# What is Accuracy: Definition and 234 Discussions

In a set of measurements, accuracy is closeness of the measurements to a specific value, while precision is the closeness of the measurements to each other.
Accuracy has two definitions:

More commonly, it is a description of systematic errors, a measure of statistical bias; low accuracy causes a difference between a result and a "true" value. ISO calls this trueness.
Alternatively, ISO defines accuracy as describing a combination of both types of observational error above (random and systematic), so high accuracy requires both high precision and high trueness.Precision is a description of random errors, a measure of statistical variability.
In simpler terms, given a set of data points from repeated measurements of the same quantity, the set can be said to be accurate if their average is close to the true value of the quantity being measured, while the set can be said to be precise if the values are close to each other. In the first, more common definition of "accuracy" above, the two concepts are independent of each other, so a particular set of data can be said to be either accurate, or precise, or both, or neither.

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2. ### B Which science communicator do you find to maintain the most accuracy?

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3. ### I Measurement Error Analysis in Gaussian distribution

I am new to statistics and recently learned about ISO guidelines for Accuracy & Precision and Uncertainty & Error. But there are some graphs of probability distribution I found on internet which I am not able to grasp. image Source Q. In this graph(above) if...
4. ### I What is the accuracy of parking spacecraft into Lagrange points?

I often wonder what the accuracy is when dealing with spacecraft and wondered how accurate a craft needs to be positioned into the Lagrange (L1,L2,L3) positions. Are we talking plus or minus 1km/100km/1000km etc. It's just that the system is so vast and what instruments are used to achieve a...
5. ### I Measurement accuracy or variation

I find the values of the fundamental constants here https://physics.nist.gov/cuu/Constants/ In anticipation of the data of 2022, I want to clarify one point. Planck's constant is related by an exact expression to some other fundamental quantities: $$h = \frac{\alpha^2 m_e с^2}{2R_c}\qquad (1)$$...
6. ### How does the accuracy of the clock change when the spring stretches?

A longer pendulum swings slower. So changing the length l of the pendulum changes the period T, which affects the timekeeping accuracy. But the problem is talking about the body on the spring, not the string. So the second formula cannot be applied here directly and I don't know how to progress...
7. ### Why did I get different accuracy for different algorithms?

Here are the codes(not all might be present, take it with grain of salt). https://github.com/prabesh-regmi/Employee-Promotion-Prediction
8. ### A What is the achievable accuracy of neutrino speed measurement?

Is the accuracy of 10^-12 s achievable in measuring a neutrino's speed with current experiments? I have come across a number of papers stating the accuracy is in the order of nanoseconds. This is much lower accuracy than the measured speed of photons. I believe it is due to the difficulties in...
9. ### How to select the required accuracy of an instrument?

If I need to make a measurement to check compliance e.g. measuring component dimensions. How do I know what accuracy is required for the measuring instrument if the tolerance is not specified? For example, during an engine rebuild, the manufacturer specifies the valve stem diameter to be...
10. ### Instrument accuracy and comparison measurements

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11. ### B Accuracy of a smith's crafted metal disc

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13. ### Did your DNA test results change when using a second company to do the test?

Here's the story: I did the 23&Me and it told me that I was about 90% X but then there was among the smaller %ages a Y = French Later, about a year later, I checked it again. The French ancestry had disappeared. There was still 90% X, but now I had a Y = Scandinavia. So, I ran the test again...
14. ### I Accuracy of the Density of States

I'm trying to understand the detailed concept of why the density of states formula is accurate enough to calculate the number of quantum states of an energy level, including degeneracy, within a small energy interval of ##dE##. The discrete energie levels are calculated by E = \frac{h^2 \cdot...
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16. ### B How is a Scientific law/theory's accuracy tested?

How is a Scientific law or theory's accuracy tested? I've searched online about verification of Newton's law but the materials are unhelpful. Many show an experiment that verifies a particular instance of the law and then concludes the law is verified. We all know that there are infinite...
17. ### How Is Error Managed When Measuring the Difference Between Two Values?

Me and some colleagues discussed accuracy of measurements. We didn't agree on how to treat the accuracy if two values are used to find the value, i.e. the difference between two values. Situation (explanation) The weight of a mass m of approximately 5 μg is to be scaled. The scale has an error...
18. ### I Can the LIGO observatories detect (with accuracy) temblors?

With all the earthquakes going on in CA - and that the last one (7.1 mag) was strong enough to possibly trigger a small quake along the LA coast (i.e., as in LouisianA, not Los Angeles) - I was wondering about this. These instruments are so sensitive that they have to pick something up, even in...
19. ### I How Does Reducing Time Intervals Affect Accuracy in Numerical Integration?

