What do you want people to do differently?
Be really specific.
Participate more? Sure. But what specifically?
What kind of discussions and content do you want them to create? What kind of ideas do you want them to share? What do you want people to say about you to others?
When you get specific, you create a mental object.
Your members won’t have strong views about joining the conversation, but they will have views about the latest technology gossip.
That might not be a favourable attitude, but it’s still a measurable attitude. It gives you a benchmark to work from.
You can place the object (latest technology gossip) within their existing values, you can change their attitudes towards the latest technology gossip from a waste of time to a valuable source of tips. You can create emotional stories about the object, create a simple step to sharing an opinion on the gossip, share new information about the gossip.
You can build social norms around sharing the latest technology gossip. You can work to create a habit of discussing the news with relevance to their working day.
But to do any of these you need to isolate the behavior you want to change. That behavior has to be specific. That specificity creates the object. Until you have an object to work with, it’s hard to know where to even begin.