries, and interpretations of particular aspects of primary ideas and findings.
  • Newspapers - Articles which report on earlier findings, or offer commentary or opinions.
  • Internet - Web sites that comment on earlier findings or research; see cautionary note above!


  • Encyclopedias - Articles providing introductory or summary information; coverage can be general (e.g. Encyclopedia Britannica) or subject-specific (e.g. Encyclopedia of Sociology).
  • Dictionaries - Definitions or brief summaries of terms, ideas, etc.; coverage can be general (e.g. Webster's, Random House) or subject-specific (e.g. Dictionary of Cell Biology).
  • Almanacs - Good for concise factual information, e.g. statistics, lists
  • Directories - Lists of people or organizations, with addresses, affiliations, etc.; useful guides to finding primary source material
  • Atlases - Maps of population, economic, historical, political, geological, biological, climatological, etc. information.
  • Indexes - Lists of sources on a subject or set of subjects; once you have some key terms for your topic, use indexes to find secondary and primary sources.

Places to look:

OneSearch – A good starting point. Covers most, but not all, of Wesleyan library’s online and physical resources, including the library collections at Wesleyan (and also at Trinity and Conn College – you can place a request to have a Trinity or Conn item sent here for you) and most of the indexes and databases the library subscribes to. It does not search WorldCat.

Databases – Select a database by specific discipline or type or source for a more focused search than OneSearch offers, and often with specific functionality not available in OneSearch.

Credo Reference – A large collection of published academic reference sources (encyclopedias, dictionaries, etc.), or select from a list of subject specific online reference sources.

WorldCat – Most books in most libraries in the United States and many libraries elsewhere; if a book has been published and cataloged by libraries it is most likely listed in WorldCat. This includes many titles not in Wesleyan’s collection and thus not included in OneSearch. If a book in WorldCat is not at Wesleyan, Trinity, or Conn College, you can place an interlibrary loan request for a copy.


If you are looking for:

  • A specific book (or audio/video recording or other specific known item): use OneSearch to find whether it is available at Wesleyan, Trinity, or Conn College. Limit your search to “Wesleyan” or “CTW” to avoid getting book reviews and other articles in your results. For books not available at a CTW library, you can use WorldCat, which allows you to place an interlibrary loan request for it.
  • A specific article: use OneSearch to see if the library has access to the article (to make sure the record for the article shows up at or near the top of the results list, put quotes around the title to search it as a phrase, and add the author's name and/or the title of the journal). Or, use the Journal Locator to see if the library has access to the journal (search for the title of the journal).
  • A specific topic: OneSearch is a good place to start. Enter a few keywords to describe your topic, then you can narrow and specify the results using the facets on the left of the screen (limiting to peer reviewed sources, sources in a particular discipline, reference sources, etc). Or, you can look through the list of Databases to find an appropriate subject specific index of publications

Here are some strategies for quickly and accurately broadening, narrowing, or refining your search results. Most online indexes and databases have at least some of these options, but there are often differences in how to use them, so read the help screens for the database you are using. Many of these techniques are demonstrated in this video on Getting the most out of OneSearch


Keyword vs.

Broader /
Narrower /

Related Terms




Item Type




Precision and Recall

But first, a little searching theory, to see how these techniques can be useful. When you search an online database, you want to find as much relevant information in the database as you can while avoiding getting irrelevant items along with your results. 

Precision – how much of the information your search retrieved is actually relevant to your needs. If your search retrieves a lot of irrelevant results, you can use some of the techniques below to make a more precise search.

Recall – how much of the relevant information in the database you were able to find with your search. This is much more difficult to determine: you don't know how much useful information your search didn't find. By using some of the techniques below to increase recall, you can be more confident you have found at least most of the useful information in the database. 

Increase precision by being very specific and narrow in your search, which will give you few if any irrelevant results, but that risks missing some useful information. Increase recall by broadening your search and thus finding more useful information, but that tends to increase the "noise" (irrelevant results) in your results.

If you need just a few good results, focus on increasing precision: it doesn't matter if you don't find everything relevant, and you don't want to wade through lots of irrelevant results. But for a full literature review for a big research project, you need to find as many relevant articles as you can, so focus on increasing recall even if you have to sort out a lot of irrelevant results.  



