Bonn and Smith’s Categorisation of Scientific and Technical Literature

Every student of library and information science quickly learns one truth: not all documents carry information in the same way. A patent, an encyclopedia, and a directory all sit on the shelf, yet each plays a very different role in the flow of knowledge. To make sense of this, scholars have built schemes that sort documents into neat groups. One of the most discussed schemes for scientific and technical writing comes from George S. Bonn and Linda C. Smith. Their model divides literature into primary, secondary, and tertiary layers, and it offers a few distinctive choices that set it apart from rival schemes. This post walks through their categorisation in detail and compares it with the more widely used models of Grogan and Subramanyam.

Who were Bonn and Smith, and what did they classify? 🔗

The scheme is often credited to two names, but it began with one. George S. Bonn first proposed a way of grouping scientific and technical sources, and Linda C. Smith later revised and extended that work. For this reason you will see the model written as “Bonn and Smith” in most textbooks. A key point to remember is the scope. Their categorisation deals only with scientific and technical literature, not with documents from the humanities or social sciences. It also focuses mostly on published sources, leaving aside official publications and the large body of unpublished material such as laboratory notebooks and internal memoranda.

Like several other thinkers in the field, Bonn and Smith based their grouping on how information changes form as it moves from its first appearance to later, reorganised versions. A discovery is reported once for the first time, then it is summarised and indexed, and finally it is pointed to by guides and directories. Each stage produces a different kind of source, and that journey is the backbone of their three-level scheme.

Primary sources in the Bonn and Smith scheme 🔗

Primary sources are the records of original research. They carry new information that is being reported for the first time, before anyone has condensed, reorganised, or commented on it. In the Bonn and Smith model, the primary group is built around four main types of material.

Records of original research 🔗

This is the heart of the primary category. Periodicals, especially research journals, make up the bulk of primary scientific literature because they are where scientists first announce findings to the wider community. Original research published as articles in peer-reviewed journals presents fresh data, new discoveries, and the immediate results of laboratory or field work. Research monographs also belong here, since a research monograph is essentially a long research article or a short book devoted to a single theme. It is worth noting that only research monographs qualify as primary; monographs that merely gather and restate earlier findings do not.

Patents 🔗

A patent is a legal document that describes a new invention or process in technical detail. Because it sets down original technical information that may exist nowhere else, it counts as a primary source. Patent information often provides research detail on new products or processes that is rarely republished in journal articles, which makes patents especially valuable to engineers and industrial researchers.

Standards and manufacturers’ literature 🔗

Standards specify agreed rules, measurements, and quality benchmarks for products and procedures. Manufacturers’ literature, also called trade literature, includes catalogues, product specifications, and technical pamphlets issued by companies. Both record original, first-hand information about specific products and methods, so Bonn and Smith treat them as primary. The inclusion of trade literature is a practical touch, since this material is heavily used in applied science and industry even though it is sometimes overlooked in academic schemes.

Secondary sources in the Bonn and Smith scheme 🔗

Secondary sources are organised works that derive from or refer to primary literature. They digest, summarise, and reorganise original findings so that users can locate and absorb knowledge more easily. Bonn and Smith give this layer a wide membership.

Reference and review works 🔗

This group includes handbooks, encyclopedias, treatises, dictionaries, and review articles. Each one repackages material that first appeared in primary sources. An encyclopedia entry, for example, pulls together established facts and presents them in a convenient form rather than reporting new experiments. Reviews summarise and synthesise a body of primary research, which is why secondary sources are described as documents derived from the study and analysis of primary information.

Bibliographies and indexing services 🔗

Bibliographies, abstracting serials, and indexing journals help users discover where original information lives. A bibliography of research articles points readers toward the primary literature, and because it organises and lists those works, it is classed as secondary. Abstracting and indexing serials work the same way by condensing and signposting research output.

Machine-readable databases and translations 🔗

One feature that gives the Bonn and Smith model lasting relevance is its explicit place for machine-readable bibliographic databases and databanks. Long before today’s online catalogues and citation databases, the scheme recognised that electronic compilations of bibliographic data belong among secondary sources. Equally distinctive is its treatment of translations. A translated work makes the content of a primary or secondary source available in another language, and Bonn and Smith list translations as information sources in their own right, a detail that many rival schemes simply leave out.

