wg&sh sti2014

:

W G S H

Centre for R&D Monitoring and Dept MSI, KU Leuven

Structure of presentation

1.

2. 2.1 Regression analysis2.2 First conclusions2.3 Cross-national preference2.4 Further conclusions

3.

4.

Introduction

In this study we intend first to analyse the interrelation betweendownloads and citations of a large sample set of about 80,000 documentsput online in 2008 and downloaded/cited till June 2013. The second partof the analysis will be devoted to cross-national information flow in thesense of the notion proposed by Glänzel & Schubert (2006).

The analysis will be conducted along the following research questions.

1. Do the findings confirm earlier observations made in previousstudies (e.g., M, 2005; B ., 2006; T, 2012),concerning the correlation between the two statistics?

2. Is there a deviation of cross-national download paerns fromcross-national citations flows?

G H, Cross-national preferences, STI Leiden, 2014 3/18

Introduction

Data sources

• For the pilot study we decided to use the journal Physica A –Statistical Mechanics and Its Applications.

• To answer the first and part of the second question, download andcitation data provided by Elsevier were used. The analysis is basedon monthly counts.

• To answer the second question concerning cross-national citationpreferences, data extracted from Thomson Reuters WoS were used.Citations are based on a 3-year window.


Methods and results

Evolution of downloads and citations

The evolution of downloads and citations for the complete set and thejournal Physica A was analysed using the mean values over documents.

The number of downloads has been divided by 100. This ‘scale factor’ isin line with the findings by M (2005).

☛ As expected, both paerns show parallel evolution, where downloadsstart and increase earlier than the corresponding citation rates.


Methods and results

Monthly evolution of downloads vs. citations for the complete set (le) andPhysica A (right)

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Data source: Elsevier Bibliometrics Research Programme (EBRP)


Regression analysis

Regression analysis

Unlike in previous studies on this issue, in the present study we usedconditional expectations (here: condition = [downloads/100]) for theregression analysis (cf. G ., 2004).

• The correlation is rather strong (r > 0.95).

• The slope shows that download frequency is roughly by two ordersof magnitude larger than citation rates (about 100 for the journaland about 70 for the complete set including life sciences,engineering and mathematics).


Regression analysis

Conditional mean citation rates as a function of downloads five years aer onlineavailability for the ‘complete set (le) and Physica A (right)

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First conclusions

• The first results partially confirm results of earlier studies M(2005), B . (2006), O’L (2008), L (2011) and T(2012), who found significant positive correlation between citationsand downloads in several fields in the sciences.

• In this context, it should be mentioned that using the number ofdownloads as the condition, by no means implies causality.☛ This is in line with observations by M (2005) and S .

(2011), who stressed in contrast to the results of other authors (e.g.,B ., 2006, who suggested the use of downloads as earlypredictors of citation impact) that no conclusions might be drawn onthe possible effect of early downloads on later citation rates of a paper.


Cross-national preference in downloads and citations

This is based on the idea of analysing country-by-country cross-referenceand cross-citation networks (G S, 2005; S G, 2006).

• In particular, we compare the paerns found in citation analysiswith similar results from download statistics on Physica A.

• We expect deviating paerns since, unlike citations, downloadingscientific documents is not necessarily linked to the production andpublication of new research results.

Data have been normalised by the total number of downloads and citationsrespectively. Thus a direct comparison across countries and between nationaldownload and citation paerns is possible.



National shares in all downloads/citations of the 15 most active countries basedon the journal Physica A

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AUS BRA CHN DEU ESP FRA GBR IND IRN ITA JPN KOR POL TWN USA

Downloaded Downloading Cited Citing




Statistics on cross-national preferences and similarities in downloads andcitations are broken down by downloaded, downloading, cited and citingcountries.

• A cosine measure is used to capture similarities.

rij =pij√pi · pj

• Note that this measure reflecting downloads (citations) from (to)papers from country i in country j is asymmetric.

• The value pij = 0.05 was used as lower threshold for display.



Cross-national similarity in downloads (top) and cites (boom) for 25 countries (Physica A)[row vector: downloaded/cited country, column vector: downloading/citing country]

