Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Accuracy vs Precision vs Resolution issues #494

Open
maxschommer opened this issue May 4, 2024 · 4 comments
Open

Accuracy vs Precision vs Resolution issues #494

maxschommer opened this issue May 4, 2024 · 4 comments

Comments

@maxschommer
Copy link

Here it is said that the narrowly distributed temperature readings represent a more accurate thermometer, when I think it is intended to mean a more precise one. The book previously established that we will assume no systemic bias, or inaccuracy. This occurs in other places before this, and perhaps in future sections of the book. If I track down more instances of this I'll add them as comments to this issue.

"If we think back to the thermometer, we can consider these three curves as representing the readings from three different thermometers. The curve for $\\sigma^2=0.2^2$ represents a very accurate thermometer, and curve for $\\sigma^2=1^2$ represents a fairly inaccurate one. Note the very powerful property the Gaussian distribution affords us — we can entirely represent both the reading and the error of a thermometer with only two numbers — the mean and the variance.\n",

@maxschommer
Copy link
Author

"What does this curve *mean*? Assume we have a thermometer which reads 22°C. No thermometer is perfectly accurate, and so we expect that each reading will be slightly off the actual value. However, a theorem called [*Central Limit Theorem*](https://en.wikipedia.org/wiki/Central_limit_theorem) states that if we make many measurements that the measurements will be normally distributed. When we look at this chart we can see it is proportional to the probability of the thermometer reading a particular value given the actual temperature of 22°C. \n",

Here is another instance. I think in context that "precise" is meant instead of "accurate". While it is a true statement that no thermometer is perfectly accurate, the variance from reading to reading that is being alluded to here is a precision issue, not necessarily an accuracy one.

@maxschommer maxschommer changed the title Accuracy vs Precision issues Accuracy vs Precision vs Resolution issues May 4, 2024
@maxschommer
Copy link
Author

Here "precision" is used when I think "resolution" should be used. "precision" is meant to convey how tightly together readings are clustered, where "resolution" is the minimum delta that a sensor can display.

"In practice our sensors do not have infinite precision, so a reading of 22°C implies a range, such as 22 $\\pm$ 0.1°C, and we can compute the probability of that range by integrating from 21.9 to 22.1.\n",

@maxschommer
Copy link
Author

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

1 participant