Spearman correlation coeffiecents for dbViz and Rhino.
  dbViz Rhino
Metric c-ns c-s nc-s nc-ns c-ns c-s nc-s nc-ns c-ns+d
SFC 0.38 0.38 0.38 0.38 0.62 0.62 0.62 0.62 0.62
SFC' 0.35 0.35 0.35 0.35 0.58 0.58 0.58 0.58 0.58
TFC
0.52 0.13 0.15 0.15 0.38 0.35 0.35 0.37 0.38
TFCmax 0.5 0.23 0.21 0.21 0.52 0.51 0.5 0.5 0.5
HFC 0.49 0.47 0.47 0.47 0.44 0.42 0.41 0.43 0.44
c-ns: comments, no stemming c-s: comments, stemming
nc-s: no comments, stemming nc-ns: no comments, no stemming
c-ns+d: comments, no stemming, external documentations
All correlations are statistically significant at the 1% level.
The sample size (number of feature pairs) is 78 in dbViz and 84,255 in Rhino.
HFC uses weights of 0.5 for both structural and textual information.