Main menu About this Site Table of Contents. Practices of Science: Precision vs. Precision and accuracy are two ways that scientists think about error.
Accuracy refers to how close a measurement is to the true or accepted value. Precision refers to how close measurements of the same item are to each other.
Precision is independent of accuracy. That means it is possible to be very precise but not very accurate, and it is also possible to be accurate without being precise. The best quality scientific observations are both accurate and precise. A classic way of demonstrating the difference between precision and accuracy is with a dartboard. Think of the bulls-eye center of a dartboard as the true value. The closer darts land to the bulls-eye, the more accurate they are.
Question Set:. An oceanographer needs to go out in a boat to collect an important temperature and salinity data logger that is attached to an underwater buoy. How does each of the following situations illustrate the differences between precision and accuracy? If you weigh yourself on a scale three times and each time the number is different, yet it's close to your true weight, the scale is accurate.
Yet it might be better to use a scale that is precise, even if it is not accurate. In this case, all the measurements would be very close to each other and "off" from the true value by about the same amount.
This is a common issue with scales, which often have a "tare" button to zero them. While scales and balances might allow you to tare or make an adjustment to make measurements both accurate and precise, many instruments require calibration. A good example is a thermometer. Thermometers often read more reliably within a certain range and give increasingly inaccurate but not necessarily imprecise values outside that range. To calibrate an instrument, record how far off its measurements are from known or true values.
Keep a record of the calibration to ensure proper readings. Many pieces of equipment require periodic calibration to ensure accurate and precise readings. Accuracy and precision are only two important concepts used in scientific measurements. Two other important skills to master are significant figures and scientific notation. Scientists use percent error as one method of describing how accurate and precise a value is. It's a simple and useful calculation.
Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads.
Apply market research to generate audience insights. Measure content performance. Develop and improve products. This particular resource used the following sources:. Skip to main content. Introduction to Chemistry. Search for:. Accuracy, Precision, and Error. Learning Objective Describe the difference between accuracy and precision, and identify sources of error in measurement. Precision expresses the degree of reproducibility or agreement between repeated measurements.
The more measurements you make and the better the precision, the smaller the error will be. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet. Licenses and Attributions.
0コメント