The "Tournaments" Metaphor in Citation Impact Studies: Power-Weakness   Ratios (PWR) as a Journal Indicator
  Ramanujacharyulu's (1964) Power-Weakness Ratio (PWR) measures impact by recursively multiplying the citation matrix by itself until convergence is reached in both the cited and citing dimensions; the quotient of these values is defined as PWR, whereby "cited" is considered as power and "citing" as weakness. Analytically, PWR is an attractive candidate for measuring journal impact because of its symmetrical handling of the rows and columns in the asymmetrical citation matrix, its recursive algorithm, and its mathematical elegance. In this study, PWR is discussed and critically assessed in relation to other size-independent recursive metrics. A test using the set of 83 journals in "information and library science" (according to the Web-of-Science categorization) converged, but did not provide interpretable results. Further decomposition of this set into homogeneous sub-graphs shows that--like most other journal indicators--PWR can perhaps be used within homogeneous sets, but not across citation communities. 
Loet Leydesdorff, Wouter de Nooy, and Lutz Bornmann
cs.DL