on the guide card for each main entry term a list of the other main entry termswith which it stood in semantic relation: the latter included synonyms, broaderterms, narrower terms and related terms [8, § 415, 423]. The “logical key”served as the syndetic structure of the index, indicating a web of conceptualrelations otherwise unexpressed by the alphabetical structure of the index file.

Organisation may be called the science of the 27numbers simultaneous control of numbers. Organisa-tion whether small or large, is the directconsequence of numbers and the greater the numbers, the moreneed for organisation. Numbers compel us to organise, withoutsome organisation there can be no effective management, noeffective control

If this fits your style and you don’t get any value out of having cards with locators like 3a4b/65m1, then don’t do that (for you) useless make-work. Make sure your system is working for you and you’re not working for your system.

Warner's view is related to what might be termed a hermeneutical approach to searching (cf. Boell & Cecez-Kecmanovic, 2010) as opposed to a positivist approach. The positivist view implies that searching can be done in a formal way (algorithmic) that retrieves relevant knowledge without bias in the search (and this is the assumption behind evidence-based practice). The hermeneutic approach is based on the assumption that there is a constant reinterpretation of the relevant literature, implying the need for great flexibility in search criteria and a great level of iteration in search processes—and, most important, an understanding of what is going on during the search.

A fourth level of KO in Boolean systems is generated by the searcher

A third level of KO in classical databases consists of the information retrieval thesaurus,19 ontologies, and other kinds of controlled vocabulary constructed by information specialists.

Another level of KO is the bibliographical record and its organization into fields (and the corresponding organization of data in linear and inverted files). Such records vary from database to database and from host to host.

The selection of material to the bibliography constitutes the first and most basic level of KO. Because the meaning of terms is implicitly understood in this disciplinary context and to the extent that classification and indexing is based on the principle of “literary warrant,” this selection influences the developments of thesauri and ontologies, which may thus be understood as a higher level of KO.

Given the Boolean model, the goal for KO can be understood as improving bibliographical records in ways which improve searchers' selection power.

In the Boolean model, a great range of strategies are available to increase “recall” and “precision” (sometimes termed “recall devices” and “precision devices”). To utilize such devices in optimal ways, the user has to know about the databases, search facilities, documents, genres, languages, paradigms, and so on, in which he or she is searching. This should be part of what is often termed information literacy.

The problem is not that best-match systems are being developed, but that an ideological tendency to make things “user friendly” (and the market bigger) tends to hurt the development of systems aimed at increasing the selection power of users and search experts.

But much of the popularity of contemporary search engines may also be attributed to the easy pickings afforded by the first generation of Internet full-text based systems (owing to the cheap cost of digital storage capacity after 1990): no doubt it is good to have all text on the web indexed and made searchable—and often with free access. However, when the easy pickings have been utilized, more complex strategies (and more humanistic approaches) may be needed to make further progress.

Again, though, if maximum recall is required, it is impossible in ranked retrieval to know what is omitted by new queries, whereas Boolean queries allow the user to control and modify the search until a satisfactory result has been achieved and they therefore also seem better suited to iterative searches.

For a researcher conducting human studies, writing a dissertation, finding information pertinent to patient care, or conducting an in-depth literature review, Google Scholar does not appear to be a replacement for PubMed, though it may serve effectively as an adjunct resource to complement databases with more fully developed searching features.

To understand the possibilities of Boolean search when used in its most advanced ways, it is necessary to know about bibliographical records in online databases,

As previously mentioned, the medical domain is an exception to the general trend that the study of the optimization of document searching strategies has suffered in information science.