In the Tipler & Mosca textbook we are shown how numerical integration (the Euler's method species of it) is done using a spreadsheet program. The authors then go on to say on page 138 that the accuracy of this program can be estimated by first calculating the values for a time interval of 0.5s...
20. ### FiveThirtyEight Assess their Accuracy

This is a podcast and it can be found here. Basically, an interview of Nate Silver, the stat head behind FiveThirtyEight.com. They have made thousands of predictions on politics and sports (which they publish) and consider their competition to be betting sites and other modelers. Nate used to...
21. ### MHB Probability of Order Accuracy from A, C, or Not Accurate

This is a problem I got for a review in probability and statistics The layout of the data is as follows: A B C D Order Accurate- 315 277 234 120 Order not - 34 50 35 18 accurate Like I said previously this is an or...
22. ### Is an Air Gap OK When Micropipetting? Biology Q&A

Used a P100 to pipette 93.6 micro-litres of fluid. There was an air gap in the pipette tip the first time I did it but no air gap the second time. I'm assuming there shouldn't be an air gap but can somebody tell me for sure?
23. ### How does the phase noise of the LO effect IF accuracy?

Hi, I have a roughly 1.1 GHz signal to be downconverted to 100 MHz by mixing it with a 1 GHz local oscillator. I am not sure how to choose the performance of the LO. In particular: let's assume the LO has a jitter of 100 fs rms. At 1 GHz this corresponds to a frequency error of 100 kHz. Does...
24. ### I Accuracy of time dilation measurement *in principle*

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25. ### Compare Precision & Accuracy: Speed of Light Measurements

Homework Statement Two different scientists measured the speed of light four times. Scientist A 3.80*108m/s 3.32*108m/s 3.10*108m/s 3.05*108m/s Average 3.32*108m/s Scientist B 2.90*108m/s 3.10*108m/s 3.24*108m/s 2.95*108m/s Average...
26. ### I Accuracy of the Normal Approximation to Binomial

What is the preferred method of measuring how accurate the normal approximation to the binomial distribution is? I know that the rule of thumb is that the expected number of successes and failures should both be >5 for the approximation to be adequate. But what is a useful definition of...
27. ### I Looking for a cheap digital scale with accuracy <1 g

I currently have a cheap digital scale that will measure, say, from 1 g and beyond to the hundredth place with reasonable accuracy, but for anything less than a gram, it is erratic. For example, when I'm adding 0.15 g of a chemical, sometimes the value will change but often it will not and...
28. ### Length of time needed to measure digital clock accuracy

On a piece of equipment, I purchased new, the digital clock ran slow. The second digital clock that was installed ran slow---it lost approximately 4.1 minutes in one month. Below is what I sent the Service Manager who I understand thinks it is possible to test the newly installed clock...
29. ### Determine acclimation time for metals

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32. ### How Big Must N Be for Stirling's Formula to Achieve 2% Accuracy?

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34. ### I Regarding the precision and accuracy of Atomic mass

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35. ### Use math to prove which lab equipment was precise/accurate?

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36. ### Water level accuracy revisited

Is there any difference in accuracy with using a resivoir vs just the tube? I want to acurately level the torque boxes on my car on jackstands so i can make frame measurements. Thanks
37. ### NASA NASA Eclipse Calculations Accuracy

How accurate do you think NASA's eclipse calculations are? Will that aircraft provide accurate moon trajectory?
38. A

### B Accuracy of moon orbiting earth in how many days and hours

Can anyone tell me accurately. accuracy of moon orbiting Earth in how many days and hours and seconds and if it is multiplied by 14 how much it will be in days. i need accurate answer. Thanks, Ahmed.
39. ### Thin slits and accuracy of Kirchhoff's diffraction formula

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40. ### I Error in declination of linear regression

During a lab exercise we measured different masses of a magnetic material on a scale while changing the strength of the magnetic field it was in. Afterwards we plotted the masses and the fieldstrength hoping to find a linear slope. Then we drew a linear slope by using linear regression and found...
41. ### I How to write measured value with error

During a labexercise we measured a value to be 26.3 mT. The teslameter was said to have an accuracy at +- 0.05%. This means we measured 26.3 +- 0.0132mT. However we are supposed to write a measured value with it's error in the last digit. But the error is smaller than the smallest digit we got...
42. ### What is preventing me from achieving better accuracy for this delay?

I have 2 PERFECT data of the transmitter and receiver. From 2 data, I can calculate the delay estimation: Fs = 8e6; % sample rate ... for i = 1:2 [cc_correlation,lag] = xcorr(signal2(i), signal1); [cc_maximum, cc_time] = max(abs(cc_correlation)); cc_estimation...
43. ### Power supply for multiple devices -- effects on accuracy

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44. ### I On Wave Function Collapse and Accuracy of Energy Measurment

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45. ### I Relativity's "time dilation" or clock accuracy alteration

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46. ### Water level accuracy for squaring a car frame

I have a 1968 Mustang that I bought at auction from my grandfather's estate it is almost completely apart and I want to rebuild it for him has sadly he ran out of time, I have a reproduction manual from 1968 with frame dimensions in it and some of the dimensions car vertical to a datum line. I...
47. ### TDS2004B Oscilloscope Accuracy Determination

Hello, I recently did the Franck-Hertz experiment (a short summary of the experiment can be found here http://inpp.ohiou.edu/~roche/3701_web/man-fh-a3b.pdf). I am currently doing data analysis and am having a hard time determining the accuracy of the oscilloscope, the Tektronix TDS2004B. I am...
48. ### B Why do arrows deviate from the target in archery?

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49. ### B Accuracy in speed of photon - uncertainty?

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50. ### Maximum Theoretical Angular Accuracy of Planer arrays

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