Telephone interviews could be classified into CATI (computer-assisted telephone interviews when numbers are dialed automatically, operators fill in the questionnaire on the computer and the interview is recorded) and regular telephone interviews (standard not computer-assisted telephone conversations).

Telephone interview strengths:

• In many cases this is the most cost- and time-effective method
• It allows for a vast geographical coverage from a single base
• This method is best suited for reaching people not available for a face-to-face interview (for example, top managers and highly skilled professionals, etc.)

Telephone interview weaknesses:

• It is not always feasible to run proper screening (for example, age check)
• The interview is limited to 20-25 minutes.