Information Sources and Resources

Please visit the links as you read through this page.

It's true that about anything can be a source of information. However, as we learn how to search and use information, it can be helpful if we focus on sources and their types. Doing so allows us to integrate different source types of information into our personal knowledge workflow.

Primary, Secondary, and Tertiary Sources

In general, it's helpful to classify information sources into three types: primary, secondary, and tertiary. Two of the main differences between these three types of information centers on the strength of evidence they provide and on their proximity to the topic they cover. Primary sources generally provide the strongest evidence on a topic and are also closer to the topic (i.e., more direct) than secondary sources.

This is useful to know. In fact, UK Libraries provides use cases for these three types and some definitions:

  • "Primary sources provide direct or firsthand evidence about a topic. The creator of primary sources is often intimately connected with the topic or event. Most often, creators of primary sources are participants in the events they describe, either directly or by virtue of living during the time period in question. Given this broad definition, primary sources comprise a wide range of resource types across the various disciplines" (Primary Sources).
  • "Secondary sources depend upon primary sources. Secondary sources describe, discuss, interpret, comment upon, analyze, evaluate, summarize, and process primary sources. The important thing to keep in mind when trying to decide if a source is primary or secondary is whether or not the author did the thing they are reporting on. If they did, it is a primary source; if they did not, it is a secondary source" (Secondary Sources).
  • "Tertiary sources contain information that has been compiled from primary and secondary sources. They organize information in an easily accessible way and often point the researcher to the primary and secondary literature on a given topic" (Tertiary Sources).

Let's expand on that a bit more:

  1. Primary Sources:
    • Research Papers and Studies: These are original research documents written by researchers or scholars. They include firsthand data, experiments, observations, and findings. For example, a scientific paper reporting the results of an experiment on the effects of cold water immersion on the human body would be a primary source.
    • Diaries and Personal Journals: Personal writings of individuals that offer insights into their thoughts, experiences, and daily life. For instance, a diary kept by a historical figure discussing their experiences during a particular period.
    • Interviews and Oral Histories: Recorded conversations with individuals who have firsthand knowledge of specific events or topics. This can include oral history interviews with people who experienced significant historical events.
  2. Secondary Sources:
    • Books: Books written by experts or scholars that analyze and interpret primary sources or provide an overview of a particular subject. For example, a book discussing the history of computing and the evolution of the command line since the 1970s.
    • Review Articles: Scholarly articles that summarize and analyze existing research in a particular field. They provide a synthesis of primary research findings.
    • Documentaries: Video or film productions that present information, often through interviews and visuals, to explain and explore a topic. Documentaries can be considered secondary sources when they provide analysis and context.
  3. Tertiary Sources:
    • Encyclopedias: General reference works that provide concise summaries and explanations of topics. They often compile information from various secondary sources. Examples include online encyclopedias or reference books.
    • Textbooks: Educational books designed for teaching a subject. They distill information from primary and secondary sources to provide structured knowledge on a topic.
    • Databases and Indexes: Online databases that organize and index primary and secondary sources, making it easier to search for relevant information. Examples include academic databases like PubMed, Academic Search Premier, or library catalogs.

We can summarize the above list and definitions into the following table:

Type of SourceDescriptionExamples
Primary SourcesOriginal firsthand accounts or data.- Research Papers and Studies
- Diaries and Personal Journals
- Interviews and Oral Histories
Secondary SourcesAnalysis and interpretation of primary sources.- Books
- Review Articles
- Documentaries (when providing analysis)
Tertiary SourcesSummaries and reference sources.- Encyclopedias
- Textbooks
- Databases and Indexes

Although the difference between these types is related to the strength of their evidence and their proximity to their topic, it's not helpful to think of this ordering as the way to search for information. As you learn how to locate information and conduct research, you will largely depend mostly on tertiary and secondary sources of information. For example, a reference work, like a dictionary, encyclopedia, a bibliographic database, or even a search engine, is considered a tertiary source but can be an ideal place to learn about a topic and to learn how to get primary or secondary information about that topic. We do not generally cite tertiary sources, like Wikipedia or Google, of information in our papers or other works, unless it seems important to do so.

