Metrology Monday! #79 Beginning a Discussion on Conformity Assessment, Decision Rules and Measurement Decision Risk

At the NCSLI Conference this year, there were quite a few presentations on Conformity Assessment, Decision Rules, and Measurement Decision Risk.? I did not catch all of them, but I saw some good talks and I saw some not-so-good talks.? I am amazed that there is so much misunderstanding and incorrect information out there.? There are some fantastic papers in the public realm on this subject, but I think that the challenge may be that the language and discussion is not at a level that is easily understood by all.? This is a very challenging subject, and the well-educated presenters can easily get lured into the very complex math that is required to master this subject.? In the past, when I taught this subject, I think I found myself getting drawn into the same trap of focusing on the math and not on the concepts.?

When physics is taught, we focus first on the concepts.? Many of the same concepts about acceleration, gravity and motion are the same in grade school as it is in college, the only difference is that by the time we are in college, the mathematics are more sophisticated.? I am going to start a discussion on this subject, and I am going to do my best to focus on the concepts and keep them at a level where not only can we all understand them, but perhaps we can share them with our customers so that they can learn as well.

So let’s start that the beginning:

What is a measurement?

Measurement is the process of quantifying our experiences in the world.? Measurement is a part of the human experience; it is what separates us from other lifeforms.? I think that part of the challenge with this concept is that we make dozens and perhaps hundreds of measurements every day, perhaps so many that we are no longer conscious of the process.? We make measurements when we take medicine.? We measure when we cook.? We measure when we play sports (time, yardage).? We measure when we purchase things such as food or fuel.

Why do we make measurements?

When I ask metrologists this question, I often see them struggle with an answer, maybe because it has become an unconscious thought to us.? After a moment they will come up with good answers.? I have thought about this quite a bit myself.? The best answer that I can come up with is, we make measurements in order to gain knowledge to make decisions.? The knowledge that we want to attain may be very simple, like “how far away is it?”, “How fast am I going?” and “How hot is that stove?”? once we have the knowledge, we can use it to make a decision, such as “I will not touch that stove, it can injure me.”?

Although this audience is principally interested in calibration, this topic goes well past the calibration field.? The information that we will be covering can apply to any measurement that we make, because the heart of this discussion is measurement quality, the process of gaining the highest quality of measurement information so that we can make the best decisions. #MetrologyMonday #FlukeMetrology??