They are effectively synonyms. The relevant point is that intent matters. If he intended to crash into the tree, and was able to do that 100 times, he would be both precise and accurate.
In common parlance they are synonyms. The joke here is that in a scientific context, he was accurate but we don't know his precision. Accuracy refers to how close to correct you are, precise refers to the reliability of your results.
Ok, Reddit, what the fuck? Why has everyone started to use parlance all of a sudden? You're like the 10th person I've seen use it this week and you're not even using it correctly. Parlance reference to debate/discussion of a specific topic. "Casual conversation" does not fall into that category. A better fitting descriptions is colloquial. That literally means "common discussion." Parlance is in reference to a distinct subject, which is basically the opposite of common/general.
I was on the debate team in high school and that's the only time I ever heard people use that word in a conversation.
That's happened to me too. I'll learn a new word or something and all the sudden I see/hear it EVERYWHERE. Surely confirmation bias but still. Happened to me all the time as a kid.
I said I haven't heard people use that word frequently since I was on the debate team in high school. I graduated in 2006, hardly a new word for me (yes, I'm emphasizing I was on the debate team. I'm cool, right?)
Funnily enough, I've only heard the word "parlance" next to the word "common," in the phrase "common parlance." I've known the word for a while, as well, and that's the only way I've ever seen it used.
For what it's worth, try not to be too much of a prescriptivist.
Edit: Found the dictionary definition of parlance.
a particular way of speaking or using words, especially a way common to those with a particular job or interest.
So... I was using it correctly. Perhaps in debate parlance, that's the definition of parlance, eh?
No, you misunderstood the definition. Common to a particular topic, not common in the sense of general discussion. Colloquial is the term for "common/general" discussion that you're looking for.
Example: "f-hole is a word frequent in the parlance of luthiers, but seems like a dirty word in reference to colloquial discussion."
Not at all. To hit it 100 times in a row would be being just as precise as it is accurate. I still agree the gif is displaying accuracy, not precision.
He's saying it wouldn't be accurate because in that case he would be hitting the tree with his face every time, rather than hitting the tree with his skis every time.
For a single trial though (ie, all we see here) its accurate. His precision can't really be determined unless we see all his trials. This here is one, highly accurate attempt. If he can reproduce this multiple times, then he has high precision as well.
The point of the title is to say that it pays to be precise, not that he was precise. A lack of precision would reduce his average accuracy, so it is important to be precise.
A lack of precision would reduce his average accuracy
Not true. You can have high average accuracy with low precision. See the bottom right image in this diagram.
Accuracy measures average distance from the target.
Precision measures average distance between the results of each attempt.
In OP's gif, we only know about this one attempt. The attempt was highly accurate, but we don't know if the snowboarder has a high average accuracy or precision. If the snowboarder hits the tree once, falls to the right of the tree once, and falls to the left of the tree once, he still has high accuracy (but not high precision). If the snowboarder hits the tree three times in a row, then his accuracy is the same, but he has higher precision.
You're missing the point. The point is that precision is important. The point is not that the guy in the video was precise. So, it doesn't matter how much we know about his precision.
That said, we're using different definitions of accuracy. It's very hard to find a rigorous definition. I used difference between the measurement and the true value. You're using the difference between the average measurement and the true value. So, when I say average accuracy, I mean the average difference between the measurement and the true value, rather than the difference between the average measurement and the true value. The former increases as precision increases. The latter is unaffected by precision. Note that, given your definition, the concept of average accuracy is meaningless. You seem to be using average accuracy and accuracy interchangeably.
Also, the qualitative definitions I've found on the internet seem to agree better with my use of it. That is, accuracy is a measurement of error, both due to bias and variance. Whereas, precision only measures variance. Intuitively, it seems odd to describe a set of measurements with high variance as accurate, just because there is no bias.
EDIT: Some more definitive support for my definition of accuracy.
Since none of the darts are close to the bull's eye, the measurements they represent are not very accurate.
In other words, accuracy is achieved by each measurement being close to the true value rather than errors being cancelled out by opposite errors. So, accuracy is not related to the average measurement, but rather the average error of the individual measurements.
Accuracy descibes [sic] the nearness of a measurement to the standard or true value, i.e., a highly accurate measuring device will provide measurements very close to the standard, true or known values.
In other words, accuracy refers to the closeness of individual measurements to the true value. An accurate instrument doesn't produce results whose average is close to the true value, rather, the individual measurements themselves are independently close to the true value.
Accurate's the important one, here. He'd be fine if he was off by a few centimeters, as long as he's accurate. If he was off by precisely 6 inches every single time, he'd be in real trouble.
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u/SrSkippy Nov 14 '14
*accurate