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Patricia Brennan Thomson Scientific January 10, 2008. How do we assess value? Current Academic Evaluation Market Role of citations, citation metrics Possibilities with new metrics – Usage Factors, H Index, Irish Research output: Summary Metrics. - PowerPoint PPT Presentation
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THOMSON SCIENTIFIC
Patricia Brennan
Thomson Scientific
January 10, 2008
THOMSON SCIENTIFIC
Research Publication and Performance
- Impact Factor Imperative?
•How do we assess value?
• Current Academic Evaluation Market
• Role of citations, citation metrics
• Possibilities with new metrics – Usage Factors, H Index,
• Irish Research output: Summary Metrics
THOMSON SCIENTIFIC
Stakeholders in Academic Evaluation
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Drivers for increased evaluation and assessment
THOMSON SCIENTIFIC
Source: National Citation Report Ireland 2003-2003Scholarship is increasingly Collaborative
Scholarly communications are changing: what is the output ?
THOMSON SCIENTIFIC
Scholarship is Global
0
200
400
600
800
1000
1200
1400
1600
1800
1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003
Year
Pape
rs w
ith N
Cou
ntrie
s
> 5 countries > 10 countries > 15 countries
>5 countries
Source: Web of Science®
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Mean Authors per Paper
0
0.5
1
1.5
2
2.5
3
3.5
4
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6
year
auth
or/p
aper
Source: Web of Science®
Scholarship is increasingly collaborative
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Largest Collaboration in 2006: 2512
authors, a “collaboration of collaborations”
Collaborations are getting broader and more complex
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What to measure? When?• Total Papers• Total Citations• Citation Impact (cites per paper)• Percent Cited Paper• Impact Relative to Field• Percentile Rank in Field • Collaboration Indicators• Expected Citation Count• Ratio of Citations to Expected citation count• Expected Citation Rate for Category• Mean / Median Citation• H Index• Citation Frequency Distribution• Time Series Trends
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Authors
Institutions
Nations
Topics
Fields
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Metrics: Individual papers1. Cites: Total citation count for selected paper.
2. Cites2: 2nd generation cite count based on total citations received by the citing articles.
3. Expected Citation Rate: An average rate of citation for all the papers of that document type (articles, reviews, letters, etc.), in that journal, for that selected year. This is a metric to evaluate citation counts.
4. Ratio: Ratio of expected cites to actual cites
5. Field: Subject area for the journal in which the paper appeared.
6. %: Percentile position of the paper based on citations in the same field.
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Metrics: Individual papers
1. Cites: Total citation count for selected paper.
Cites: 85
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Metrics: Individual papers
2. Cites2: 2nd generation cite count based on total citations received by the citing articles.
Cites: 85
Cites2: 574
THOMSON SCIENTIFIC
Metrics: Individual papers3. Expected Citation Rate: An average rate of citation for all the papers of
that document type (articles, reviews, letters, etc.), in that journal, for that selected year. This is a metric to compare peer journal papers.
Cites: 85
Cites2: 574
Expected Citation Rate: 20.8(All Articles from European Journal of
Neuroscience in 2001 received on
average 20.8 cites through year-end 2006.)
THOMSON SCIENTIFIC
Metrics: Individual papers
4. Ratio: Ratio of expected cites to actual cites
Cites: 85
Cites2: 574
Expected Citation Rate: 20.8
Ratio: 4.1
[85: 20.8 = 4.1]
THOMSON SCIENTIFIC
Metrics: Individual papers
5. Field: Subject area for the journal in which the paper appeared.Cites: 85
Cites2: 574
Expected Citation Rate: 20.8
Ratio: 4.1
Field: Neuroscience
[Note: For the multidisciplinary journals Science, Nature and PNAS,
all articles and reviews are reassigned based on the primary
category to which the article’s citing and cited journals are assigned.]
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Metrics: Individual papers
6. Percentile: position of the paper based on citations in the same field and year.
Cites: 85
Cites2: 574
Expected Citation Rate: 20.8
Ratio: 4.1
Field: Neuroscience
Percentile: 3.5%[The 85 cites to this Neuroscience
paper places it in the top 3.5% based on the citation distribution to all papers published in this field in
2001. ]
THOMSON SCIENTIFIC
Metrics for groups of papers1. Total # papers and total # cites: combined numbers for the set
2. Mean times cited: Total cites divided by total papers. [average impact]
3. Median times cited: Midpoint for citations
4. H-Index: Number of papers (N) in a given dataset having N or more citations.
5. C-Index: Sum of all actual citations divided by sum of all expected citations.
6. Average Percentile: average of the field percentile measures which are based on field and year of publication
7. Disciplinarity: reflects the level of multidisciplinarity in a set of papers, ranging from 0 to 1, where the lower the number, the greater the multidisciplinarity. (Herfindal Index)
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H-Index: Number of papers (N) in a given dataset having N or more citations.
14 papers in this set had
14 or more citations
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C-Index: Sum of all actual citations divided by sum of all expected citations.
C index = 1.98
357 180.46
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Average Percentile: average of the field percentile measures which are based on field and year of publication
Average Percentile =
31.62
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Tools for multiple workflows: Author, Researcher
• Promotion and Tenure– Author Finder– The Distinct Author Identification System (DAIS)– Citation Report– ResearchID.com
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“.. I would prefer to see something like a unique identifier for
people (so I can still get all of an author's work even if I don't know his professional history) ..”
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• Evaluating Research TeamsInitial Views and Exploration– Analyze Tool– Citation ReportProfiling Within Institutions– Journal Use ReportsA Global View– Essential Science IndicatorsDetailed and Precise Analysis– Custom Analysis
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Tools for multiple workflows: Administrators, Researchers
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Tools for multiple workflows: Librarian, Publisher
• Evaluating a journal collection:– Journal Citation Reports, – Journal Use Reports
23
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The Impact Factor Imperative
IF Calculation
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Irish Research Output: Summary Metrics
Metric Count
Total Papers 18,218
Total Cites 131,826
Mean Times Cited 7.24
Median Times Cited 2
H Index 86
Average Percentile 50.70
C-Index 1.115
Disciplinarity Indicator .01
Source: National Citation Report Ireland 2003-2003
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Irish Research Output: Comparative Output
Source: National Science Indicators 06
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Irish Research Impact: Comparative Impact
Source: National Science Indicators 06
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Irish Research Output: Summary Metrics
• Most Cited Author: Wolf K H– Cited 6143 times
Source: National Citation Report Ireland 2003-2003
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Understanding Context: Average Impact per Field
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Establishing Best Practices
• Consider whether available data can address the question
• Choose publication types, field definitions, and years of data
• Decide on whole or fractional counting
• Judge whether data require editing to remove “artifacts”
• Ask whether the results are reasonable
• Use relative measures, not just absolute counts
• Obtain multiple measures• Recognize the skewed
nature of citation data• Confirm data collected are
relevant to question• Compare like with like
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Thank You