Note however they we also do not plagiarize from these sources. If you do decide to use them as direct sources, then you need to cite them and quote them if you decide to use the text, etc that they provide.

Next, a book or a review article, as examples of secondary sources, can serve as a great summary, discussion, distillation, or commentary on a topic, and can also, in its discussion of a topic, provide references to more sources of information, which may be other secondary sources or even primary sources. For example, a scholarly book on censorship in public libraries should include references to research papers on that topic.

Finally, primary sources are sources that lie closest to the topic. As the table and list above indicate, they may include academic research, diaries, interviews, and more, much of which is based on or is the source of direct analysis. This type of information can often be the most difficult to read and interpret, because it may require extensive domain knowledge of the topic.

Primary, secondary, and tertiary sources say something about the kind of evidence in those respective sources. They are, in a sense, a ranking of the strength of their evidence about a topic. Primary sources provide the strongest evidence. However, when searching for information, it is often better to begin with tertiary sources.

Information Resources of Information Sources

In practice, these distinctions are important. If I do a library search, I have the option to narrow my search by Resource Type. These resource types, in conjunction with types of information sources, help us locate the information we need and identify the strength of that information. Example resource types in UK's catalog include:

  • Articles
  • Newspaper articles
  • Dissertations
  • Books
  • Book chapters
  • Review
  • Reports
  • Reference entries
  • Conference proceedings
  • Datasets
  • Maps
  • Images
  • Databases
  • Government documents
  • and more.

A resource is really a thing that supplies a thing, whatever that thing is. For our purposes, we can think of information resources as providers of information sources, like those listed above. One of the more important resources we can use are databases. Databases are great resources for locating sources of information. The term database itself is a bit problematic because it has multiple meanings, and I think it will help if we start this section by clarifying what we mean in this course by the term database.

According to the Dictionary of Information Science and Technology, the term database can be defined as:

a collection of files containing related information. Database consists of files and each file consists of records. Furthermore, each record consists of fields, which can be used to store the raw facts or data (p. 246).

This definition is not wrong, per se, but it is rather broad and therefore not entirely useful. For example, the definition entails that if I have a folder on my desktop, and if that folder contains only Excel spreadsheets on related content, and since those spreadsheets contain only records (i.e., rows) and fields (i.e., cells), then that folder on my desktop is a database. Although I suppose that's kind of true, I don't think that's really what the dictionary authors have in mind, and thus it's not an accurate enough nor a very useful definition.

A more specific and applicable definition is provided by the Online Dictionary of Library and Information Science, which defines a database as:

A large, regularly updated file of digitized information (bibliographic records, abstracts, full-text documents, directory entries, images, statistics, etc.) related to a specific subject or field, consisting of records of uniform format organized for ease and speed of search and retrieval and managed with the aid of database management system (DBMS) software. Content is created by the database producer (for example, the American Psychological Association), which usually publishes a print version (Psychological Abstracts) and leases the content to one or more database vendors (EBSCO, OCLC, etc.) that provide electronic access to the data after it has been converted to machine-readable form (PsycINFO), usually on CD-ROM or online via the Internet, using proprietary search software.

Most databases used in libraries are catalogs, periodical indexes, abstracting services, and full-text reference resources leased annually under licensing agreements that limit access to registered borrowers and library staff. Abbreviated db. Compare with data bank. See also: archival database, bibliographic database, embedded database, metadatabase, and niche database.

The above definition is more helpful because it provides examples of content type (e.g., bibliographic records, abstracts, full-text documents, etc) and how to access that content (e.g., library catalogs, periodical indexes), because it partitions out the components of a database (records, search, retrieval), and because it distinguishes a database proper from a database management system (DBMS), which is what the prior definition was attempting to define. The ODLIS definition also highlights the role of database producers in producing databases (e.g., the American Psychological Association), which tells us something about the subject matter of a database (e.g., psychology).

What are example databases?

The ODLIS definition provides some leads to this question. The definition tells us that example databases include "digitized information containing bibliographic records, abstracts, full-text documents, directory entries, images, and statistics" that are "related to a specific field or subject," and that these can be accessed through library "catalogs, periodical indexes, abstracting services, and full-text reference resources." Given that, let's look at some examples.

