How to Categorize Information Sources by Content

When you start a research task, one of the first questions you face is not just where to look, but what kind of source actually holds the answer you need. A quick fact about the French Revolution, the latest findings on a new drug molecule, and the technical details of a battery design all live in very different places. This is where categorising information sources by their content becomes a practical skill. Instead of treating every source as interchangeable, you learn to match the type of content to the type of question. The result is faster, more accurate research and far less wasted time chasing the wrong material.

What content-based classification of sources means 🔗

Information sources can be grouped in many ways: by physical form, by how original the information is, or by the audience they serve. Content-based classification takes a different angle. It groups sources according to the specific type of subject matter and treatment they offer. As one library science overview puts it, this approach is like sorting a bookshelf by the topics each book covers rather than by genre.

The intellectual work of assigning a document to a category has long been the core concern of library science, while computer science approaches the same problem algorithmically. The field of document classification sits at the meeting point of these disciplines, and the documents being sorted can be texts, images, music, and more. For the purposes of this discussion, we focus on the human, content-driven view: what is the source about, and how deeply does it treat that subject?

Three broad content bands cover most academic and reference needs. The first is general information, meant for broad understanding. The second is scientific or scholarly content, meant for academic depth. The third is technical content, meant for precise, applied detail. These bands overlap at the edges, but each one answers a distinct kind of question.

General information sources 🔗

General information sources provide broad, non-specialised knowledge across a wide range of subjects. They are written to give a reader a quick and reliable overview, which makes them excellent starting points before deeper research begins. The treatment is summarised rather than exhaustive, and the language is accessible to a non-expert.

Encyclopedias and reference works 🔗

The classic example is the encyclopedia. An encyclopedia is a collection of summaries on selected key concepts within a field, and scholars often reach for one as an initial resource when approaching an unfamiliar topic. A general work such as the Encyclopaedia Britannica offers dependable overviews across history, science, and culture, while subject encyclopedias narrow the focus to a single discipline. Dictionaries, handbooks, yearbooks, and directories fall into the same family of broad reference content. Notably, encyclopedias are usually treated as tertiary sources because they compile and condense information that originally appeared elsewhere.

The strength of general sources is orientation. They help you grasp key ideas, learn the important terminology of a field, and identify the names and concepts you will later search for in more specialised material. Their limit is depth. An encyclopedia entry will rarely contain the level of detail a serious research project demands, and it is not where new knowledge first appears.

Scientific and scholarly sources 🔗

When a question moves from “what is this topic” to “what does the current research actually show,” the content band shifts to scientific and scholarly sources. These carry academic content produced and reviewed by experts, and they are the engine of new knowledge in any discipline.

Scholarly journals and articles 🔗

The scholarly journal is the central source here. These journals contain articles written by experts in an academic field, often covering very specific topics, and they typically include bibliographies that point to related work. What sets a scholarly journal apart from a magazine is the review process. Before research results appear in a scientific journal, they must pass a rigorous review by other scientists known as peer review. This vetting is why journal content is treated as authoritative.

It helps to know the difference between two common article types. A research article tells you exactly how a scientist performed an experiment and interpreted the results, while a review article gives an overview of the state of a field over a period of time. Review articles are useful for getting your bearings within a discipline, but they date quickly, so the publication year matters.

Where journals sit among source types 🔗

The original journal article reporting fresh experimental results is a primary source in the sciences, alongside conference proceedings, theses, and lab notebooks. By contrast, textbooks and encyclopedias that compile and synthesise that research are considered the secondary or tertiary literature. This is worth keeping in mind because the same broad label, “scientific source,” can sit at different distances from the original discovery depending on how the content was produced.

Technical sources 🔗

Technical content is precise, applied, and often tied to a specific invention, process, or product. It answers questions about how something is built, how it works, or what rules it must meet. Two source types dominate this band: patents and standards.

Patents as technical sources 🔗

A patent is a public notice of an invention filed with a government patent agency, and it grants the inventor exclusive rights to the creation for a set period, usually around twenty years. The crucial point for researchers is that a patent document carries detailed technical information about a given technology, often described in a way that exists nowhere else. Companies frequently choose to file patents rather than publish in journals precisely because the patent secures exclusive use, with the result that a large share of patent literature is published in no other format.

In the Indian context, patents are administered through the Indian Patent Office, and inventors are expected to run a prior-art search before filing. The official inPASS portal lets users review existing patents, legal status, and bibliographic details to confirm whether an invention is genuinely novel. Patents also work as research tools beyond legal filing: professionals use them for mapping the current state of science and technology and for competitive analysis. Historical Indian patent documentation, such as the abridgments of specifications issued by the Patent Office, remains valuable for tracing how specific technologies developed over time, as documented in the documentary sources on Indian patents.

Standards as technical sources 🔗

Standards are another technical content type, specifying agreed protocols, dimensions, and quality benchmarks. In India, these are published by the Bureau of Indian Standards, an agency set up in 1987 to devise uniform quality standards for manufactured and agricultural goods, conduct product testing, and license the certification mark. The BIS is the successor to the older Indian Standards Institution, the body behind the familiar ISI mark. Many Indian Standards are aligned with or technically equivalent to international ISO and IEC standards, as noted in research on intellectual property and ICT standards in India. For an engineering student or a manufacturer, a standards document is the authoritative content source on what a product must achieve to be considered compliant.

Why content-based categorisation matters 🔗

The practical payoff of this classification is targeting. Once you can read a question and sense which content band holds the answer, your search becomes precise. If you need a quick orientation, you reach for a general source. If you need vetted academic findings, you go to a scholarly journal. If you need the build specifications of a device or the rules it must satisfy, you consult patents and standards.

A simple matching habit helps. For broad background, a book or encyclopedia is the right call; for scholarly findings, a journal; for current events, a newspaper or reputable website. This kind of deliberate source selection depends on your topic, the type of information you need, and what is available to you. Choosing the wrong band wastes effort, because an encyclopedia will never give you patent-level technical detail, and a patent will never give you a gentle overview of a field.

Content-based categorisation also protects accuracy. When you deliberately route a scientific query to peer-reviewed material rather than a general website, you raise the reliability of what you find. For students managing research projects and for librarians guiding users, the ability to match content type to information need is what turns a scattered search into an efficient one. It is the difference between knowing that information exists and knowing exactly where to find the right kind of it.

What do you think? Which content band do you reach for first when starting a new research task, and has it ever sent you to the wrong type of source? How might your search habits change if you matched each question to its content category before you began?

References

1. https://en.wikipedia.org/wiki/Document_classification
2. https://libguides.fau.edu/c.php?g=325509&p=2182110
3. https://courses.lumenlearning.com/atd-tc3-academicwriting1/chapter/primary-secondary-and-tertiary-sources/
4. https://library.csus.edu/guides/metzgerd/Bio1/TypesofArticle.pdf
5. https://guides.library.upenn.edu/c.php?g=476231&p=3256057
6. https://guides.library.upenn.edu/c.php?g=475415&p=3254413
7. https://www.diligencecertification.com/indian-patent-search/
8. https://www.sciencedirect.com/science/article/abs/pii/S017221900000096X
9. https://www.britannica.com/topic/Bureau-of-Indian-Standards
10. https://sites.nationalacademies.org/cs/groups/pgasite/documents/webpage/pga_072484.pdf
11. https://researchguides.ben.edu/general-research/source-types