. 2011 Dec 16;13(4):e123. doi: 10.2196/jmir.2012

Table 1.

Correlation coefficients

		Issue (number of papers)
		3/2009 (n = 19)		4/2009 (n = 11)		1/2010 (n = 8)		2/2010 (n = 17)		All (n = 55)
		r or rho	P value	r or rho	P value	r or rho	P value	r or rho	P value	r or rho	P value
Pearson correlation ( r )
	CitGo-Tweets^a	.57**	.01	.89***	<.001	.76*	.03	.68**	.003	.69***	<.001
	CitSc-Tweets^b	.33	.17	.74**	.01	.65	.08	.51*	.04	.54***	<.001
	logCitGo-logTweets	.42	.08	.51	.11	.72*	.045	.49*	.048	.39**	.004
	logCitSc-logTweets	.03	.90	.41	.22	.53	.17	.47	.06	.31*	.02
Spearman rank correlation (rho)
	CitGo-Tweets	.42	.07	.14	.68	.61	.11	.51*	.04	.36**	.006
	CitSc-Tweets	.06	.81	.11	.76	.44	.27	.42	.10	.22	.11

^a Citation count according to Google Scholar (CitGo) versus tweetation count (tw7).

^b Citation count according to Scopus (CitSc) versus tweetation count (tw7).

*P < .05, **P < .01, ***P < .001.