Library Catalogs and Discovery Services

We'll start with the most general example, and that's the library catalog. Traditionally, library catalogs are databases that primarily provided information about where we could find content on a library's shelves (i.e., print content). However, given that more content is available online, nowadays these catalogs are more often referred to as discovery services. In this expanded role, not only can they tell us where to find a book on a shelf, but they can also provide full text access to online content in other databases.

We can access the University of Kentucky's library catalog/discovery service at their main website at:

Please visit the link and test your own searches.

In the center of UK Libraries' homepage, we find several links of interest: the InfoKat (Books and More) link, the Database link, and the Journals link.

InfoKat searches bibliographic records. It does not provide full text access. Instead, they provide access by linking to content or by providing physical directions to that content. For example, if that content is a print item someplace on the library's shelves, InfoKat might tell us it's located on the 5th floor of WT Young and has the call number Z674.82.159 S42 1996, or something like that. However, if that content is online, then InfoKat should give us a direct link to it. It could also be that the InfoKat has records for information sources but not the actual sources themselves. In those cases, the bibliographic records should provide a link to request the item through interlibrary loan (ILL).

Google and other search engines function in much the same way. If I do a search for the term databases in Google, the search engine will return results to sites that are relevant to that term, like a Wikipedia article on databases. Google itself does not store the full text content and only provides access (i.e., links) to content based on its own indexing of where things are on the web. Unlike the library's catalog, if Google returns results for pages it cannot access or that don't exist anymore, there is no ILL service offered, and we're left to our own devices to find access to that information.

Periodical Indexes and Abstracting Services

InfoKat returns a wide variety of bibliographic records that describe and provide access to books, ebooks, book chapters, maps, scholarly articles, news articles, images, and more. InfoKat is therefore great as a discovery service because it functions as a kind of catchall for all the types of works that a library can provide access to, as just listed. However, there will be times when we will want to focus our search to a more limited subset of records, such as those that produced by periodicals.

Periodicals are nothing more than magazines and journals. This kind of genre produces issues at regular (or even at irregular) intervals, such as weekly, bimonthly, monthly, or quarterly issues, with no pre-determined end. Periodicals focus on different audiences, such as the general public (e.g., Time magazine), parts of the general public (e.g., WIRED, Elle, Better Homes and Gardens), the general scholarly community (e.g., Nature, Science), or to specific scholarly communities (e.g, Journal of Information Technology, Journal of Synchrotron Radiation, Journal of Sociology). Scholarly journals are generally (but not always) peer-reviewed journals, which means that when authors submit their manuscripts to these journals, the manuscripts are sent out to two to three peers in the scholarly community who read the manuscripts and write recommendations to the editors for improving the manuscript, or who recommend that the journal editor reject the manuscript. Different journals and different scholarly disciplines have different criteria for making judgments on quality.

There are two broad ways to locate sources in periodicals. At the UK Libraries homepage, we can select the Journals link or the Databases link. The Journals link lets us search for specific journal titles and, if desired, within disciplinary/subject categories (e.g., Health & Biological Sciences, Law, Politics & Government, Language & Literature, or Social Sciences, Journalism & Communications, and more). Once we locate a journal of interest, we can visit the link and then search within that journal or peruse the table of contents for specific issues.

The Databases link lets us expand our search of records to broader categories or subject areas of periodicals. Here we find databases like Academic Search Complete, which will let us search thousands of periodicals, including magazines and scholarly journals, across a range of subject categories. JSTOR is another database that indexes a broad subject range of periodicals but with greater emphasis on peer-reviewed material. Databases may also have a specific focus. For example, the African American Communities database provides access to archival and historical papers, oral histories, essays, letters, pamphlets, and newspapers on African American communities and is geographically focused on Atlanta, Chicago, New York, and parts of North Carolina. Then we also have access to databases like the Kentucky Building Code, which is a database that links to residential and commercial regulatory information on building, plumbing, design in Kentucky.

Many of the resources listed above, as well as the hundreds that UK Libraries offers and that I have not described, provide access to full-text content. But this isn't necessarily so. All that a periodical index must offer to be classified as such are records that contain basic information, such as article titles, author names, publication names, publication date information, and often subject terms. Abstracting services provide the same information but also provide abstracts of journal articles, which are searchable. Since abstracts provide summary information of the main articles, this is helpful in locating information sources.

