Haal meer uit gewone zoekmachines

Haal meer uit gewone
zoekmachines
Wouter Gerritsma, Vrije Universiteit
VOGIN
Informatie overload? Verminder je de recall!
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Gebruik minder database(s) (delen)
Limiteer op taal
Limiteer op publicatiejaar
Limiteer op velden
Gebruik nabijheidsoperatoren i.p.v. AND
• Gebruik specifiekere termen
• Voeg een aspect toe
Gebruik andere database delen
• Google.nl, Google.com, Google.co.uk
– books.google.com
– scholar.google.com
– patents.google.com
• Bing.com vs academic.research.microsoft.com Be warned
Limiteer op taal of regio
• Via de advanced search
Limiteer op periode
• In Google Scholar
Pas op met sort by date
• In Google patents
• In Google
– [“water management” 2000…2010]
Zoek in specifieke velden (ti,kw,ab)
• [intitle:”water management”]
• [allintitle:water management]
– Werkt precies zo in Google Scholar
• [intext:”water management”]
• [allintext:water management]
Nabijheidsoperatoren in Google
• [“water management” “technology assessment”]
• [“water management” AROUND(5) “technology
assessment”]
– Vooral effectief om relevante lange teksten te vinden
– Werkt helaas niet in Google Scholar!
Gebruik specifiekere term
• ["heart disease" "heart attack"]
• ["heart disease" "myocardial infarction"]
• Op zoek naar professionele termen?
– [chocolate thesaurus|glossary|dictionary]
Voeg een aspect toe
• ["water management"]
• ["water management" "technology assessment"]
Boolean en Google: haakjes werken niet!
OR gaat voor AND!
• a b OR c d
• a AND (b OR c) AND d
• a OR b c OR d
• (a OR b) AND (c OR d)
• [library technology OR systems]
• [kinderen OR jongens OR meisjes OR tieners OR pubers dik OR
zwaarlijvig OR zwaar OR overgewicht ziek OR ziekelijk OR ziekte OR
ziektebeeld]
Additionele operatoren
• site:[bibliotheek site:wageningenur.nl]
– [site:*.nasa.* inurl:education]
• ext:[crinipellis perniciosa ext:pdf]
Specifiek Google Scholar
General Google Scholar syntax
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Use ["phrase searching"]
Search for file type ["land degradation" ext:doc]
Search for specific domains ["land ownership" site:.ac.uk] !!!
Search in titles [allintitle:anatomy plants water]
Search with OR ["carbon dioxide" OR CO2]
Exclude terms ["nutrient cycling" –nitrogen]
Combine ["carbon dioxide" OR co2 intitle:"nutrient cycles" phosphorus ext:pdf]
Pas de settings aan!
• Search results
– Number of results : 20 max
– Open in a new window
– Choose the right reference manager
• Languages
– Also in available in Dutch
• Library links
– Choose link resolver of your University
Searching for recent literature!
• Use publication years
– In the advanced search
– Or use the facets in search result
– Sort by date???
• Inclusion of word variants is unclear. (Google Scholar has a
smaller dictionary than Google.com)
• No verbatim search, but phrases do work! ["behaviour"]
• Parentheses () do not work in Google (Scholar)!
Search engine result page
• Ranking influenced by citations (older articles on top!)
Alerts galore
• For searching GS strings must be kept under
256 characters.
• For alerts GS strings must be kept under 100
characters
• My updates : Alerts based on the topics of
your publications (different from my Citations)
My Citations & My Library
• My Citations
– Your personal profile page, concentrating on publication lists and
citations.
– Identifies you co-author network
• My library
– Your saved articles
– Also lists all your references "cited by me"
– No plugin for word processors (yet)
Google Scholar quality
• Coverage is still unclear
– Coverage is constantly growing, probably the most
comprehensive scholarly literature database (Harzing, 2014. Scientometrics 98 (1):
565-575. http://dx.doi.org/10.1007/s11192-013-0975-y)
– Not all OA repositories are (fully) indexed
(https://atmire.com/website/?q=content/google-scholar-and-dspace)
– Concentrates on scientific articles, share of books is growing,
Grey Lit from repositories partially included
• For systematic reviews Pubmed alone is insufficient,
complementary searches in GS and other indexes are a
necessity
• Metadata sometimes problematic, the version function
under the snippet helps
(Bramer, et al. 2013. Systematic Reviews 2 (1): 115. http://dx.doi.org/10.1186/2046-4053-2-115)
Google Scholar and Google
• Google and Google Scholar are separate indexes!
• Google Scholar results are pushed in Google when searching for
scientific subjects
– Make use of that reminder!
