Self-Selected or Mandated, Open Access Increases Citation Impact for Higher Quality Research
Figure 4
Exp(ß)-1 values for logistic regressions.
These comparisons are based on 4 models, each analyzing a different comparison range. For each comparison (e.g., 1–4 citations (lo) vs. 5–9 citations (med-lo)) an article is assigned zero if its citation count is in the lower of the two ranges and one if it is in the upper range. Then the model assigns the best fitting weights to each of the fifteen predictor variables in their joint prediction of the citation counts. The weights are proportional to the independent contribution of each variable. (Only statistically significant weights are shown.) In most of the four citation range comparisons (zero/lo, lo/med-lo, low/med-hi, lo/hi), citation counts are positively correlated with Age, Journal Impact Factor, Number of Authors, Number of References, Number of Pages, Science, Review, USA Author, OA, and Mandatedness. There is also a significant OA*Age interaction in the top and bottom range. (Citations grow with time; for age-matched articles, the OA Advantage grows even faster with time; Figure 6). OA is a significant independent contributor in three of the four models and their citation ranges, especially in the the lo/hi comparison.