What is the natural temptation for you, a safety professional assigned to be the lead incident investigator, as soon as the assignment is made? "Who was involved? I want to talk with them." Many inexperienced safety professionals jump right into interviews. I suggest that the effectiveness of your interviews will be proportional to your preparation. To improve your chances of revealing the deeper causes of events, you must prepare.
There are times when urgency dictates minimal preparation, but try using as many of the following tips as possible before moving into the actual interview. As you gain experience, you can perform most of the following actions to some degree within one hour.

One of your first activities should be to find out whatever you can about what happened. Try to obtain video and audiotapes, photographs, written statements, and equipment recorder data. You are trying to put a story together using available objective information before overlaying the first-hand accounts. 

You should obtain written procedures or training documents that describe how the particular task that was in progress should happen. If the process or method is not documented, prior to interviewing the involved personnel, talk with knowledgeable people to determine how the activity should be performed. By understanding the right way to do the task, you will be able to recognize during the interview when those involved deviated from the correct method. This knowledge will allow you to probe those critical decision points to identify the deeper reasons why the event occurred. 

From the available data and initial conversations, find out who was involved. Characterize the involved people in one of three ways: directly involved, observers (or witnesses), or background. Directly involved means they were directly involved in the incident or chain of events that led to the incident. Observers are people that actually saw the incident or key decision points along the way. The final grouping is for people knowledgeable of the process or task, supervisors, and others associated with latent causes. To the extent possible, you must interview people directly involved and witnesses within 48 hours of an incident. This urgency is necessary to capture deeper reasons for behavior and decision-making. 

Based on your reconstruction from the evidence, you should have some idea of what happened. Each person you interview played a specific role in the sequence of events. Part of your preparation is to write down the questions you want to ask each person, based on the information you need from that person. 

Several tips are related to the interview setting. You need to make the interviewees feel at ease so that they will be more willing to share deeper reasons for actions. A quiet location, out of sight of normal crew quarters, and not adjacent to management offices usually works best. No matter where the location, some amount of privacy is needed. This requires pre-planning. Arrange the seats around a table, with all participants facing each other. Make sure the room is comfortable. You should always conduct interviews with only one involved person or witness at a time, and limit the number of interviewers to no more than three.
Pulling it all together, you are preparing for a reason. The evidence you collect will tell you what happened. You interview the people involved to find out why things happened. Your interview preparation is meant to give you a foundation for understanding what happened and to gain the most relevant information from those involved by making them comfortable and willing to share their understanding of why things happened.
Like many aspects of incident investigation, interviewing is a performing art that requires practice to become proficient. Try these tips before you conduct your next interview and you should see a difference. ip

Dr. Tyrone Tonkinson, President – Simple Approach, Inc., has more than 20 years of electric utility experience and is a recognized expert in root cause analysis, human performance, and organizational assessment. For more information, visit www.simpleapproachinc.com.

Editor's Note: This article is the first in a two-part series intended to give utility safety professionals tools and tips that they can immediately use to become a more effective interviewer. Look for "Part 2: Contact Time" in the March/April 2007 issue of Incident Prevention.