scopus search strategies ___________________________________. arthur eger msc, customer develop...

Scopus Search Strategies___________________________________

.

Arthur Eger MSc, Customer Develop Manager

Elsevier

Dr. Eric Sieverts, consultant Utrecht University

August 2010

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Some reasons for generic search strategies

Hagelund and Olsson, 2008:

The search methodology of researchers can be characterized by “trial and error”

They have no planned search strategy, but start at random, experimenting both with the actual words and sources to use.

Even if they are unsuccessful or fail to understand what went wrong, they never use manuals, etc. for instructions

The idea of contacting the library for help does not occur to them They have little or no knowledge of the finer points of many information

sources Subject searches are seldom performed, and when attempted,

researchers have difficulties in identifying correct search terms Searches are often unsuccessful

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how to do better searches

basic types of search strategies – quick & easy search– building blocks and some variations– limit/refine your search– expand your search– pearl-growing (or snow-balling)

what may be "killing" your results– prevention of missing important things – prevention of retrieving irrelevant stuff

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preliminary

general starting points, whatever strategy you choose:– just think before you type– make some conceptual analysis:

1. write your problem down in a sentence

2. what words represent the constituing elements for your subject?

3. which element is most vital (and which next)?– think about some proper search terms (other than those words

jotted down already)

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• Select the Scopus database

• Compose a simple query using a few important terms linked by AND or OR operators

• Display abbreviated records

• Modify with simple changes as needed

• Print complete records retrieved

Source: Harter, 1986 and Wagners, 1989

“Quick-and-easy” searches

For problems with few concepts that can be expressed with few words or phrases that are

not too common

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“…” is searching for adjacent words

* (truncation) retrieves e.g. personality, personalities, personalisation

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The Results-list shows the four articles located in Scopus

Now examine the results:

• are any results relevant?

• are there other terms you could add to the search statement or use as substitutes e.g. pets or “human-cat interactions”?

• can you think of other ways to express the topic e.g. (human cat relations*) or (cats as pets) and owner? (Siamese cats) or (Burmese cats)

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To view a document in your search

results, click the Abstract + Refs

button.

Links to full text and other library services are customizable and

depend on how Scopus has been set up at your institute.

Now examine the results

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Print the complete records retrieved

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Print the full text document

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• Determine the main elements or concepts associated with your problem (in somewhat more detail than before)

• Write characteristic words for them, next to each other

• Think of synonyms or alternatives for these words

• Write these words under the corresponding concepts

Sample: Find articles on modern town planning in The Netherlands:

The “building blocks” approachThe most widely used online

searching strategy

Town planning Modern NetherlandsTown planningUrban planning

Urban designCity planning

ModernContemporary

Current20th century

Twentieth century

NetherlandsHollandDutch

Amsterdam Rotterdam

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• Formulate queries based on the elements or concept groups, “OR”-ing synonyms, using controlled or free vocabulary

• Retrieve individual result sets for each element or concept group

• Combine systematically retrieved sets with Boolean operators (mostly AND) to build a solution set for the whole problem

The “building blocks” approachThe most widely used online

searching strategy

Architecture Modern Netherlands

Town planningUrban planning

Urban designCity planning

ModernContemporary

Current20th century

Twentieth century

NetherlandsHollandDutch

Amsterdam Rotterdam

OR OR

AND AND

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The “building blocks” approachCombine terms for each element with Boolean

“OR” operators

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The “building blocks” approachCombine the building blocks with Boolean

“AND” operators

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The “building blocks” approachCombine the building blocks with Boolean

“AND” operators

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Building blocks: but start with only one

if one of your concepts is expected to be very specific and to produce a limited number of results:

– just start with searching for only this element– see whether the number of results is manageable– see whether the results are already sufficiently focused

if not– continue with the next most specific or essential element– combine with AND– and inspect results again– …. (etc.)

• works especially well if your main concept already implies the others• prevents missing relevant results by limiting with incorrect terms

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Building blocks: but start with only one

sample search:

the dutch "woonerf"-concept in modern town planningthe very specific term "woonerf" alone gives already a satisfactory result

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Building blocks: limit/refine your search

• when the combined set is obtained, inferences can be made about precision and recall by adjustments of individual concepts or how these concepts are combined

• use Refine Results, to customize the results by limiting to certain categories of documents. For example, limit to documents from a certain source, by a certain author, or published in a certain year.

