http://ajc29.wordpress.com/2012/03/11/qualitative-vs-quantitative/#comment-63
http://camilia92.wordpress.com/2012/03/25/operationalizing-variables/#comment-47
http://itsstats.wordpress.com/2012/03/11/why-is-the-file-drawer-problem-a-problem/#comment-78
http://ryan1392.wordpress.com/2012/02/26/does-correlation-show-cause-and-effect/#comment-82