By Marcia J. Bates
School of Librarianship, University of Washington, Seattle, WA 98195
Journal of the American Society for Information Science, v. 30, July 1979, p. 205-214
Received September 12, 1978; revised February 12, 1979. © 1979 by John Wiley & Sons, Inc.
As part of the study of human information search strategy, the concept of the search tactic, or move made to further a search, is introduced. Twenty-nine tactics are named, defined, and discussed in four categories: monitoring, file structure, search formulation, and term. Implications of the search tactics for research in search strategy are considered. The search tactics are intended to be practically useful in information searching. This approach to searching is designed to be general, yet nontrivial; it is applicable to both bibliographic and reference searches and in both manual and on-line systems.
For all the developments in automated and semiautomated information retrieval, nothing yet matches the ability of experienced human searchers—whether known as “information specialists” or “reference librarians”—who move skillfully among an enormous range of resources, both manual and on-line, to develop bibliographies or answer questions. We know discouragingly little about just what those skills are and how they develop; we cannot yet define what it is that an experienced searcher knows that a beginner does not.
In this article, the concept of the information search tactic is introduced
and various particular tactics are named and described. These tactics are designed
to be of assistance to the searcher while in the process of searching, and secondarily
in teaching fledgling searchers their work. They may also suggest various lines
of research on search strategy, including, ultimately, efforts to describe and
distinguish the skills of the experienced searcher.
The plan of this article is first to give a brief literature review of human information search strategy; second, to discuss the concept of the tactic; third, describe the 29 tactics to be used in information searching; and finally, show some implications of tactics for research in search strategy.
The orientation of this article is toward professional, as opposed to lay, information searching. The tactics, intended to be practically useful in information searching, are applicable to both bibliographic and references searches* in both manual and on-line systems, and to all types of questions and subject fields.
Much of the searching done by the professional information specialist requires
very little in the way of strategy. Simpler, so-called “ready reference”
questions are usually answered by mentally retrieving in a second or two the
name of a suitable source, going to the source, and getting the answer. In such
cases, the tactics proposed below are seldom needed. The tactics are primarily
designed to help in more complex searches—those involving many stages,
or those that resist the automatic mental retrieval of satisfactory answering
A few of the tactics described are well known and discussed—though
often unnamed—in the library/information science literature; others may
be used but are not consciously articulated, let alone named; and still
others may be unknown in every respect to most searchers, instructors, or researchers
in the field. Even with those tactics that a searcher already uses and recognizes,
there may be benefit to be gained by reading about them nonetheless. It is a
basic premise of this article that to articulate and name a tactic makes it
more available in the searcher's mind; it makes it more easily and readily applied.
A major orientation of the article is to focus on and use the strengths and
flexibility of human thinking processes. It is suggested that search theory
and practice may be advanced through a greater attention to the specifically
human, psychological processes involved in searching, as distinct from the logical,
or formal, properties of the process. In addition, we turn from a focus
on the machinery, the information technology, to the brain that is running it.
Information Search Strategy Literature
There is relatively little literature dealing with information search strategy—especially by that name. We must look several places to find all that might be relevant to the subject. The phrase “search strategy” is probably found most often in the literature of computer on-line searching. Stevens  reviews a number of these articles (also see issues of Online Review, founded in 1977). Typically, in these articles search strategy is viewed as specific to on-line searching. The on-line search is not seen as a part of a broader search process. To put it another way, the unifying factor is the computer on-line system, not the human being running the terminal.
Some literature deals with whether computers can assist the
searcher or be used for any of the steps normally performed by humans [see,
e.g., refs. 2-5]. Interesting insights about
human searching are sometimes provided by these human-machine comparisons, and
receive later mention in this article where relevant.
While the phrase “search strategy” is less commonly used in traditional
librarianship, the field has had a longstanding interest in the “reference
process,” which sometimes includes searching procedures. Though reference
work has been recognized as a library function since before the turn of the
century, traditional texts in reference work said little or nothing about searching
[6-8]. Hutchins  was exceptional in her attention to how to answer questions.
As for theory of search strategy, there has been essentially none until quite
recently; in fact, up to the 1970s, there was ongoing debate about whether
there was theory of any kind in ref. 10. Since Wynar’s article noting
the lack of theory in the field, a number of articles have appeared positing
reference theories [11-15], but these are fairly brief and general and
say little about searching.
However, some articles have appeared that deal more specifically with information
searching. Neill  applies the psychologist Guilford's "Structure of
Intellect" model to the reference process, and Benson and Maloney ,
in their analysis of the search process, focus on building a “bibliographic
bridge” between system and query.
