Use of Telescope Statistics by Observatories

Transcription

1 Use of Telescope Statistics by Observatories Publications, Citations, and the H Index Uta Grothkopf, ESO Library

2 Overview Telescope statistics Methods overview Introducing the h index in telescope stats Use of bibliometrics by observatories

3 Telescope Statistics Publications, citations, bibliometric analyses Scientific impact of facilities Funding authorities Comparison with other facilities

4 Common Methods of Evaluation Good Bad # Publications productivity no impact # Citations impact can be inflated High-Impact Papers balanced difficult to find

5 New measure: h index Jorge E. Hirsch, UC San Diego Proc. Nat. Acad. Sci. vol. 102, (2005) Aim: quantify an individual s scientific research output

6 Definition A researcher with index h has h papers with at least h citations. index h = highest number of papers a scientist has that have each received at least that number of citations

7 h index 50 papers, 30 have 30 or more citations each: h index = 30 How to find it: list of all papers ranked by citation count h: # citations = rank #

8 Finding h with the ADS

9 Finding h with the ADS

10 Finding h with the ADS

11 Citations h index Publication number

12 Common Methods of Evaluation Good Bad # Publications productivity no impact # Citations impact can be inflated High-Impact Papers h index balanced productivity + impact difficult to find determined by years of operation

13 Applying h to observatories Methodology: collect papers that use VLT, La Silla, CFHT, HST, Keck, or Gemini data ESO papers: retrieve citations through ESO telescope bibliography others: feed bibcodes into ADS sort by descending citations find h index

14 ESO Libraries homepage / ESO telescope bibliography

15 ESO Libraries homepage / ESO telescope bibliography

16 ESO telescope bibliography, librarians interface

17 ADS: HST, CFHT

18 ADS: ESO - no search on telescopes or instruments

19 Our Sample Telescope bibliographies made available by observatories CFHT HST Keck La Silla VLT Gemini

20 Comparisons Beware! Telescope statistics are NEVER totally comparable Procedures criteria for paper selection not uniform methodologies for building telescope bibliographies vary Telescopes ground-based / space-based observatories different apertures, different wavelengths

21 h index h index CFHT HST Keck La Silla VLT Gemini

22 h index CFHT HST Keck La Silla VLT h index Gemini

23 Timeline (of our sample) 1980 CFHT 1991 HST 1996 Keck La Silla 1999 VLT 2000 Gemini

24 Parameter m m = h divided by number of years of operation (Hirsch 2005) h index 20 after 20 years m = 1 h index 40 after 20 years m = 2

25 Years since first paper / h / m Years since first paper h m CFHT HST Keck La Silla VLT Gemini

26 h and m since first paper CFHT HST Keck La Silla VLT index h Gem. 5 0 CFHT HST Keck La Silla VLT Gemini parameter m

27 / h / m # years h m CFHT HST Keck La Silla

28 h and m CFHT HST Keck La Silla 5 CFHT HST Keck La Silla 0 h index 0 parameter m

29 Conclusions h index Advantages of h index: combines productivity and impact (relatively) easy to find using the ADS not sensitive to extreme values Disadvantages: determined by # years of operation needs to be combined with m for comparison

30 Telescope Statistics Questionnaire Use of statistics by observatories Results: CFHT, Gemini, ING, Keck, NRAO, Subaru, (ESO) Chandra, HST, XMM Newton

31 Who compiles the bibliography and derives statistics? Librarians (occasional help from astronomers) ESO, Gemini, NRAO Data archive specialists Chandra Team of librarians, secretary, astronomers CFHT, HST, ING, Keck, Subaru, XMM

32 Which Statistics? How often? regularly on request never 100 % 75 % Responses 50 % 25 % 0 % Refereed publications Unrefereed publications Citations (ref. pub.) Citations (unref. pub.)

33 Mean/median Cites HIP Others regularly on request never no reply 100 % 75 % Responses 50 % 25 % 0 % Mean / median citations High Impact Papers Other

34 Which other Statistics? Average Ranking HIP h index Publications / citations per... instrument, program type, cycle, orbit etc. Most productive... instrument, program, individual author etc. across observatories: STScI internally: ESO across observatories: ESO+STScI (LISA proc.)

35 Comparisons with other Observatories? yes 60% no 40%

36 Facility/data set identifiers helpful? Yes, but......only if used widely and reliably Incentives for authors Mandatory use

37 Centralized compilation? no reply 10% no 20% By whom? yes 70% CDS, Worldwide VO, IAU... not one single institution decentralized team

38 Bibliographies publicly available? Dedicated webpage or through ADS (Filter) Collection of publication lists at ESO Library

39 ESO Libraries homepage / Other telescope bibliographies

40 ESO Libraries homepage / Other telescope bibliographies

41 Prospects Better coordination of selection criteria and methodologies Meeting? Uta Grothkopf: Use of Telescope Statistics by Observatories Santiago, August 28, 2006