mehavey, could you reference my post next time so i get an alert? i didn't see this right away.
denton, we have duelled on this topic many times in the past. one of your examples helps me remember the main difference between accuracy and precision. you cited an example of speed and velocity. you likened speed (precision)to a tensor and velocity (accuracy) to a vector. thanks for that. precision is a mathematical idea and accuracy is a physical idea because precision does not have a vector.
mehavey, i said "about the mean value", not "from the mean value". "from" indicates distance, or dispersion. "about" indicates nearness.
https://www.merriam-webster.com/dictionary/about
so, "spread from the mean" (a vectored amount) is accuracy. therefore, both of your illustrations have the same precision. and the right illustration is, obviously, the more accurate.
i'm not trying to be an ass about this. i'm trying to get people to understand that we are discussing a group of holes in paper caused by a person shooting a firearm (the results of an action), not evaluating widgets on a manufacturing production line. a subtle difference when discussing accuracy and precision, but a difference none the less.
murf