A number of attempts have been made to analyze the reference process or, more
specifically, the search process, in flow chart form. Katz , in a modern
reference text that deals much more extensively with searching than earlier
texts, reviews no less than eight such models. (Incidentally, Katz's chapters
on searching in the recent editions of his text [18, 19] constitute excellent
reviews of this literature.) These models vary in specificity. Stych's model
[18, pp. 134-135], for example, goes into great detail, down to the type of
reference book and even specific sources, to try for answers at various decision
points. On the other hand, the Rees and Saracevic model [18, p. 137] gives “selection
of search strategy” as a single step in a ten-step model of the reference
Nothing was found in this literature on search tactics, or dealing with search
strategy from the standpoint of tactics. Josel's article, “Ten Reference
Commandments” , with hints for reference work, comes closest.
Finally, one other body of literature may be expected to be of use: that on
the psychology of problem solving. Nothing was found in that literature
directly related to information searching, but Adams [21, p. 66] lists
a number of verbs as general problem-solving “strategies,” an approach
which resembles that used here for tactics. Where appropriate, other references
are made below to the problem-solving literature.
The Concept of the Search Tactic
In order to elucidate the role of the tactic in human information
searching, it is first useful to distinguish various types of models that may
be developed in studying this area. At least four different sorts of models
of search strategy can be distinguished, models for idealizing searching,
representing searching, teaching searching, and facilitating
searching.** An ideal model specifies ideal search patterns
on the basis of mathematical, system analytic, or other formal criteria of optimality.
Representation models exist for the scientific purpose of describing, and ultimately
predicting and explaining, the human behavior known as information searching;
these models represent what people actually do or think in searching. A good
teaching model is one that makes it easy for people to learn to search. A model
for facilitating searching is one that searchers can use while in the process
of searching, one that helps them search more efficiently or effectively.
These different functions impose different requirements for what constitutes
good models in each case. Conceivably, a very good single model could be found
that would be optimal for all these purposes in one. But it is more likely that
different models will have to be found for each function. For example,
system analytic or mathematical theories of optimal searches, while good descriptions
of ideal searching, may be predicted to be of little interest for the practice
of searching to the typical information specialist, whose mathematical background
Good models that join the teaching and practice functions are more likely
to be found than ones that join other pairs of these functions. But even here
differences can be found. The best way to learn something when first encountering
it may be different from the best way to think about that same thing once familiar
with the ideas.
The model presented here is intended primarily as a facilitation model and secondarily
as a teaching model. It is assumed at this point that the model will function
well in both capacities; later testing will determine whether it is, in fact,
useful in neither, one, or both of these capacities. Students of search behavior
who are attempting to develop representation models may find this an interesting
starting place as well. The concept of the tactic, as well as particular tactics,
may be found to be useful and appropriate for describing the behavior of
skilled searchers. (Different results may be found for those who have and for
those who have not been exposed to the concepts in this article.)
“Strategy” and “tactics” are terms best known for their
military uses. Webster's New Collegiate Dictionary  defines them as follows:
Strategy: The science and art of employing the armed strength of a belligerent to secure the objects of a war, esp. the large-scale planning and directing of operations in adjustment to combat area, possible enemy action, political alignments, etc.; also, an instance of it.
Tactics: 1. (usually construed as sing.) The science and art of disposing and maneuvering troops or ships in action or in the presence of the enemy. 2. (usually construed as pl.) Hence, any method of procedure; esp., adroit devices for accomplishing an end.
Strategy deals with overall planning; tactics deals with short-term goals and
Let us now adapt these terms for use in information searching. The definitions
below are general and simple, and may be refined in later theoretical development.
Search tactic: A move made to further a search.
Search strategy (in searching); A plan for the whole search.
Search strategy (as an area of study): The study of the theory, principles, and practice of making and using search strategies and tactics.
Search behavior: What people do and/or, as far as can be determined, what they think when they search.
Every move a person makes toward the goal of finding desired information is
seen as a tactic. Hence, there can be good, or effective, tactics and bad ones.
The purpose of this model is to suggest tactics that are thought likely to improve
the effectiveness or efficiency of a search. The word “likely” is
important, however. These tactics are heuristic; they may help, but not necessarily.
Furthermore, a tactic may be good in one situation and not in another. Further
development of the model may make it possible to state the circumstances under
which certain tactics are most likely to be useful. (See also the section “Implications of Search Tactics for Research in Search Strategy.”)
The tactics described here are concerned with the search proper: threading one's
way through the file structure of the information facility to find desired sources,
fitting the search as conceptualized to the vocabulary of the system/ resources,
and monitoring the search, that is, keeping it on track. Another aspect of searching,
getting ideas to overcome a stymied search, will be dealt within a future
article, "Idea Tactics." Other areas of the overall search process
which may lend themselves to the development of search tactics are the reference
interview, the initial analysis of question and search design, consultation
with the patron during and after the search (which may be considered a part
of the reference interview, broadly conceived), and determination of the
relevance of information found.
Four types of tactics are distinguished here:
(1) Monitoring tactics are tactics to keep the search on track and efficient.
