Preconceived notions very commonly get in your way with Root Cause Analysis. Here is a perfect example. In this picture you can plainly see that the people on the left are taller right? Look again... Maybe we did not have all of the facts at first. It seems that in the video there is more going on than we thought. Our notions of what a room is and how it is typically shaped do not hold true in this case. This irregularity, led us to a poor understanding of the situation. Many times we go after issues with our personal opinion of the problem and the solution predetermined and it blinds us to the truth of the matter. All the data must support the conclusion not just the parts that you like. I have seen these preconceived notions derail investigations time after time and, it is one of the reasons that I suggest not using subject matter experts as RCA facilitators in this blog. Check out this post for 5 ways to help prevent jumping to conclusions. Then let us know what thoughts and ideas you have for avoiding this common problem by listing them in the comments section below.