Objective

Uncertainty abounds us in every aspect of life, what we strive to achieve is to reduce uncertainty yet it can all but be eliminated. At best we try and reduce uncertainty to give us the highest level of confidence possible to help achieve a desired result. The higher the level of confidence we have by reducing the level of uncertainty, the greater the probability we have to predict possible outcomes.

As mentioned in the outset, uncertainty plays into every aspect of life yet often we don't identify or analyze it. For example, think of a time when someone asked you a question and after you responded they asked "are you sure?" You may have responded with "I think so". The "I think so" part of your response is directly related to the level of uncertainty you have with your response and the degree of which is directly related to the level of confidence you had to your response. In this case your confidence in your response is low due to a high uncertainty level. Had you said "absolutely", that would have indicated you have a high level of confidence presumably based on a low level of uncertainty. You might have also said something like "wait let me check something," at that point what you are doing is trying to eliminate some uncertainty in order to increase your confidence to your response.

Among other things, ASTM strives to lower uncertainty and increase confidence by authoring and maintaining standard test methods and practices that help increase the probability to predict a particular repeatable outcome. However, uncertainty is sort of a double headed monster with one head being Objective Uncertainty and the other Subjective Uncertainty. Today we will focus on Objective Uncertainty.

Objective Uncertainty allows you to make knowledge guided predictions but in requires a critical path to reach that point. Part of that path takes us through the ASTM documents and along the way there are procedures referenced to help reduce additional uncertainty. These procedures require tools and apparatus to aid access a particular condition by gathering quantitative data. This data is then evaluated as required to achieve the confidence level required in order to make a proper decision of the results i.e. 68.3% ("one sigma"), 95.4% ("two sigma"), or 99.7% ("three sigma") confidence intervals. These tools and apparatus are affected by uncertainty as well. The degree of uncertainty and confidence depends on both accuracy and precision of the instrument used. The lower the accuracy and precision of an instrument, the greater the measurement uncertainty and therefore a lower confidence level of the objective results.

During this workshop, we will look at three common activities and the devices used to collect data to reduce uncertaintyassociated with Color, Coating Thickness and Viscosity. Of the three, Color is the most recent to emerge from Subjective Uncertainty to Objective Uncertainty. With both Coating thickness and viscosity, the levels of uncertainty are dependent on several factors associated with the particular devices accuracy and precision. To that end we will have a closer examination of Color testing presented by Nick Barnes of Tintometer LTD. In addition to Nick's presentation, there will be a presentation on Coating Thickness Testing from John Fletcher of Elcometer Limited and a presentation on Viscosity from Cliff Schoff of Schoff Associates.