(2) File structure tactics are techniques for threading one's way through the file structure of the information facility to desired file, source, or information within source.
(3) Search formulation tactics are tactics to aid in the process of designing or redesigning the search formulation. (These tactics are not restricted to computer search formulations.)
(4) Term tactics are tactics to aid in the selection and revision of specific terms within the search formulation.
A note on “file structure,” since the phrase is used here in a somewhat
unconventional way—All the information in a typical information facility
can be seen as organized into a structure. Typically, there are a number of
different types of file, each ordered according to different principles, and
these files are interrelated through common access in a central file such
as a catalog. (The concept of “file” as used here includes not only
those things conventionally called by that name, but also any ordered set of
information individuals. The “book” is a typical such individual;
thus, for example, the ordered set of books contained in the A/Z call number
range of a library's main stack collection is also a file.) The closest traditional
librarianship comes to a name for this structure of files is “bibliographic
control,” a phrase used in so many different ways as to be almost meaningless.
In information science, “file organization” is generally restricted
to computer usage. So, “file structure” is used here to refer to
the overall pattern, or structure, of organization of information in an information
This concept is not to be confused with particular classification or indexing
systems. The point here is that there is a more general way of viewing information
organization than through particular systems. All indexing and classification
systems provide a structure; the interest here is in the fact of the structure,
not in the specific character of that structure. It is seen that the tactics,
though they deal with threading one's way through the file structure, do so
independently of particular systems of information organization.
With regard to the whole set of tactics, some overlapping will be noticed, as
well as some hierarchical relationships. VARY, for example, will be seen to
be the general case, against several specific forms of variation that follow
it in the term tactics. These relationships have been retained for two reasons.
First, if we view the identification and understanding of tactics as our problem
to solve as researchers, then the following point on research strategy needs
to be made: While our goal over the long term may be a parsimonious few, highly
effective tactics, our goal in the short term should be to uncover as many as
we can, as being of potential assistance. Then we can test the tactics
and select the good ones. If we go for closure too soon, i.e., seek that parsimonious
few prematurely, then we may miss some valuable tactics.
Second, it may prove that a larger set of tactics, including even overlapping
ones, makes a better facilitation model anyway, for psychological reasons. I
suggest that this is likely the case. The use of these tactics is a form of
creative problem solving. In such cases the mind may not work in logical, regular
patterns. It may come at a problem from many different levels and angles. It
may use one tactic on a particular type of problem one time and a different
one on the same sort of problem the next time. In other words, we may find that
the requirements of a good facilitation model of searching include some redundancy,
and that an across-the-board application of parsimony (economy of logical formulation
and expression) is more appropriate to ideal and representation models. (Even
if this is so, it nonetheless does not preclude the possibility that parsimony
is desirable in some respects in a facilitation model. For example, while using
a large, nonparsimonious set of tactics, it may still be desirable to have definitions of the tactics that are as concise as possible.)
In Table I are listed and defined all
of the (presumably useful) tactics for the search proper that I have been able
to discover to date. The 29 tactics are adapted from my own experience and thinking,
from the literature, and from the comments of colleagues and students.
Since tactics are moves, they are presented in verb forms, one may think of them either as commands (CUT!) or as infinitives (TO CUT). Names of tactics have been selected to be brief and striking.
Discussion of Tactics
Definitions of tactics are given below in the context of a broader discussion
and explanation. Where no discussion is deemed necessary, definitions are stated
MONITORING TACTICS: Tactics to keep the search on track and efficient.
MI. CHECK. To review the original request and compare it to the current search topic to see that it is the same.
M2. WEIGH. To make a cost-benefit assessment, at one or more points of the search,
of current or anticipated actions. Among other things, the searcher might consider
whether any other approach would be more productive for the effort.
M3. PATTERN. Frequent experience with a type of question may lead to an habitual
pattern of search [see also 19, p. 87ff] . If, for example, a common request
in an academic library is for addresses of researchers, then the librarian may
soon develop a sequence of sources to search, arranged by their likely productivity.
To PATTERN is to make oneself aware of a search pattern, examine it, and redesign
it if not maximally efficient or if out of date.
M4. CORRECT. To watch for and correct spelling and factual errors in one's search
topic. These may exist in the topic as presented originally by the user (cf.
Josel's first “reference commandment” [20, p. 146]), or may slip
into the searcher's thinking in translating a verbal request, or in remembering
(without having in hand) a written request. In observing bibliographic searching
done by several librarians, Carlson noted that the searchers would allow
inaccuracies, particularly spelling errors, to slip into their search formulation.
One librarian, for example, had a request on “neuroglia,” and
searched instead on “neuralgia,” a very different concept. He noted
several cases where a difficult technical term was not written down and the
librarians “would search for the remembered spelling, usually not find
it, and then stop the search for that term” [5, p. 29].
