Similar to an increase in the average SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP) levels of De Gruyter’s Open Access journals between 2015 and 2016, in 2018 the SJR and SNIP metrics has exceeded their levels for previous years, such as 2016. At the same time, cross-indicator variation in the movements and levels of these impact metrics is likely to be due to the changing composition of the Open Access journal portfolio, as represented by Scopus, and the differences in the methodology of their calculation.
A Blog Article by Pablo Markin.
The SCImago Journal Rank (SJR) indicator measures both the journal-level citation numbers and the importance of journals in which external citations appear. Similar to CiteScore, for a specific year, the SJR measure is based on an average estimation of weighted citations the journal receives during the preceding three years. Higher levels of SJR values correspond to a greater degree of journal importance. The difference between the SJR metric and the Impact Factor (IF) consists in being based on article-level average citations from the previous two-year period (Falagas, Kouranos, Arencibia-Jorge, & Karageorgopoulos, 2008).
The Source Normalized Impact per Paper (SNIP) metric was launched in 2012. This metric is calculated as a ratio of the raw impact per paper and the citation potential divided by the median database citation potential. SNIP aims to measure a contextual journal-level impact both across and within subject fields. The SNIP metric is perceived as a relatively robust journal impact measure (Moed, 2010).
In 2014, the average SJR performance of Open Access journals stood at 0.251, based on Scopus data. In 2014, the best performing Open Access journal has shown the SJR of 0.665. This figure is lower than its 2015 counterpart for Open Access titles, which indicates a tendency for improving maximum SJR level performance for the 2014-2015 period. In 2015, the best performing Open Access journal has, thus, exhibited the SJR of 0.773.
Excluding trade journal data, in 2016 the average SJR performance of Open Access journals has progressed to the level of 0.311. In 2016, the best performing Open Access journal has remarkably attained the SJR of 2.015. In 2018, the Open Access titles of De Gruyter have exceeded the average SJR performance levels of previous years. According to Scopus data, in 2018 the average SJR level of the Open Access journal portfolio has improved to 0.333.
In 2015 the average SNIP performance of Open Access journals has attained the level of 0.453. According to primary data sourced from Scopus, in 2015 the best performing Open Access journal has reached the SNIP of 1.659. The 2016 figures for the Open Access have exceeded their previous-year counterparts. Save for trade journal data, in 2016 the average SNIP performance of Open Access journals stood at 0.599. In 2016, based on Scopus information, the best performing Open Access journal has reached the SNIP of 1.887, which is lower than the level of this indicator for 2017. In 2017, the best performing Open Access journal has reached the SNIP of 2.813, which is higher than the corresponding figure for 2016.
These findings contrast strongly with the average IF performance of the current portfolio of Open Access journals that De Gruyter sports. The average IF levels have consistently increased from 0.733 in 2014 to 1.443 in 2018.
By Pablo Markin
Featured Image Credits: University of El Geneina, West Darfur, November 12, 2012 | © Courtesy of Albert González Farran/UNAMID/Flickr.
Falagas, M. E., Kouranos, V. D., Arencibia-Jorge, R., & Karageorgopoulos, D. E. (2008). Comparison of SCImago journal rank indicator with journal impact factor. The FASEB journal, 22(8), 2623-2628.
Moed, H. F. (2010). Measuring contextual citation impact of scientific journals. Journal of Informetrics, 4(3), 265-277.