The best way to start evaluating worship is to focus the mission goal of worship. Growing churches diversify worship options, not by style or time of day, but my mission purpose. Is it healing worship? Coaching worship? Educational worship? Transformational worship? Care giving worship? Inspirational worship? Mission connectional worship?
Sometimes you can measure life changes “on the spot”. Count how many people are smiling after worship; how many linger for small groups or significant conversations; how many people are actually healed in some way; how many take away flowers to visit the sick.
Sometimes you can measure “stories”. Count how many stories of life transformation, new insight, impassioned dialogue, or mission participation are shared during coffee hour, on your website, or worship leaders (including choir and band members, ushers and greeters, refreshment servers).
Sometimes you can measure through surveys. Test the growth in Biblical literacy among members; their understanding and participation in social issues. Count the number of new individuals or families in worship, or the number of clear personal invitations by members to friends, neighbors, and work associates to attend worship.
Your mission is what you measure! Most traditional churches think worship is educational (in scripture, theology, and mission issues), but never find out. They regularly have healing prayer, but nobody is healed. They coach about faith and lifestyle, but nobody changes their behavior. They glorify God, but there is no joy in church meetings, expectation for grace in funerals, or witness to Christ at work. Could it be that the real mission of worship is simply to reduce guilt, have fun, and feel content?