Member site Activity, posts, comments,

I have a small site with 170 members and I am trying to gauge the user/member activity. I have installed a couple plugins such as, User Activity and WP Activity, but nothing really helps to understand where or what the members are doing. This is a password only site so I can't run Google Analytics and WP Stats ins't much help. I've also looked at the server Awstats which gives the most details, pages views, number of unique users, etc. What is the best way to measure and improve member engagement? Thanks.