How many of the analytical chemists reading this will identify with the following scenario? A customer gives you a sample with a contaminant and asks you to identify the material. Your customer provides a very logical dissertation on what the material is likely to be. With that bias firmly entrenched in your mind, you proceed with the analysis, fully expecting to find what your customer said you should. However, during the course of your analysis, you discover that the contaminant is something completely different than expected. Now you are presented with the dilemma of facing that customer to explain the “unexpected” result. You are immediately put on the defensive by being accused of not having properly calibrated instruments or you have obviously contaminated the sample with something else during sample preparation, etc. These situations occur in laboratories all over the world.