Manual and preview: lowest abandon risk
Manual (click-to-call) and preview dialing put a human in the loop before or as the call connects, which keeps abandon rate near zero — the tradeoff is lower call volume per agent-hour.
Progressive and power: pacing to agent availability
Progressive dials one number as an agent becomes free; power dials a fixed ratio ahead of agent availability. Both increase throughput over manual/preview but introduce nonzero abandon risk that needs to be monitored against jurisdictional limits.
Predictive: highest throughput, highest compliance load
Predictive dialing uses statistical pacing to dial ahead of agent availability based on projected answer and handle-time rates. It delivers the highest agent utilization of the six modes, and it is also the mode where abandon-rate fraud gating and a kill switch matter most — a pacing miscalculation directly creates compliance exposure.
Robo (IVR-broadcast): consent is the whole story
Robo dialing plays a pre-recorded message via IVR with no live agent required. This is the mode most tightly bound to TCPA prior-express-consent requirements — one-to-one consent matching is not optional here, and jurisdictional rules on robocalls vary significantly.
Can the vendor tell you — in one sentence — which of their AI capabilities are rule-based, which are generative, and which are still roadmap?