Number of comments per issue. Discussion is occuring openly - could also indicate level of agreement.

SELECT avg(avg_num_comments), project_name
FROM
(
	SELECT count(comment_id) as avg_num_comments, projects.name as project_name, projects.id as project_id
	FROM msr14.issue_comments
		join issues on issue_comments.issue_id = issues.id
		join projects on issues.repo_id = projects.id
	GROUP BY projects.id, issues.id
) as comments_per_issue
GROUP BY project_id