Country ARG AUS BEL BRA CAN CHE CHN DEU ESP FRA GBR HUN IND IRL IRN ISR ITA JPN KOR MEX POL PRT TUR TWN USAARG 0.13 0.06 0.07 0.06 0.15 0.07 0.11 0.07 0.08 0.07 0.15 0.05 0.07 0.12AUS 0.11 0.15 0.08 0.11 0.07BEL 0.06 0.08 0.07 0.06 0.09BRA 0.23 0.11 0.08 0.13 0.06 0.09CAN 0.06 0.06CHE 0.09 0.15 0.05 0.09 0.07CHN 0.05 0.06 0.49 0.05 0.09 0.07 0.19 0.07 0.05 0.07 0.08 0.15DEU 0.07 0.07 0.05 0.07ESP 0.09 0.09 0.06 0.07FRA 0.09 0.06 0.12 0.07 0.07 0.10GBR 0.10 0.10 0.06 0.08HUN 0.07 0.08IND 0.17 0.06 0.06 0.34 0.11 0.05 0.06 0.10IRL 0.05 0.18 0.06 0.11 0.06 0.06 0.14 0.08 0.06 0.10IRN 0.05 0.34 0.07ISRITA 0.05 0.06 0.15 0.06 0.06 0.06 0.08 0.06 0.15 0.10 0.06 0.05 0.08 0.14JPN 0.14 0.06 0.09 0.14 0.08KOR 0.14 0.11 0.12 0.20 0.06 0.08MEX 0.08 0.09 0.06 0.06 0.06 0.07 0.09 0.14 0.12POL 0.05 0.06 0.08 0.19 0.07 0.05 0.05 0.10 0.06 0.28 0.09 0.11 0.09 0.17PRT 0.06 0.07 0.20 0.06 0.05 0.11 0.06 0.15 0.06 0.05 0.11 0.07 0.06 0.15TUR 0.20TWN 0.10 0.06 0.15 0.05 0.11 0.06USA 0.06 0.19 0.06 0.06 0.12 0.12 0.07 0.05 0.18

Country ARG AUS BEL BRA CAN CHE CHN DEU ESP FRA GBR HUN IND IRL IRN ISR ITA JPN KOR MEX POL PRT TUR TWN USAARG 0.35 0.09 0.13 0.23 0.06 0.05AUS 0.19 0.24 0.12 0.09 0.08 0.12BEL 0.32 0.08 0.09 0.11 0.11 0.07 0.06 0.26BRA 0.46 0.06 0.06 0.11 0.09 0.19CAN 0.31CHE 0.13 0.36 0.10 0.07CHN 0.10 0.09 0.05 0.78 0.08 0.05 0.06 0.06 0.06 0.06 0.06 0.25DEU 0.05 0.05 0.08 0.23 0.07 0.07 0.16ESP 0.33FRA 0.09 0.07 0.21 0.15 0.41 0.11 0.14 0.06 0.06 0.21GBR 0.05 0.12 0.06 0.06 0.24 0.11 0.05 0.30HUN 0.07 0.08 0.08 0.13 0.17 0.05 0.17 0.12 0.16IND 0.30 0.07IRL 0.08 0.06 0.09 0.08 0.16 0.05 0.24 0.18IRN 0.09 0.42 0.06ISR 0.05 0.07 0.08 0.16 0.32 0.05 0.15ITA 0.07 0.09 0.06 0.06 0.07 0.12 0.40 0.05 0.43JPN 0.08 0.43 0.09 0.12KOR 0.12 0.09 0.08 0.08 0.16 0.09 0.07 0.05 0.28 0.06 0.08 0.22MEX 0.08 0.08 0.05 0.07 0.45 0.18POL 0.05 0.06 0.07 0.05 0.05 0.06 0.11 0.06 0.44 0.12PRT 0.09 0.07 0.07 0.06 0.08 0.17 0.05 0.06 0.21 0.14TUR 0.33TWN 0.09 0.09 0.08 0.06 0.06 0.07 0.06 0.39 0.14USA 0.07 0.11 0.09 0.15 0.12 0.12 0.07 0.11 0.16 0.06 0.10 0.12 0.05 0.95

Data source: Elsevier Bibliometrics Research Programme (EBRP) and Thomson Reuters Web of Science (WoS)


Further conclusions

• The domestic activities represented by the main diagonal are quitedominant in both cases.

• Enormous downloading activities of China and the US could beobserved.

• Striking but completely deviating divergent paerns were observedfor Israel and Iran.

• Germany’s and France’s overall property of being more active incitation flows than in download activities is also reflected thecross-national similarities.

• Geopolitical location, cultural relations and language beingdetermining factors in shaping preferences in cross-citations (cf.S G, 2006) are somewhat less pronounced incross-download relations.


Summary and discussion

Main findings of the study• Downloads are

1. of about two orders of magnitude more frequent than citations in aninitial phase, and

2. rather strongly correlated with citation statistics.

• Downloads are not closely related to documented scholarlycommunication as citations are by nature. Documents might bedownloaded by anybody who has access without using orincorporating downloaded information in own publishable research.


Summary and discussion

General limitation of this study☛ Since articles might already be available as online-first versions or

accessible via institutional or individual repositories, downloads ofor citations to early or ‘in-press’ versions can indeed affect responseindicators. However, there is no evidence of systematic or seriousdistortion of download and citation processes.


Acknowledgements

AcknowledgementsThe authors acknowledge the use of data provided by Elsevier in the frameworkof the Elsevier Bibliometrics Research Programme (EBRP).

*

We wish to thank M L and H M for their initiative and theirvaluable input.


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