Keyword vs. Subject Searching

Keyword – searches everywhere in a source: title, author, abstract, full text, etc. Retrieves all sources which have that term anywhere in any context, but does not find synonyms of the term. Usually finds more results, but also more irrelevant results.

Subject – searches subject tags selected from a database’s list of standardized subject headings. Retrieves only sources tagged with that subject heading, but includes sources in which the author used synonyms other than the actual subject heading. Usually finds fewer results, but more of the results are relevant.

Start with keywords: think of different terms and phrases to describe your topic and search for them. Pick the best results and see what subject headings are tagged to them, then use those subject terms to find more sources like them.

Searching for ‘Shakespeare’ as a keyword (“any field”) will find results where Shakespeare is the author, a major subject, or briefly mentioned. Searching for ‘Shakespeare’ as a subject finds only results where Shakespeare is a major subject.

Searching for ‘elderly’ as a keyword will find results with that term anywhere at least once and in any context (e.g. elderly trees), but will not find results that talk about ‘senior citizens’, ‘aged’, ‘geriatric’, or other synonyms. Searching ‘elderly’ as a subject (if it is a subject heading) will find results where elderly people are a main subject regardless of what synonyms the author used.



Broader / Narrower / Related Terms

If you do not find enough information on your topic, think of synonyms or other ways of stating your topic and do another search. Or, use more general terms to broaden your search.

If you find too much information on your topic, add more terms or use more specific terms to narrow your search, or use synonyms or related terms to refocus your search.

Databases that use subject headings often include a thesaurus of broader, narrower, and related terms for their subject headings, along with what they mean by the term and what synonyms it includes.



Boolean Searching

Use AND, OR, and NOT search operators to combine two or more terms. This allows you to define a complex set of search criteria in a single search.

AND - Finds records in the database with all of your search terms; i.e., AND narrows a search and makes it more specific, finding sources which are about both of two different topics.


Find only those records in the database which include both terms 'dogs' and 'cats' somewhere in the record.

OR - Finds records in the database with at least one of your search terms; i.e., OR broadens a search, finding sources which include one or the other (or both) of two different terms.


Find all records in the database which are about either dogs or cats, including those sources which are about both dogs and cats.

NOT - Excludes records which have a specified search term from your results; i.e. NOT narrows a search, eliminating a subset of sources from a larger set.


Find sources on anything about dogs except for things also about cats.

Complex searches - You can make very complex searches by using more than one operator in a search:


Find sources about food for pets other than cats and dogs.



Broaden a search by searching for variant endings of a word.

For example, to search for computers, computerization, etc., type "comput*". You will retrieve everything in the database on computers, computing, computerize, computerization, etc. Some databases also have "wildcard" symbols, to search for variant spellings within a word. For example, "lab*r" would find 'labor' and 'labour'.




Note: Different databases use different keys for truncation and wildcards (usually * or $ or ?) so check the help guide for each database you use.


Use quotes around a string of words to search them as a phrase rather than as separate keywords.

The terms ‘population’ and ‘fund’ are likely to show up somewhere in other documents about the United Nations; using quotes will narrow your results to only those documents about the United Nations Population Fund specifically.

Phrase searching is also useful when your phrase contains "stop words," common words such as 'a', 'an', 'the', 'of', etc, which are usually ignored by search tools. By using a phrase search, you can search for the entire phrase, stop words included:


Item Type

Narrow your search by specifying just one type of source to find, e.g. books, articles, images, sound recordings ...

Another common option is to limit your search to find only peer reviewed articles, i.e. articles in academic journals which are reviewed by other scholars and researchers in the field before they are published to check for accuracy and importance of contents. 



Specify that two or more terms must appear close to one another, e.g. "adjacent" to each other (in any order), "within" the same sentence or paragraph, or "near" (e.g. within 5 words of) each other. This is especially useful for searching full text databases.

This search limits results to articles with 'diabetes' and 'children' within 5 words of each other:

Specific commands for proximity searching vary between databases, so consult each database's help screens.