A clue to errors in the request as stated may be provided by suspicious
coincidences. Josel's fourth “reference commandment” is “Coincidence
is no coincidence.” As he says: “When a patron wants to have a biography
of Saint Edmund Hall, born 1226, and you find the same name listed as a college
of Oxford University, and 1226 as its date of construction, do not doubt the
patron needs further talking to” [20, p. 146].
M5. RECORD. To keep track of trails one has followed and of desirable trails
not followed up or not completed. In complex searches it is sometimes necessary
to return to the source of information or citations recorded earlier in the
search. For example, after recording a number of citations from a periodical
index, the searcher may then attempt to retrieve the articles cited and find
a blind lead. The citation needs to be checked again in the original source.
But unless the source, volume date, and subject term searched under were recorded,
the searcher may have to go through the entries under a dozen terms or in several
volumes to locate the desired citation. Similarly, if productive on-line and
manual bibliographic search formulations are retained, later repeat effort may
As for trails not followed up or not completed, Carlson noted the following in his observations of librarians:
They are not consistent in recording what they find or what they intend to check later. In many cases, the human will find cross-references and state that they will check these cross-references later. Unless they make some written now, they never seem to check them. Each librarian studied, at some time during the search, noticed some discrepancy either in an item being scanned, or in an item recorded as acceptable, and made the verbal comment that he would check this later. Once again they almost never made a written note about this and when they did not write a note, they never did check the item. The discrepancies which arose during the search were thus not clarified. [5, pp. 29-30]
The searcher may choose not to follow up some side trail or problem, but it appears that such choices are often made by default, rather than deliberately.
FILE STRUCTURE TACTICS: Techniques for threading one's way through the
file structure of the information facility to the desired file, source, or information
Fl. BIBBLE. One way to cope with the file structure is to find a way to do without
it altogether. The only neologism among the set of tactic names, BIBBLE is based
on the abbreviation “bibl.” for “bibliography.” To BIBBLE
is to look for a bibliography already prepared, before launching oneself into
the effort of preparing one. More generally, to BIBBLE is to check to see if
the search work one plans has already been done in a usable form by someone
F2. SELECT. To break complex search queries down into subproblems and work on
one problem at a time. This tactic is a well-established and productive technique
in general problem solving. As each subproblem is solved, the parts can then
be knit into a solution to the whole, larger problem.
F3. SURVEY. To review at each decision point of the search the available options
before selecting. In Carlson's description of human searching behavior, he noted
the following problem: “There is almost no look-ahead in the human search
procedures. All of the librarians studied exhibited to some extent this
lack of look-ahead. They would often scan each entry as they came to it and
then encounter a heading which would alter the search procedure.” He concludes:
“Here the lesson is very clear: humans should scan over a reference document
before making any detailed searches through it” [5, p. 35]. Psychologically,
this is a problem of “going for closure” too soon, that is, settling
on a source or approach prematurely. In employing SURVEY, one resists that temptation
and presumably achieves a more effective search.
For example, in a bibliographic search, instead of selecting the first
index that comes to mind, one thinks of all the major indexes in the subject
and then selects the one best suited to the particular query. Then, instead
of moving immediately to a subject entry term within the index, one first
scans through the thesaurus to find the best term or terms for the subject.
F4. CUT. When selecting among several ways to search a given
query, to CUT is to choose the option that cuts out, eliminates, the largest
part of the search domain at once. In my opinion, this tactic is of fundamental
significance in our field, and is relatively little known or discussed. Here
are some examples: When looking up a book written by Smith and Brzustowicz,
the search will be much briefer if one looks under Brzustowicz (assuming the
file has entries under co-authors). In most files, there will be far fewer entries
to scan under the latter name. Thus, in choosing to search under the latter
name, with its few entries, one has cut out a larger part of the search domain
than would be the case when searching under Smith, and has shortened the search
Similarly, in a subject search, other things being equal, one should look up
the most specific elements of the topic first. For example, in using a KWIC
(rotated title term) index, the searcher will find desired material on
the topic “Research in Retinopathy” much faster by looking under
the more specific term “retinopathy,” because there will be fewer
The concept of CUT has received the most explicit use in information science
in manual coordinate indexing searching. If one pulls three subject-term cards
for an ANDed search on terms A, B, and C, then makes comparisons among
term cards to find the documents indexed under all three terms, the smart tactic
is to start with the card with the fewest document numbers posted on it [cf.
23, p. 232]. Since all acceptable documents must have all three terms assigned
to them, the card with the fewest documents posted exercises the most control
and eliminates the largest part of the search domain.
F5. STRETCH. Naturally enough, one tends to think about information resources
in terms of the uses for which they are intended. However, almost all reference
sources can be used productively for some other purpose than intended.
The internal organization of a file or reference book is designed around certain
uses. Thus, access via certain record elements is provided, and access
via other elements is not. But even though formal access is not provided,
that other information is there in the source nonetheless. Introductions,
which are outside the formal internal file organization of an information source,
may also be informative in unexpected ways.
