Preview, progressive and predictive dialing compared
Outbound dialing modes describe how a system paces calls to agents. In preview dialing the agent sees the record and chooses when to dial. In progressive dialing the system dials the next number automatically as soon as an agent is free, one call per agent. In predictive dialing the system dials several numbers per agent in anticipation of some not answering, which raises agent utilisation but introduces the risk of abandoned calls.
How the three modes differ
| Preview | Progressive | Predictive | |
|---|---|---|---|
| Who starts the call | The agent | The system, when an agent is free | The system, ahead of agents being free |
| Calls per available agent | One | One | More than one |
| Agent idle time | Highest | Moderate | Lowest |
| Risk of abandoned calls | None | None | Yes — the core trade-off |
| Agent preparation | Full — reads the record first | Brief — context appears as it connects | Brief |
| Best for | High-value, complex or sensitive calls | Most standard outbound work | High-volume, low-complexity, large lists |
What is an abandoned call, and why does it matter?
An abandoned call is one where the customer answers and no agent is available to speak to them — the person picks up to silence, or to a disconnect. It is a structural consequence of predictive dialing: if you dial more numbers than you have agents, some answered calls will have nowhere to go.
This is regulated in many jurisdictions, typically through a cap on the abandonment rate, a requirement to play an informative message rather than dead air, and rules about how quickly the call must be connected. The specifics vary by country, and by the type of calling you are doing.
Which mode should you choose?
- Preview
- Use where the call is worth preparing for: high-value B2B, complex accounts, sensitive collections, anything where opening with the wrong context costs you the conversation.
- Progressive
- The reasonable default for most operations. It removes dialing and waiting from the agent's job without introducing abandoned calls, which keeps the compliance position simple.
- Predictive
- Justified at scale — large lists, low connect rates, and enough concurrent agents for the statistics to work. It needs monitoring and answering-machine detection to be worth the added risk.
Predictive pacing only pays off with a sufficiently large agent pool. With a handful of agents the prediction has too little to work with, and you get abandoned calls without meaningfully improving utilisation.
What else affects outbound performance?
- Retry rules — how many attempts, how far apart, and at what times of day
- Local calling windows — respecting the customer's own timezone, not the office's
- Do-not-call and consent checks performed before the dial, not after
- Answering-machine detection, which needs validating against real answering machines before being trusted
- List quality and lead scoring — dialing order usually matters more than dialing speed
- Callback handling, so committed times are actually honoured
In most operations the highest-leverage change is not the dialing mode. It is calling better-ordered lists at better times, with fewer wasted attempts on numbers that should never have been dialed.
Frequently asked questions
- Is predictive dialing legal?
- It is regulated rather than prohibited in most markets, commonly through limits on abandoned-call rates, requirements about what a customer hears if no agent is available, and restrictions on calling times. Confirm the specific rules for the jurisdictions you call into before enabling predictive pacing.
- What is the difference between progressive and power dialing?
- The terms are used loosely and often interchangeably. Progressive normally means one call per available agent; power dialing sometimes means the same thing and sometimes means a fixed multiple of calls per agent, which behaves more like predictive. Ask what the ratio actually is rather than relying on the label.
- Does dialing mode affect answer rates?
- Not directly — but pacing does affect abandonment, and repeatedly abandoning calls to the same numbers damages how those calls are received over time. Calling behaviour influences reputation, which influences answer rates.
- Can you mix modes across campaigns?
- Yes, and most operations should. Preview for a small high-value list and progressive for volume work is a common combination, with pacing configured per campaign rather than globally.