– But not the other way around
• Some repositories are covered by Google but not in Google Scholar, or
partly covered in Google Scholar
– Google Scholar [site:edepot.wur.nl]
– Google [site:edepot.wur.nl]
Google scholar is getting better at metadata
• https://scholar.google.com/scholar_lookup?doi=10.1126%2Fscience.1152509
&issn=0036-8075&issue=5857&journal=SCIENCE&hl=en&pages=17371742&pmid=18079392&title=Coral%20reefs%20under%20rapid%20climate%
20change%20and%20ocean%20acidification&author=O%20HoeghGuldberg&publication_year=2007&volume=318
• https://scholar.google.com/scholar_lookup?doi=10.1126/science.1152509
• https://scholar.google.com/scholar_lookup?issn=00368075&issue=5857&pages=1737-1742&author=HoeghGuldberg&publication_year=2007&volume=318
Bronnenkennis
Wouter Gerritsma, Vrije Universiteit
VOGIN
Wetenschappelijk zoekmachines
• Google Scholar
• Microsoft Academic Search
• DeepDyve
• Defunct: SciRus
Bibliografiën/metadazoekmachines
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PubMed http://pubmed.gov/
Eric http://www.eric.ed.gov/
LISTA http://www.libraryresearch.com/
WorldWideScience http://worldwidescience.org/
Boeken
Catalogi
• Bibliotheek catalogi bijv: http://library.wur.nl/WebQuery/clc/
• Open worldcat http://www.worldcat.org/
• Hathi Trust http://www.hathitrust.org/
• DOAB: http://www.doabooks.org/doab
Fulltext boeken zoekers
• Google Booksearch http://books.google.com/
• Hathi Trust http://www.hathitrust.org/
E-books aggregators
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Proj Gutenberg http://www.gutenberg.org/wiki/Main_Page
Online Books Page http://onlinebooks.library.upenn.edu/
Internet Archive texts http://www.archive.org/details/texts
Gallica, Bibliothèque Numérique http://gallica.bnf.fr/
Freebooks for doctors http://www.freebooks4doctors.com/
Open Access Journals
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DOAJ http://www.doaj.org/
Open J-Gate http://www.openjgate.org/
LivRe! http://livre.cnen.gov.br/Default2I.asp
PubMed Central http://www.pubmedcentral.nih.gov/
Highwire Press http://highwire.stanford.edu/
Elektronische Zeitschriftenbibliothek EZB http://rzblx1.uniregensburg.de/ezeit/index.phtml?bibid=AAAAA&colors=7
OA repositories
OAI metadata zoekmachines
• Narcis http://www.narcis.info/index
• BASE http://www.base-search.net/
• OAISTER: http://oaister.worldcat.org/
• ArXiv http://arxiv.org/
• Driver http://www.driver-repository.eu/
Directories of repositories
• ROAR http://roar.eprints.org/
• openDOAR http://www.opendoar.org/
Research data
Research data repositories NL
• DANS https://easy.dans.knaw.nl/ui/home
• 3TU.Datacentum http://datacentrum.3tu.nl/
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Data portal
• Datacite http://search.datacite.org/ui
• Narcis http://www.narcis.nl/search/coll/dataset/Language/en searches DANS,
3TU.Datacentrum, the Language Archive and datasets from Tilburg University,
Wageningen University, MPI, DANS-KNAW and CentERdata
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Directories of research data repositories
• Re3Data (in opbouw) http://service.re3data.org/search/
• OAD http://oad.simmons.edu/oadwiki/Data_repositories
Grey Literature
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Greynet http://www.greynet.org/
Grijze Literatuur in Nederland (GLIN) http://picarta.pica.nl/xslt/DB=3.2/
GreySource http://www.greynet.org/greysourceindex.html
OpenGrey http://www.opengrey.eu/
Dissertaties en Proefschriften
• NDLTD http://www.ndltd.org/find (met verschillende suggesties)
• DART Europe http://www.dart-europe.eu/basic-search.php
• Narcis http://www.narcis.nl/search/coll/publication/genre/doctoralthes
is/Language/en
Patenten
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Patenten databases
USPTO http://www.uspto.gov/patft/index.html
Espace http://ep.espacenet.com/
WIPO http://www.wipo.int/pctdb/en/search-adv.jsp
Patenten zoekmachines
Google patent Search http://patents.google.com
Cambia patent lens http://www.patentlens.net/ (life science
patenten)
Databases
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Genbank http://www.ncbi.nlm.nih.gov/Genbank/index.html
PubChem http://pubchem.ncbi.nlm.nih.gov/
UniProt http://www.ebi.ac.uk/uniprot/index.html
Database issue van NAR database overzicht.
Wetenschappelijk nieuws
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Eureka Alert http://www.eurekalert.org/index.php
News@Nature http://www.nature.com/news/index.html
Science Daily http://www.sciencedaily.com/
SciCentral http://www.scicentral.com/
Scientific
American http://www.sciam.com/news_directory.cfm
• New Scientist http://www.newscientist.com/news.ns
• Noorderlicht http://noorderlicht.vpro.nl/
Source: http://deepwebtechblog.com/the-deep-web-is-not-all-dark/
Oorzaken van het diepe Web
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De informatie zit in databases
Zoekmachine limiteringen
Website limiteringen
Cognitieve factoren
Web 2.0
Het databases probleem
• Inhoud van databasese moeilijk te indexeren
– Zoekmachines zien een invulscherm
– Zoekmachines zien een “zoek” knop
• Database inhoud niet geoptimaliseerd voor WWW, records
ranken lag
• Dit speelt ook met onze catalogi en repositories (Arlitsch, K., & O'Brien, P. S.
(2012). Invisible institutional repositories: addressing the low indexing ratios of IRs in Google. Library Hi
Tech, 30(1), 60-81. http://dx.doi.org/10.1108/07378831211213210)
Zoekmachinelimiteringen
Bron: http://drunkmenworkhere.org/219 (2006)
Websitelimiteringen
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Robots.txt op de root directory
Sitemap.xml voor grote sites
Gebruik van javascript
File formats zoals zip, flash worden niet/nauwelijks
geindexeerd
• Tekst files zijn niet ge-ocr’d
Cognitieve factoren
• Mensen kijken niet verder dan hun neus langs is
• Bladeren niet voorbij de standaard 10 resultaten op 1e SERP
Web 2.0
• Social media has exploded since 2005
• Large social media sites (Facebook, Instagram are
closed/partially closed platforms)
Oplossingen voor databases
• Zoek databases waar je ze kunt verwachten
– CBS verzamelt statistieken en heft Statline, CBS in uw buurt
• Zoek naar databases over het onderwerp met als
additionele termen woorden die naar databases verwijzen
zoals: database, data, dataset, archive, bibliography, index,
directory, register, zoek, search of statistics
• ["plane crash" | "aviation accidents" database].