In general, it may be assumed that the most efficient searching involves using
sources for their intended purposes. But when such approaches fail, answers
may still be found by putting in the harder work to ferret out information incidentally
provided. Thus, to STRETCH is to use a source for other than its intended purposes.
However, it should be kept in mind that to STRETCH effectively the searcher
must first think differently, he/she must think about all the information that
is in a source, not just about the ordinary uses of it.
For example, after searching unsuccessfully through many directories for the
address of an engineer, the searcher may recall that patents contain the name
of the inventor and also the business affiliation, since the patent is
usually owned by the company she/he works for. If the engineer has patented
anything, then the address should be available in the nearest patent file.
F6. SCAFFOLD. Hodnett discusses the use of what he calls “auxiliaries”
[24, p. 94ff.] which are aids in problem solving which may or may not themselves
be a part of the solution, but which make the solution possible. The technique
of using auxiliaries is often employed in mathematics, where a seemingly irrelevant
theorem is introduced, a theorem with little intrinsic interest, but one that
enables the main theorem to be proved.
The use of scaffolding in construction is another such example. When the building
is finished, the scaffolding is torn down, but the building could not have been
built without it. In information searching, it is sometimes the case that the
shortest route through the file structure is a dead end. In that case one may
build a roundabout path to the answer by going through files or sources that
themselves may seem to have nothing to do with the question. One may acquire
an additional piece of information that in no way contributes directly to the
answer but which makes it possible to search for the answer in some other source.
Thus, to SCAFFOLD is to design an auxiliary, indirect route through the information
files and resources to reach the desired information. For example, after unsuccessfully
seeking information on an obscure poet, the searcher may find out who the poet's
contemporaries were and research them in hopes of finding mention of the poet.
F7. CLEAVE. To employ binary searching in locating an item in an ordered file.
(For those unfamiliar with this principle: In binary searching one first looks
at a record in the middle of an ordered, e.g., alphabetized, file. One then
determines the half of the file in which the desired record must lie. Then the
middle record in that half of the file is looked at, and the quarter of the
file in which the record must lie is determined. Then one looks at the middle
record in the quarter section of the file, and so on until the desired record
is discovered. In each case, the file is split in two, hence the term “binary” [see also ref. 25].)
Formally, binary searching is a more efficient approach than serial or random
searching. Yet a rigid adherence to this principle would probably be wasteful,
since human beings have additional contextual knowledge about many files. For
example, a searcher looking for the telephone number of the Ajax Corporation
will not start the search in the middle of the white pages. On the other hand,
a general awareness of binary searching may enable searchers to improve
efficiency, particularly when confronting large and unfamiliar files. The use
of CLEAVE, as well as means of testing its usefulness, are discussed in more
detail in ref. 26.
SEARCH FORMULATION TACTICS: Tactics to aid in the process of designing or redesigning
the search formulation.
SI. SPECIFY. To search on terms that are as specific as the information desired.
Specificity is one of the crucial concepts in systems of information access.
Almost all systems of classification and indexing require that descriptions
assigned to materials be as specific as the content of the materials and as
the indexing system itself allows. Sears and Library of Congress subject headings
use the “rule of specific entry” which requires entry of materials
under the most specific terms that still encompass the content of the item;
coordinate indexing, with its focus on “concept” indexing,
brings about highly specific description, and so on.
Thus, specificity at the time of indexing requires specificity at the time
of retrieval. An indexing system may or may not allow entry under broader terms
as well, but it will almost always require specific entry. Thus, it is probably
the case that starting with specific terms in all kinds of searches (including
both bibliographic and reference) will be the most productive approach [for
further discussion see ref. 26] .
S2. EXHAUST. To include most or all elements of the query in the initial search
formulation, or to add one or more of the query elements to an already-prepared
search formulation. Both this and the next tactic, REDUCE, are related to Lancaster's
use of "exhaustivity" [27, p. 71ff.]. In searching, the more exhaustive
a search is, the more of the elements of a complex request have been included
in the search formulation. For example, the searcher interested in the
“training of teachers of mathematics for the elementary grades”
has a four-element problem. An exhaustive search would include all four
elements in its formulation. Both EXHAUST and REDUCE deal implicitly with
the number of elements in the query that are to be ANDed together in the search
formulation. The more exhaustive the search statement, the more stringent the
requirements, and thus the fewer the documents likely to be returned on a search.
While this tactic is probably most useful for Boolean searching, it is also
meaningful for other kinds of searches. For example, in a catalog using Library
of Congress subject headings, one can decide between searching under the main
heading only or more exhaustively under the main heading plus geographical,
bibliographical form, or other nontopical subdivisions.