Tertiary sources in the Bonn and Smith scheme 🔗

Tertiary sources sit at the top of the chain. They generally carry no subject knowledge of their own. Instead, they tell the user where to find primary and secondary material. In other words, they provide information about information.

Directories and guides to the literature 🔗

Directories of persons, organisations, or products help researchers locate the people and bodies active in a field. Guides to the literature explain what sources exist on a subject and how to use them. Both are pointing tools rather than content carriers, so Bonn and Smith group them as tertiary. This matches the broader understanding that tertiary sources present condensed material with references back to the primary and secondary literature and rarely contain original material themselves.

The curious placement of textbooks 🔗

Here lies the most debated choice in the whole scheme. Bonn and Smith place textbooks under tertiary sources. Their reasoning is that a typical textbook does not report fresh discoveries; it gathers established facts already reported in primary sources and presents them in an organised teaching form. From this angle a textbook acts more like a guide to existing knowledge than a record of new knowledge. This placement is unusual and is a major reason the model stands out, because most other thinkers disagree about where textbooks should sit.

Comparison with other models 🔗

The Bonn and Smith scheme becomes far easier to appreciate when set beside the work of Grogan and Subramanyam, since all three sort documents by how information changes form across the primary, secondary, and tertiary stages. The differences lie in the details, and those details reveal that the criteria for categorisation are not yet fixed firmly.

Grogan’s widely accepted model 🔗

Denis Grogan’s three-fold classification is often called the most accepted and universally prevalent scheme. Grogan distinguished three document types: primary, which records new information for the first time; secondary, which presents that same information in a reorganised form; and tertiary, which carries no subject information but guides users to the other two. Grogan’s tertiary list includes bibliographies of bibliographies, yearbooks, directories, guides to literature, and lists of research in progress. Crucially, Grogan placed textbooks among secondary sources, treating them as digests of primary research rather than mere pointers.

Subramanyam and the textbook puzzle 🔗

Subramanyam also proposed a three-level grouping and, like Grogan, treated textbooks as secondary sources. Set the schemes side by side and the disagreement is striking. A single document type, the textbook, is sorted three different ways: Giljarevskij placed it under primary, Grogan and Subramanyam under secondary, and Bonn and Smith under tertiary. The same lack of agreement appears with monographs, manuals, yearbooks, bibliographies, and directories. This shows that the line between primary, secondary, and tertiary is not rigid, and naming has not always been precise.

What makes Bonn and Smith distinct 🔗

Compared with these rivals, the Bonn and Smith model carries a few signatures. It is built specifically for scientific and technical literature rather than all writing. It folds trade literature and standards firmly into the primary layer, reflecting an applied-science outlook. It is one of the few schemes to give translations and machine-readable databases an explicit home in the secondary layer. And it takes the boldest stand on textbooks by pushing them all the way to the tertiary level. Each of these choices reflects a consistent logic: a source belongs to primary only if it carries genuinely original technical information, and anything that mainly repackages or points to such information drops down a level.

Why these categories still matter 🔗

Sorting sources is not an academic game. It shapes how libraries arrange collections, how reference staff answer queries, and how researchers plan a literature search. A scholar starting on a fresh topic usually moves from tertiary tools that map the field, to secondary works that summarise it, and finally to primary sources that supply original evidence. Understanding which scheme places a document where helps a professional decide what to consult first and what to trust as original. The disagreements between Bonn and Smith, Grogan, and Subramanyam are therefore useful rather than annoying, because they push us to ask what a document actually does rather than what label it wears.

What do you think? Do you agree with Bonn and Smith that a textbook is really a tertiary source, or does it carry enough organised knowledge to be secondary? And if you were building a categorisation for today’s digital sources, where would you place preprint servers and open citation databases?

References

1. https://www.sciencedirect.com/topics/social-sciences/tertiary-source
2. https://library.onu.edu/c.php?g=357773&p=2720217
3. https://libguides.umn.edu/c.php?g=986651
4. https://ebooks.inflibnet.ac.in/lisp4/chapter/types-of-information-sources-documentary-primary-secondary-and-tertiary/
5. https://libguides.ccu.edu/c.php?g=781057&p=5599175