You get only one shot at making a good first impression. In an Interactive Voice Response system (IVR), such an impression is formed by callers and conveyed by Voice User Interface (VUI) designers with the application's opening prompt.

When writing your system's opening prompt, keep the following three basic VUI guidelines in mind – be brief, be concise and be polite.

Be brief - Belabored, verbose opening prompts confirm the worst stereotype of the dumb, overbearing IVR system.

Be concise -Each word in your opening prompt needs to be absolutely indispensable. If you can get rid of a word without losing meaning or effectiveness, do it.

Be polite - A system that’s respectful of callers is a system that’s attentive to caller needs and, therefore, a system that will help callers successfully accomplish their task.

Following are 10 tips that can help you craft an effective opening prompt.

1. Drop "Welcome to..."
Simply have your application announce your company's name, preceded or followed by an audio icon, and then followed by your company's tag line.

2. Drop "Thank you for calling..."
Set your application apart with the simple opening described above and save two seconds of prompt time.

3. Use an audio icon
An audio icon is not only an effective way of signaling to callers they are interacting with an automated system, but also a good way of communicating to callers that the system has been designed and crafted with care. The implication is the company cares about its customers.

4. Have the system refer to itself as "I"
Studies have shown callers like to have the system refer to itself with the personal "I" rather than the impersonal "system."

5. Drop "You can interrupt me at any time"
Callers simply do not register the instruction, especially when placed at the opening prompt.

6. Drop "For English…"
If your application starts off speaking in English, have it pause 1.5 or 2.0 seconds after the language instructions for different languages have completed and then proceed with the rest of the prompt in English.

7. Establish that callers can use speech
If your application is speech enabled, make sure your opening prompt conveys that upfront. Have the first interaction ask callers to answer a yes/no question by explicitly saying, "you can say 'yes' or 'no.'"

8. Don't mention the Web site upfront
Chances are good people calling you not only already know you have a Web site, but they found your phone number on the Web site. Don't risk insulting your callers' intelligence or making them feel you really don't want to interact with them by phone. If you mention the Web site, try to mention a specific page where they can find help and mention it at moments where you have determined the help they are seeking could be obtained via the Web. A good place to mention the Web site is at the closing of the call.

9. Postpone the call-recording disclaimer
If you are recording interactions between callers and live agents only, not the automated part of calls, then delay the obligatory message, "this call may be recorded for quality assurance purposes" to just before the call is being transferred to a live agent. Such disclaimers not only lengthen the opening prompt, but have come to be taken as a cue that the caller is about to be transferred to a live agent and may needlessly frustrate callers when no such transfer follows.

10. Turn off your "barge in"
If you are speech-enabling your voice site, make sure you turn the "barge-in" on your application off. Background noise of a caller's inadvertent speech utterance may trip the opening prompt, resulting in a no-match in the first few seconds of the interaction. The only time you should turn barge-in on at the opening prompt is if the majority of your callers are frequent callers who know exactly what to say or push and may (and will) be irritated if they are forced to listen to the opening prompt, no matter how brief.

By Dr. Ahmed Bouzid, who heads the Partnerships and Strategic Alliances program at Angel.com. He has over 15 years’ experience in the Speech and Natural Language Processing industry and has written extensively on Voice User Interface design and Natural Language Processing.