Libre
Member
I'm fascinated by this topic.
The word metrology refers to the science of measurements. I was first introduced to some of the concepts of metrology when I studied experimental psychology, then later, as a mechanical designer and configuration manager for an aerospace corporation.
Some of the qualities of an instrument are:
accuracy, precision, reliability, traceability, and validity.
They are all different.
I think that an understanding of these qualities, and their subtle differences, improves one's thinking, and improves the quality of one's assumptions in every day living.
I don't assume the general population is fascinated by metrology, as I am, but I'm fascinated by a great deal that most of the rest of the world seems indifferent to.
An example of an instrument that is reliable and precise, but inaccurate: A digital clock that reads down to the second but is always exactly 5 minutes fast.
An example of an instrument that is accurate and reliable but has low precision: A yard stick with engraved divisions at 1 inch intervals.
An example of an instrument that is accurate, precise, and reliable, but with low validity: A scale for weighing people that would determine their height from their weight.
An unreliable instrument: a scale that reads up to 100lbs and has a margin of error of +/- 5 lbs.
I love this stuff.
The word metrology refers to the science of measurements. I was first introduced to some of the concepts of metrology when I studied experimental psychology, then later, as a mechanical designer and configuration manager for an aerospace corporation.
Some of the qualities of an instrument are:
accuracy, precision, reliability, traceability, and validity.
They are all different.
I think that an understanding of these qualities, and their subtle differences, improves one's thinking, and improves the quality of one's assumptions in every day living.
I don't assume the general population is fascinated by metrology, as I am, but I'm fascinated by a great deal that most of the rest of the world seems indifferent to.
An example of an instrument that is reliable and precise, but inaccurate: A digital clock that reads down to the second but is always exactly 5 minutes fast.
An example of an instrument that is accurate and reliable but has low precision: A yard stick with engraved divisions at 1 inch intervals.
An example of an instrument that is accurate, precise, and reliable, but with low validity: A scale for weighing people that would determine their height from their weight.
An unreliable instrument: a scale that reads up to 100lbs and has a margin of error of +/- 5 lbs.
I love this stuff.