The Annual Survey
Some platforms have great survey features which let you continuously survey a random sample of members each month and track results over time.
This is a great way of showing not just the improvement you’re making in the community, but also running multi-regression analysis to determine which metrics are strongly associated with the key metrics you want to move.
If you’re tracking member satisfaction, you can analyze whether things like time to first response, number of accepted solutions, number of questions/responses etc…are the biggest drivers of the results you want to see.
Once you know that, you know which metrics to focus on moving (this becomes the basis of your engagement plan).
If you don’t have this, I suggest you run an annual survey. Use the same questions each year. Track the results over time. It might be one of the simplest ways to prove the improvement you’re making within the community each year.