• for most categories, Scopus displays the number of results associated with such refinements

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Building blocks: limit/refine your search

if the results seem to be not sufficiently focused yet, despite having combined all required concepts already

check whether AND-combination of terms result in "false coordination"– replace AND-relation by "exact phrase" or proximity search

– modern AND "town planning" >> "modern town planning"

– modern AND "town planning" >> modern W/5 "town planning"check whether a term is too common in almost any general research

description– limit that term to Title- or Keyword-field to ensure that it is the real subject

check whether your terms occur in other (unwanted) context– refine with additional term(s), characteristic for your context (AND-relation)

– refine by excluding characteristic term(s) for the unwanted context (NOT-relation)

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Building blocks: expand your search

inspect your results to see whether you can identify relevant terms which you did not yet use in your search

– words in titles– keywords– words in abstracts

add them to the pertinent building block apply an OR-relation within the block apply again your AND-relations between the blocks

in case a hiërarchical thesaurus is available: explode thesaurusterm with narrower terms otherwise invent more specific additional terms yourself

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• Begin with a specific document or document set that is known to be relevant (the “pearl”)

• Use the characteristics of the “pearl” to successively grow a set of related documents : Use assigned index terms, title- or text-words, names, citations, publication data, or structural and statistical properties to formulate queries to retrieve subsequent sets

The most difficult problem is to determine the “pearl” and to determine when to stop forming and growing subsequent sets.

Source: Markey & Cochrane, 1981

The “pearl growing” approach

Method highly dependant on interaction between the searcher and the system

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The “pearl growing” approachUsing one good article to search for others is a

strategy based on the assumption that articles on the same topic are assigned the same descriptors

Begin with a known article (the “pearl”)

Display the “Abstract + Refs” section to examine the index terms

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The “pearl growing” approachTo find any more articles like the “pearl”, use the

Index Keywords provided

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The “pearl growing” approachYour strategy could be:

The search retrieves 87 papers, including the “pearl”

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• Begin with a large subset of the entire database

• Successively pare the large subset down with concepts specific to the problem

Source: Meadow & Cochrane, 1981

The “successive fractions” approach

Works well with problems that are vague or broad because it

simplifies the research process by breaking it into a sequence of systematic and discrete steps

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Begin with creating a large subset of the entire database


Works well if you are unfamiliar with the literature on this topic vague or broad because

If you are searching for a phrase which contains the word "and," omit the word

"and" from your search. For example: profit loss would find the phrase "profit and loss"

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Successively pare the large subset down with concepts specific to the problem

After browsing through the Results-set apply a variety of restrictions and combine any one of these topics with the original set

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Successively pare the large subset down with concepts specific to the problem

1st restriction

2nd restriction

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• Begin with a comprehensive set of documents generally related to the problem area by retrieving a large set of documents using one or a few general terms

• Scan the documents and note key features of the problem e.g. authors, terminology, methods

• Use the noted features to formulate and pose successive queries that further clarify the problem

• As understanding of the problem progresses, documents or sets are printed or saved as part of the final resultant set.

Source: Hawkins and Wagner, 1982

Interactive scanning

For problems in domains unfamiliar to the searcher

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• Begin by retrieving a reasonable set of (mostly relevant) documents

• Form a second set, using a somewhat different approach

• Use the NOT operator to find the difference between the two sets: "what is new in the second set compared to the first one?"

• If the difference contains no (or only a few) relevant records, the search process is finished; otherwise the new results are added and search continues with alternative approaches

Source: Vigil, 1983

“Closed-loop relevance clustering

To remind the searcher of the uses and limitations of the seldom-used NOT operator

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why you may have missed important (relevant) results

• query has been over-specified (redundancy in AND-relations) remedy: omit least important or implicit building block

• spelling mistake in a search term remedy: check interim results & expected yields to find the bad

guy

• relevant results may contain variations in spelling and wordforms (polarisation - polarization ; behaviour - behavior ; sequence - sequencing - sequential ; three-dimensional - 3-dimensional)

remedy: use proper wildcards and truncation

• you may have missed common synonyms remedy: scan your results; use synonym finder (thesaurus.com, answers.com, synonym-finder, roget)

• there may exist very many possible search terms for a generic concept

• using "exact phrase" search may have been too limiting

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why you may have missed important (relevant) results

• query has been over-specified (redundancy in AND-relations)

• spelling mistake in a search term

• relevant results may contain variations in spelling and wordforms

• you may have missed common synonyms

• there may exist very many possible search terms for a generic concept remedy: no generic solution exists-- try still to invent some additional terms-- leave the concept out if it is too vague or too broad and can be expressed in too many different ways(applications of …, developments in …, importance of …, influence of

…)

• using "exact phrase" search may be too limiting (with "aesthetic surgery" you will have missed "aesthetic facial surgery" or "aesthetic and reconstructive surgery")

remedy: use proximity instead (aesthetic w/4 surgery)

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why you may have retrieved irrelevant results

• query unsufficiently specifiedremedy: add a missing concept/building block (AND-relation)

• false coordination between search terms in the documentremedy: use exact phrase or proximity operator (instead of

AND)

• word has unwanted meaning as well (homograph) remedy: limit to required context by additional concept

• not sufficiently specific search term(s) have been usedremedy: try to replace the bad guy(s) by narrower one

• documents contained (too) much searchable text (too long abstracts or full-text searchable articles)

remedy: limit search to only title / keywords / (abstract) fields

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but be aware ….

• most things you can do to improve the recall (less misses)

tend to somewhat deteriorate the precision (more noise)

• most things you can do to improve the precision (less noise)

tend to somewhat deteriorate the recall (more misses)

nevertheless:

be inventive, since improvement is always possible

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