S3. REDUCE. To minimize the number of elements of the query in the initial search
formulation, or to subtract one or more of the query elements from an already-prepared
search formulation. REDUCE is the opposite of EXHAUST. This tactic reduces the
number of ANDed elements in the search formulation, making the search specification
less stringent, and thus increases the number of documents likely to be returned
on a search.
S4. PARALLEL. To make the search formulation broad (or broader) by including
synonyms or otherwise conceptually parallel terms. PARALLEL and PINPOINT
deal implicitly with elements in a query that are to be ORed together. Though
these tactics are most readily applied in on-line Boolean searching, they may
also be used in manual searching. For example, in the process of manually compiling
a bibliography, one may look over catalog subject headings and terms in
periodical indexes and expand the number of similar terms searched under (PARALLEL),
either at the beginning of the search or after getting some experience with
the type and quantity of materials under each term.
S5. PINPOINT. To make the search formulation precise by minimizing (or reducing)
the number of parallel terms, retaining the more perfectly descriptive terms.
PINPOINT is the opposite of PARALLEL.
S6. BLOCK. To reject, in the search formulation, items containing or indexed
by certain term(s), even if it means losing some document sections of relevance.
This tactic deals implicitly with the Boolean AND NOT. The term NOT was not
used, however, because the concept extends beyond the usual applications of
Boolean searching. For example, in doing a manual literature search, one may
choose to reject all items containing a certain word in the title. BLOCK was
selected as the name of this tactic to draw attention to the tricky side of
NOT—to the fact that in eliminating a document that contains an undesired
term, one may also block out desirable material that happens to be found in
the same document.
TERM TACTICS: Tactics to aid in the selection and revision of specific
terms within the search formulation.
Tl. SUPER. To move upward hierarchically to a broader (superordinate) term.
Searchers may be assisted by pointers in a thesaurus or may have to rely on
their own knowledge to devise the term.
T2. SUB. To move downward hierarchically to a more specific (subordinate) term.
T3. RELATE. To move sideways hierarchically to a coordinate term.
T4. NEIGHBOR. To seek additional search terms by looking at neighboring terms,
whether proximate alphabetically, by subject similarity, or otherwise.
Coates pointed out many years ago that all manual (and we should add today,
most automated) information organization systems do two fundamental things:
locate and collocate [28, Chap. 3]. The primary function of such systems is,
of course, to enable the searcher to find, or locate, desired materials. However,
such systems also necessarily collocate entries. In any ordered file everything
must be next to something else. Many of the historical arguments over the relative
merits of classification and indexing systems were as much about collocation
as location. Consider, for example, the old debate over whether to have classified
or alphabetico-specific subject catalog access. A classified catalog collocates
entries by their conceptual relationship; an alphabetico-specific catalog collocates
entries only by their alphabetical order. These two approaches have different
strengths and weaknesses and different consequences for search strategy
[28, Chap. 3].
To use this tactic is to expand the search by examining the proximate entries,
whatever they are. In on-line searching, one examines whatever proximate
entries are made available by the on-line program one is using. (NEIGHBOR happens
to be the current term for the appropriate command in the SDC ORBIT® search language.)
Incidentally, the use of NEIGHBOR may be extended beyond term selection to resource
selection as well. Since classification systems collocate books, it is easy
to extend a search by examining related sources collocated on the shelves of
the reference stacks.
T5. TRACE. To examine information already found in the search in order to find
additional terms to be used in furthering the search. Two of the most common
ways of doing this are to scan descriptor term lists in citations retrieved
in on-line searching, and to scan on a catalog card the list of other headings
that have been given to the document in question. These other headings
on the catalog card are called the "tracings," hence the name for
this tactic (cf. Josel's seventh “reference commandment” [20, p.
T6. VARY. To alter or substitute one's search terms in any of several ways.
See remaining term tactics for some specific variations.
T7. FIX. To try alternative affixes, whether prefixes, suffixes, or infixes.
Several may be done at once through truncation routines.
T8. REARRANGE. In any system where terms may contain more than one word, word
order may make a difference in retrieval success. To REARRANGE is to reverse
or rearrange the words in search terms in any or all reasonable orders.
T9. CONTRARY. To search for the term logically opposite from that describing
the desired information. For example, one may want information on “cooperation”
and, after an unsuccessful search, change the term to “competition.”
T10. RESPELL. To search under a different spelling. CORRECT dealt with maintaining
correct spelling, among other things. But with RESPELL the concern is not with
correctness, but with effectiveness. Particularly in current on-line search
systems, there are a great many spelling variations that show up in the
citations. One must expand the spelling variations to insure good recall. RESPELL
is occasionally needed in manual systems too, where, for example, one needs
to change from U.S. to British spelling to search successfully in a source.
