2.50
Hdl Handle:
http://hdl.handle.net/2436/620418
Title:
The Accuracy of Confidence Intervals for Field Normalised Indicators
Authors:
Thelwall, Mike ( 0000-0001-6065-205X ) ; Fairclough, Ruth
Abstract:
When comparing the average citation impact of research groups, universities and countries, field normalisation reduces the influence of discipline and time. Confidence intervals for these indicators can help with attempts to infer whether differences between sets of publications are due to chance factors. Although both bootstrapping and formulae have been proposed for these, their accuracy is unknown. In response, this article uses simulated data to systematically compare the accuracy of confidence limits in the simplest possible case, a single field and year. The results suggest that the MNLCS (Mean Normalised Log-transformed Citation Score) confidence interval formula is conservative for large groups but almost always safe, whereas bootstrap MNLCS confidence intervals tend to be accurate but can be unsafe for smaller world or group sample sizes. In contrast, bootstrap MNCS (Mean Normalised Citation Score) confidence intervals can be very unsafe, although their accuracy increases with sample sizes.
Publisher:
Elsevier
Journal:
Journal of Informetrics
Issue Date:
May-2017
URI:
http://hdl.handle.net/2436/620418
Additional Links:
https://www.journals.elsevier.com/journal-of-informetrics
Type:
Article
Language:
en
ISSN:
1875-5879
Appears in Collections:
Statistical Cybermetrics Research Group

Full metadata record

DC FieldValue Language
dc.contributor.authorThelwall, Mikeen
dc.contributor.authorFairclough, Ruthen
dc.date.accessioned2017-03-15T15:45:58Z-
dc.date.available2017-03-15T15:45:58Z-
dc.date.issued2017-05-
dc.identifier.issn1875-5879en
dc.identifier.urihttp://hdl.handle.net/2436/620418-
dc.description.abstractWhen comparing the average citation impact of research groups, universities and countries, field normalisation reduces the influence of discipline and time. Confidence intervals for these indicators can help with attempts to infer whether differences between sets of publications are due to chance factors. Although both bootstrapping and formulae have been proposed for these, their accuracy is unknown. In response, this article uses simulated data to systematically compare the accuracy of confidence limits in the simplest possible case, a single field and year. The results suggest that the MNLCS (Mean Normalised Log-transformed Citation Score) confidence interval formula is conservative for large groups but almost always safe, whereas bootstrap MNLCS confidence intervals tend to be accurate but can be unsafe for smaller world or group sample sizes. In contrast, bootstrap MNCS (Mean Normalised Citation Score) confidence intervals can be very unsafe, although their accuracy increases with sample sizes.en
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urlhttps://www.journals.elsevier.com/journal-of-informetricsen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/*
dc.subjectCitation analysisen
dc.subjectfield normalised citation indicatorsen
dc.subjectconfidence intervalsen
dc.titleThe Accuracy of Confidence Intervals for Field Normalised Indicatorsen
dc.typeArticleen
dc.identifier.journalJournal of Informetricsen
dc.date.accepted2017-03-
rioxxterms.funderInternalen
rioxxterms.identifier.projectUoW150317MTen
rioxxterms.versionAMen
rioxxterms.licenseref.urihttps://creativecommons.org/CC BY-NC-ND 4.0en
rioxxterms.licenseref.startdate2017-11-01en
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