2. Accuracy and Precision

3.  Precision reflects the reproducibility of a given type of measurements (same answer) (same answer)  Accuracy reflects how close a group of measurements are to an accepted value (right answer) (right answer)

4. The dart throws reflect measurements that are:  precise  not accurate

5. The dart throws reflect measurements that are:  accurate  precise

6. This dart board reflects measurements that are:  not accurate  not precise

7. Student A 7.39.48.3 Student B 8.28.18.0 Student C 8.88.68.9 Which student had the best lab technique? What could you say about Student B’s lab technique? What is evident about Student A’s lab technique? Actual density of copper = 8.94 g/cm 3 Not accurate Not precise Not accurate Precise Accurate Precise Student C Makes the same mistake over and over Sloppy in his measurements

8. Density Data Collected by Three Different Students Student AStudent BStudent C Trial 11.54 g/cm 3 1.40 g/cm 3 1.70 g/cm 3 Trial 21.60 g/cm 3 1.68 g/cm 3 1.69 g/cm 3 Trial 31.57 g/cm 3 1.45 g/cm 3 1.71 g/cm 3 Average1.57 g/cm 3 1.51 g/cm 3 1.70 g/cm 3 Actual density = 1.59 g/cm 3

9. Which lab group measured the volume of the liquid with the most precision?

10. The table shows four mass readings of one object as measured by four different balances. Which balance produced the most precise measurements? actual mass = 25.00 g

11. These data were gathered by four groups of students. Each group performed four trials to test the acceleration rate of a toy car. Which group had the most precise data?