UNICOM Intelligence Interviewer uses the IBM SPSS Dialer hardware to enable power dialing and predictive dialling on telephone interviewing projects.

IBM SPSS Dialer is a dedicated hardware system that interfaces between ISDN (which provides the trunk lines) and the extensions used by the interviewers. It dials a series of specified numbers on the trunk lines and, when a call is answered, connects that trunk to a suitable interviewer on an extension. It also handles audio monitoring of interviews and the recording of audio files.

Each interviewer is connected to one extension on the dialer. Dialer extensions are divided into groups, where each group of extensions handles a specific project.

The interviewer session engine communicates with IBM SPSS Dialer using the QSAMP dialer interface component and the QSampLib type library, as shown below. This implements a TCP/IP connection between UNICOM Intelligence Interviewer and the dialer using the QSAMP protocol. See QSAMP Dialer Interface component for more information.

The Interviewer Session Engine uses a project's DialingProvider property to determine which dialing sample management provider to use. If this property is not set, dialing is disabled for that project. The Interviewer Session Engine then uses the project's SampleManagementProvider property to determine which sample management provider to use.

The dialer interface component writes logging information to the IVW*.tmp files. This includes messages when each sample record is dialed, when a connection is made (in this case the call and the sample record are passed to the interviewer), when a call is hung up, and when the dialer is unable to make a call. Any calls that do not result in a connection return the sample record to the sample management system.