Full-text Resources

Since periodical indexes and abstracting services do not necessarily provide direct full text access, you might wonder what the point is if you can't get the full text of some source that the library tells you exists. The point is that even if the library doesn't have immediate access to a source, if it can tell you that it exists, then a librarian can likely get the source through interlibrary loan (which is fast!) or some other means. So if the stakes are high (e.g., you are a cancer researcher) and you really need or just want information (e.g., about a cancer therapy), then periodical indexes and abstracting services are great resources even if they do not provide immediate full text access.

That said, in addition to a variety of periodical indexes and abstracting services, UK Libraries provides quite a few full text databases. Visit the A-Z Databases page to see all of your choices. A full-text database may also be an abstracting service, if it provides the basic information listed above (title, author name, etc) about periodical content. It becomes a full-text abstracting database if it also provides access to the full-text source. Other non-periodical database, like the African American Communities database, also provides full text access to its sources, and may even be thought of as a digital library and not just a database.

In the next few paragraphs below, I will focus on a few general purpose full-text databases that you may find helpful as you work towards your degree. Although these databases provide full-text sources, they may not provide full-text to everything they have records for, though.

Academic Search Complete

Academic Search Complete (ASC) is a database of databases. It can search over 60 different databases and indexes, each including hundreds of journal titles, including:

  • Communication and Mass Media Complete
  • Sociological Collection
  • Music Index
  • SPORTDiscus
  • eBook K-8 Collection,
  • and more.

In ASC, we can search all 60 plus databases at one time, or we can select one or more of them, which might make better sense. For example, if we were interested health related information, we might want to search the following ASC databases at once:

  • Consumer Health Reference eBook Collection
  • Health and Psychosocial Instruments
  • APA PsycInfo


Like ASC, ProQuest provides access to many subject based databases, and also, many of the database topics overlap. ProQuest uses this to highlight database collections. For example, the SciTech Premium Collection includes three databases that can be searched at once. These include the:

  • Natural Science Collection
  • Science Database
  • Technology Collection

ProQuest's Social Science Premium Collection includes databases on criminology, education, library and information science, politics, sociology, and more.

ProQuest also provides database access to magazines and news content, including The Vogue Archive and various current and historical newspapers, such as an archive of The New York Times or current issues of The Courier-Journal (Louisville, KY).


JSTOR is another multi-disciplinary database. JSTOR covers subjects such as:

  • Arts
  • Business & Economics
  • History
  • Medicine & Allied Health
  • Science & Mathematics
  • Security studies
  • Social Sciences, and more.

Each of these subject areas includes access to many journal titles, and therefore, many journal articles. JSTOR has long focused on back issues of journals, but in recent years has made moves to include current literature and open access content (this content that is freely available). JSTOR also includes ARTSTOR, a database of images, video, and other multimedia content, much of which is also available as open access.

Note: Open access (OA) content is content that is freely available to access. That does not, however, mean that the content is free of copyright protections. There are different types of OA copyright licenses and each will stipulate how we can use that content. provides a list of some of the more popular licenses and what the mean for us. In all cases, though, if you use OA content, be sure to attribute it with source information.


Remember, one of the main ideas of this course is that there are many sources of information that are not easily available via Google or some other search engine. Even when we do use Google or Bing or Yahoo or something else, there are certain advanced tricks we can use to leverage them to find better information. We'll cover those soon. Regardless, if we apply what we'll learn in this class, we'll become that much more accomplished.

In short, we are going to learn a bit more about what's hidden from most users and from the common view. To do that, we needed to understand the difference between information sources and information resources. Information sources can be divided into three types: primary, secondary, and tertiary. The differences among them center around the strength of the evidence they provide and their proximity to their topic. However, when searching for information, it is often better to begin with tertiary and secondary sources. In the end, in information source is the main item we often aim to acquire.

An information resource is a tool that provides or supplies access to information sources. In this section, some examples of information resources are the library discovery service, a search engine, and a database like JSTOR, ASC, or ProQuest. These are all tertiary sources that can lead us to more substantial sources of primary and secondary information.