'Interview' may be defined as conversing with a person in order to obtain information. 'Interrogation' is a questioning with the force of an emphatic affirmation or denial. In general, the subject of an interview is more likely to be friendly, while the subject to be interrogated is hostile. In both situations, the investigator must take into account human factors such as reluctance to talk, perception, memory, prejudice, and accuracy of information obtained. The investigator's attitude is often the deciding factor between success and failure. Sometimes, witnesses refuse to give their names or telephone numbers. Interviewing different age groups must be considered; surprisingly, small children can often provide accurate information. It is essential that the investigator have a close working relationship with firemen. Main topics of discussion in an interview with a fireman include date and time of the fire alarm, method of receiving the alarm, conditions observed enroute, location of the fire, kind and color of smoke, spread of fire, and the condition of fire protection systems. The investigator must remember that the law will assist him in dealing with an uncooperative witness. A six-entry bibliography is provided.