James Fishkin's method: gather a random sample, give them balanced briefing materials and moderated small-group discussion, measure opinions before and after. It has run over a hundred times across dozens of countries.
Participants gain measurable knowledge, and — the striking finding — a single deliberative weekend produced large effects on civic engagement and voting nearly a year later. Participants came to follow politics more closely and to see their own opinions as worth having. Honest note: shifts in specific policy views often faded with time; the engagement effects are what lasted.
The deepest return on participation isn't any single result — it's what taking part does to the participant. A resident who answers one county question, sees the count, and watches the outcome close is measurably more likely to show up again, everywhere. The platform is an engagement engine wearing a budget site's clothes.
Deliberative polls use random samples and paid weekends; a self-selected county platform must be honest that its participants choose themselves — which is what the representativeness display is for.
Sources: Stanford FSI: lasting effects of deliberation · Can deliberation have lasting effects? (APSR)