Unit 1.4 : Tertiary Sources of Information

1. Introduction

Information is essential in our daily life for learning, research, decision-making, problem-solving, and entertainment. We share and receive information by speaking, writing, listening, reading, or through media like newspapers, television, and the Internet. Individuals and organisations create knowledge through experiences, observations, experiments, and studies. This knowledge is then recorded or communicated so that others can use it.
Information sources are the places, persons, or systems through which we obtain such knowledge. These may be documentary (recorded, like books and journals) or non-documentary (unrecorded, like experts or institutions). Information sources are the tools or channels through which facts, ideas, and knowledge are generated, preserved, and communicated for public use. The information sources are the foundation of education and research because they make knowledge available, preserve human achievements, and help solve personal, academic, and professional problems.

2. Meaning of Tertiary Sources of Information

Tertiary sources are created from both primary and secondary sources. They do not give subject information directly but guide users to where primary and secondary sources can be found. Their main function is as pointers or directories, helping users identify and locate valid documents.
IGNOU: "Tertiary sources are based on primary and secondary sources of information. They usually do not contain subject knowledge but provide a key to the primary and secondary sources."
ALA Glossary: "Tertiary sources are works based on primary and secondary sources used chiefly for identifying and locating documents."
Tertiary sources are not subject information tools but finding aids that guide users to primary and secondary sources. They are organised, time-saving, and essential for the quick and accurate location of documents.

3. Characteristics of Tertiary Sources of Information

• Based on Primary and Secondary Sources: They are created from information already available in primary and secondary sources. Example: A bibliography of bibliographies lists other bibliographies (secondary).
• Do Not Provide Subject Knowledge: Unlike encyclopaedias or research papers, they do not explain a topic. Their purpose is only to guide users toward other sources. Example: WorldCat tells you where a book is held, but does not give subject details.
• Locator Function: Their primary role is to act as pointers or maps that show what sources exist and where to find them. Example: A union catalogue tells which library has a particular journal.
• Organised and Systematic: They arrange information in a structured way (alphabetical, subject-wise, or title-wise) for easy use. Example: Ulrich’s Periodicals Directory lists journals by discipline and format.
• Helpful for Quick Search: They save time directly directing users to the right tool or source. Example: A guide to reference sources shows which dictionary or encyclopaedia is best for a subject.
• Regularly Updated: Many tertiary sources are revised or updated to reflect titles, publishers, or holdings changes. Example: Updated lists of serials or library catalogues.

4. Examples of Tertiary Sources of Information

Tertiary Source	Explanation	Example(s)
Directories	List of periodicals, organisations, publishers, or institutions; help users identify available sources.	Ulrich’s Periodicals Directory, Directory of Indian Libraries
Union Catalogues	Show combined holdings of multiple libraries, helping users locate where a book or journal is available.	WorldCat (global), IndCat (INFLIBNET, India), DELNET Union Catalogue
Bibliography of Bibliographies	Lists different bibliographies so users can find which bibliography covers a subject.	Winchell’s Guide to Reference Books, Bibliography of Bibliographies in Library Science
Guides to Reference Sources	Point out the best dictionaries, encyclopaedias, yearbooks, and other reference works in different subjects.	Guide to Reference Sources (ALA), Walford’s Guide to Reference Material
Lists of Serials and Periodicals	Provide details of journals, magazines, and newsletters with publication data.	International Serials Directory, Indian Science Serial Directory
Directories of Repositories / Databases	Point to electronic repositories, digital libraries, or databases.	OpenDOAR, ROAR, DOAJ (Directory of Open Access Journals)

5. Importance and Advantages of Tertiary Sources of Information

• Starting Point for Research: Tertiary sources guide primary and secondary materials. They help beginners know where to start when searching for information. Example: A guide to reference sources shows the best encyclopaedias and dictionaries for a subject.
• Save Time and Effort: Instead of scanning thousands of documents, users can consult one tertiary source that points to the right tool or document. Example: Ulrich’s Periodicals Directory helps identify whether a journal exists and where it is published.
• Provide Quick Access to Resources: They serve as maps of the information world, showing what is available and how to reach it. For example, WorldCat (union catalogue) tells which library has a particular book.
• Support Libraries and Collection Development: Librarians use them to decide which books, journals, or databases should be acquired for their collections. Example: Bibliography of Bibliographies helps libraries choose subject bibliographies for users.
• Assist in Resource Sharing: Union catalogues and lists of serials allow libraries to share resources through inter-library loan. Example: The DELNET Union Catalogue is used in India to borrow materials between libraries.
• Educational and Orientation Role: This role is beneficial for teaching students how to search, locate, and use information systematically. Example: Library orientation sessions often include training in using union catalogues and subject guides.

6. Limitations of Tertiary Sources of Information

• Lack of Original Content: Tertiary sources do not provide subject knowledge or new facts but point to other sources. Example: A union catalogue tells where a book is located, not its content.
• Dependence on Other Sources: They rely entirely on primary and secondary sources. If those are incomplete, tertiary sources are also weak. Example: A bibliography of bibliographies is useless if the bibliographies themselves are outdated.
• Risk of Being Outdated: Titles, publishers, and holdings change frequently, so tertiary tools must be updated. If not, they mislead users. Example: A printed list of journals may show titles that have ceased publication.
• Limited Usefulness for In-depth Research: They guide users where to go, but cannot provide detailed subject knowledge. Researchers must still consult primary or secondary documents.
• Possible Coverage Gaps: Some tertiary sources cover only specific languages, regions, or publishers, missing out on local or niche materials.
• Access Barriers: Many modern tertiary tools (like online directories or union catalogues) require subscriptions or institutional access, limiting availability.

7. Role of Tertiary Sources in Libraries and Learning

• Orientation and Starting Point for Research: Tertiary sources act as anchors for learners beginning their research. They provide overviews, context, and pointers to more detailed primary and secondary materials—making them invaluable tools for novices exploring new topics. Example: A student uses a library's Guide to Reference Sources to determine which encyclopaedias or databases are ideal for a research topic.
• Efficient Navigation Tools: They work like maps, guiding users through the vast primary and secondary literature landscape. Example: A union catalogue such as WorldCat shows which libraries hold a desired book, saving time and effort.
• Support for Library Collection Development: Librarians rely on tertiary sources to build and enrich their collections. These tools help evaluate crucial resources for acquisition or cancellation. Example: A bibliography of bibliographies assists in selecting the most influential works in a field.
• Facilitating Resource Sharing: Tertiary tools like union catalogues make inter-library loan and resource sharing possible by revealing where items are held. Example: In India, libraries use DELNET’s union catalogue to borrow materials from one another.
• Educational and Instructional Role: They're essential in library instruction—helping students learn how to research effectively by using directories, databases, and discovery tools. Example: Librarians introduce UG students to subject-specific indexes and encyclopaedia guides during orientation.
• Continuous Updates and Quality Control: Because tertiary sources are regularly updated, they help ensure access to accurate and current information pathways—though they must be managed carefully to avoid becoming outdated. Example: Updated directories reflect journal titles, publishers, and holdings changes.