Chapter 1 Measurements

1. Chapter 1Measurements Accuracy and Precision Timberlake LecturePLUS

2. Accuracy How close a measurement is to the actual or true value good accuracy true value poor accuracy true value Timberlake LecturePLUS

3. Precision How well several measurements agree with each other good precision poor precision Timberlake LecturePLUS

4. Accuracy and Precision What can you say about the accuracy and precision in each of the following: Good precision, poor accuracy Good precision, good accuracy Timberlake LecturePLUS

5. In your new job, you are to make the pizzas the size shown above. Your first four pizzas are shown below. What can you say about the accuracy and precision of your pizzas? Timberlake LecturePLUS

6. The next four pizzas. What can you say about the accuracy and precision of the next four pizzas? Timberlake LecturePLUS

7. Accuracy is improving. The two pizzas in the center show good accuracy. However, the precision is poor. Timberlake LecturePLUS

8. Pizza Precision You have very good precision, but poor accuracy. I think the customers will want the pizzas made larger. Timberlake LecturePLUS

9. Learning Check AP1 Match the following terms 1) Accuracy 2) Precision ___ How close a measurement is to the true value. ___ How close several measurements are to each other. Can you have data that are precise, but not accurate? Why or why not? Timberlake LecturePLUS

10. Solution AP1 Match the following terms 1) Accuracy 2) Precision _1_ Is how close a measurement is to the true value. _2_ Is how close several measurements are to each other. Yes. Data can be precise, but not come close to the true value. Timberlake LecturePLUS

11. Learning Check AP2 How will each of the following affect accuracy and precision? 1. A meter stick that is missing the first centimeter. 2. A scale that has a zero point that is really five pounds above zero. Timberlake LecturePLUS

12. Solution AP2 How will each of the following affect accuracy and precision? 1. The shortened meter stick will produce measurements that have poor accuracy, but good precision is possible. 2. The poorly calibrated scale will give a weight that is not accurate, but good precision is possible. Timberlake LecturePLUS

13. Learning Check AP3 True(1) or false (2). Measurements can have poor accuracy and poor precision good accuracy and poor precision poor accuracy and good precision good accuracy and good precision Timberlake LecturePLUS

14. Learning Check AP3 True(1) or false (2). Measurements can have poor accuracy and poor precision good accuracy and poor precision poor accuracy and good precision good accuracy and good precision 1 2 1 1 Timberlake LecturePLUS