Measuring the influence of a journal using impact and diffusion factors

Presents the result of the calculated ISI equivalent Impact Factor, Relative Diffusion Factor (RDF), and Journal Diffusion Factor (JDF) for articles published in the Medical Journal of Malaysia (MJM) between the years 2004 and 2008 in both their synchronous and diachronous versions. The publication data are collected from MyAis (Malaysian Abstracting & Indexing system) while the citation data are collected from Google Scholar. The values of the synchronous JDF ranges from 0.057 – 0.14 while the diachronous JDF ranges from 0.46 – 1.98. The high diachronous JDF is explained by a relatively high number of different citing journals against the number of publications. This implies that the results of diachronous JDF is influenced by the numbers of publications and a good comparison may be one of which the subject of analysis have similar number of publications and citations period. The yearly values of the synchronous RDF vary in the range of 0.66 – 1.00 while diachronous RDF ranges from 0.62 – 0.88. The result shows that diachronous RDF is negatively correlated with the number of citations, resulting in a low RDF value for highly cited publication years. What this implies in practice is that the diffusion factors can be calculated for every additional year at any journal level of analysis. This study demonstrates that these indicators are valuable tools that help to show development of journals as it changes through time.