T11. RESPACE. Spacing, particularly in hyphenated words, or words that appear
with various spacings, can be critical in search success. To RESPACE is to try
spacing variants. While spacing problems are most glaring in some automated
search files, such problems can also be serious with manual files. The two fundamental
variants in filing rules—word-by-word filing and letter-by-letter filing—differ
on how the blank space is to be treated in filing [29; 30, p. 339]. Both of these rules are in wide use. The searcher who is thinking in
terms of one filing rule and enters a source that uses the other may miss the
Implications of Search Tactics for Research in Search Strategy
As experience is gained with these tactics, leads for the development of ideas
and research in other areas of human information search strategy should emerge.
Some possible directions that have already come to mind follow.
(1) Various tactics form clusters as responses to situations where a search
produces too many or too few documents. For example, where too few documents
are produced, the searcher might try SUPER, RELATE, REDUCE, PARALLEL, NEIGHBOR,
TRACE, and VARY, among others. Too many documents, on the other hand, might
lead to the use of SUB, EXHAUST, PINPOINT, and BLOCK.
A few steps may be taken in moving from a facilitation model of tactics to a
facilitation model of strategy (i.e., to a model that suggests helpful search
strategies or techniques for developing strategies) by distinguishing typical
stages of searches and then looking for useful patterns in tactics use at those
stages. If the searcher is aware that a small cluster of tactics is most likely
to be useful at a given stage, then she/he can concentrate on just those few
at that stage.
(2) It was stated earlier that the tactics presented in this article are restricted
to those dealing with the search proper: monitoring the search, threading through
the file structure, and fitting search query to system/resource vocabulary.
With experience, other tactics in the aforementioned categories should emerge.
For example, in a system as complex as an information facility, there are
surely more useful file structure tactics than have been noted here. Tactics
can also be developed for the other elements of the reference process that have
been left out here. (As noted earlier, I will present “idea tactics,”
ways of getting ideas to help with stymied searches, in a future article.) Tactics
can also be developed for moves in the reference interview. The complexity
of the interview process has been recognized in recent years, and a considerable
literature is developing in that area [see, e.g., ref. 31]. In many cases, the
reference interview, in effect, continues into the search process itself, as
the searcher returns with partial material to show the requester. User feedback
during the search adds another dimension of complexity to the search, and feedback-related
tactics should ultimately be included in any comprehensive view of search
Another aspect of the reference process with tactical potential is the stage
in which the search query is analyzed. It is at this point that search strategy
is developed. It might be possible to enrich or advance upon the flow-chart
models of search strategy already developed by devising specific tactics suitable
for this initial analysis phase. For example, Jahoda recommends as one step
in the reference process: “select sequence of specific titles to search”
[32, p. 155]. Thus, “SORT,” to mean, for example, sorting the sources
responsive to a query from most to least likely to be of help, might be seen
as one tactic to be used in this phase. Finally, tactics to aid in the evaluation
of relevance of retrieved materials would represent yet another element of the
After these various sets of tactics have been developed, an ultimate goal of
creating a single, comprehensive set of tactics can be envisioned. The set would
incorporate all elements of the reference process, from initial interview with
patron all the way to final determination of relevance and final negotiation
with patron. It would provide a unifying mode for viewing the reference
process and could constitute the core of a course in reference/information
WEIGH suggests a whole small subarea of investigation. WEIGH is a capsule
name for an on-the-spot cost-benefit assessment. Cost-benefit analysis in library/information
science generally involves extensive studies and mathematical models. WEIGH,
on the other hand, deals with what people can evaluate in their minds in a few
seconds. What is needed is a class of rules-of-thumb that the searcher can use
while searching. Such rules would be concerned with, among other things, how
to choose among several sequences of actions or among several sources. For the
latter, the rules might take into account likely productivity of source, likely
effort in use, and characteristics of query requirements, such as exhaustivity
desired or “importance” of query.
These rules might look simple but they would be based on sophisticated testing
to discover them in the first place. The point here is that while there is a
well-developed science of cost-benefit analysis for systems researchers to use,
there is no such science for information searchers to draw on while they are
in the process. What is needed, in short, are searching decisions rules that
minimize cognitive strain [cf. 33, p. 82ff.] Since staff costs are usually the
largest part of an information facility's budget, anything that can be done
to enable searchers to work faster should be a valuable improvement in information
facility system performance.
(4) One of the fundamental issues in search strategy is when to stop. Two example
stopping questions: How does one judge when enough information or citations
have been gathered? How does one decide to give up an unsuccessful search? At
least two of the tactics in the set proposed here suggest testable areas for
stopping. SURVEY was recom¬mended as a way of making sure one has found
a good source, or best term, for searching. Use of SURVEY can not only aid in
effectiveness, but also in efficiency. If the searcher does not use this tactic
and searches under the first term that comes to mind, time may be wasted with
that term in reading and recording (or having printed out) citations, before
the realization that there are better terms to use. Thus, SURVEY may be presumed
to aid both efficiency and effectiveness of the search. But there must
be a limit. In surveying, one could review every source in a library or every
term in a thesaurus. Such thoroughness would waste time. Usefulness of this
tactic probably follows a curve in which additional SURVEYing beyond a certain
point produces diminishing returns. Testing may demonstrate where that
WEIGH also includes some stopping questions. If, for example, one has mentally sorted relevant sources from most to least likely to produce information on the query, then when is the optimal time to stop searching in one source and move to the next one? That point may well come before one has exhausted every conceivable possibility in a given source.
