Journal Evaluation Research Based On Improved Z-index

Journal evaluation is an important research area of Library and Information Science,and a fair and reasonable evaluation mechanism can effectively promote the healthy operation of scientific research activities.Since the American intelligence scientist Garfield founded the Science Citation Index and Impact Factor in the 1970s,quantitative research in metrology based on citation analysis has become the mainstream evaluation method in the field of journal evaluation.After entering the new millennium,the h-index has been widely used due to its simplicity and effectiveness.The z-index is a Quality-Quantity-Consistency ternary composite index developed on the basis of the h-index,and innovation has been reflected in its evaluation practice.This study found that the z-index failed to measure the time factor of journal citations,and the citation consistency also made the index lack of evaluation stability.Based on the citation time lag and citation distribution,the z-index was revised,and a new journal evaluation index—z_tu-index was proposed.In order to verify the validity and scientificity of the z_tu-index in the field of journal evaluation,this article takes the citation data of 33 high-quality journals in the field of Web of Science Information Science and Library Science as the empirical research object,and conducts in-depth research through comparative analysis and statistical analysis on journal evaluation performance of indexes such as z_tu-index,z-index,p-index,h-index and impact factor.The research result shows that the z_tu-index has a good correlation with traditional journal evaluation indicators.On the basis of inheriting the advantages of the z-index high sensitivity and high discrimination,it also reflects its own characteristics:with the help of the corrected citations,z_tu-index weakens the weight of the citation and shifts the evaluation focus to the quality factor,which helps to screen small-scale and high-quality journals;the introduction of low-core citation ratios enables the z_tu-index to effectively avoid the interference of outliers on index calculation and thus strengthens the appraisal versatility and stability of the index.