After reviewing briefly the literature of human information search strategy,
four types of models of information search strategy were defined: models for
idealizing searching, representing searching, teaching searching, and facilitating
searching. The model in this article was presented as being primarily a facilitation
model and secondarily a teaching model.
The concept of the search tactic was defined, as well as four categories of
tactics for the search proper: monitoring tactics, file structure tactics, search
formulation tactics, and term tactics.
Twenty-nine tactics were named, defined, and discussed, and various implications of search tactics for research in search strategy were discussed.
* A major orientation of the article is to focus on and use the strengths and flexibility of human thinking processes. It is suggested that search theory and practice may be advanced through a greater attention to the specifically human, psychological processes involved in searching, as distinct from the logical, or formal, properties of the process. In addition, we turn from a focus on machinery, the information technology, to the brain that is running it.
**These four types of models may also be useful in conceptualizing research on human behavior in other areas of information science, e.g., classification/indexing and relevance assessment
TABLE I. Summary of information search tactics and definitions
|MONITORING TACTICS||Tactics to keep the search on track and efficient.|
|M1. CHECK||To review the original request and compare it to the current search topic to see that it is the same.|
|M2. WEIGH||To make a cost-benefit assessment, at one or more points of the search, of current or anticipated actions.|
|M3. PATTERN||To make oneself aware of a search pattern, examine it, and redesign it if not maximally efficient or if out of date|
|M4. CORRECT||To watch for and correct spelling and factual errors in one's search topic.|
|M5. RECORD||To keep track of trails one has followed and of desirable trails not followed up or not completed.|
|FILE STRUCTURE TACTICS||Techniques for threading one's way through the file structure of the information facility to desired file, source, or information within source.|
|F1. BIBBLE||To look for a bibliography already prepared, before launching oneself into the effect of preparing one; more generally, to check to see if the search work one plans has already been done in a usable form by someone else.|
|F2. SELECT||To break complex search queries down into subproblems and work on one problem at a time.|
|F3. SURVEY||To review, at each decision point of the search, the available options before selecting.|
|F4. CUT||When selecting among several ways to search a given query, to choose the option that cuts out, eliminates, the largest part of the search domain at once.|
|F5. STRETCH||To use a source for other than its intended purposes.|
|F6. SCAFFOLD||To design an auxiliary, indirect route through the information files and resources to reach the desired information.|
|F7. CLEAVE||To employ binary searching in locating an item in an ordered file.|
|SEARCH FORMULATION TACTICS||Tactics to aid in the process of designing or redesigning the search formulation.|
|S1. SPECIFY||To search on terms that are as specific as the information desired.|
|S2. EXHAUST||To include most or all elements of the query in the initial search formulation; to add one or more of the query elements to an already prepared search formulation.|
|S3. REDUCE||To minimize the number of elements of the query in the initial search formulation; to subtract one or more of the query elements from an already-prepared search formulation.|
|S4. PARALLEL||To make the search formulation broad (or broader) by including synonyms or otherwise conceptually parallel terms.|
|S5. PINPOINT||To make the search formulation precise by minimizing (or reducing) the number of parallel terms, retaining the more perfectly descriptive terms.|
|S6. BLOCK||To reject, in the search formulation, items containing or indexed by certain term(s), even if it means losing some document sections of relevance.|
|TERM TACTICS||Tactics to aid in the selection and revision of specific terms within the search formulation.|
|T1. SUPER||To move upward hierarchically to a broader (superordinate) term.|
|T2. SUB||To move downward hierarchically to a more specific (subordinate) term.|
|T3. RELATE||To move sideways hierarchically to a coordinate term.|
|T4. NEIGHBOR||To seek additional search terms by looking at neighboring terms, whether proximate alphabetically, by subject similarity, or otherwise.|
|T5. TRACE||To examine information already found in the search in order to find additional terms to be used in furthering the search.|
|T6. VARY||To alter or substitute one's search terms in any of several ways.|
|T7. FIX||To try alternate affixes, whether prefixes, suffixes, or infixes.|
|T8. REARRANGE||To reverse or rearrange the words in search terms in any or all reasonable orders.|
|T9. CONTRARY||To search for the term logically opposite from that describing the desired information.|
|T10. RESPELL||To search under a different spelling.|
|T11. RESPACE||To try spacing variants.|
This work was supported in part by a grant from the University of Washington Graduate School Research Fund.
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