Day 1    Today we will illustrate the concepts of accuracy and precision by examining various distributions of darts on a target board.  We will introduce the idea of “error analysis” and relate this concept to the process of measurements made on a distribution of darts.

Activity:

Step One:  Write your name, today’s date, and the heading “Measurement Day 1” on a piece of paper.

Step Two:  Using the Concept Map Link above, navigate back to the Main Page for measurement, and then click on Vocabulary.  Carefully read and write down the definition for accuracy and the definition for precision on your paper.  Then return to this page by using the Measurement link at the top of the Vocabulary page, then clicking on Day 1 on the Measurement Page.

Step Three:  There are four pictures of dartboards at the top of this page.  Examine the picture in the lower left corner.  Using a compass, carefully draw a 6-cm diameter circle on your paper. Using small circles, indicate the location of the tips of the darts within your larger circle.  Label this circle, “Both acccurate and precise”, then using the definitions that you wrote down on your paper, write several complete sentences to explain why this picture represents both accuracy and precision.

Step Four:  Repeat what you did in Step Three for each of the other three remaining pictures.  You will have to decide what label you are going to use for these pictures.  Possibilities include: “Accurate, but not precise”, “Shows some precision, but not accuracy,” or “Shows neither accuracy nor precision.”

Homework assignment #1: 

Part One:  Demonstrate your understanding of accuracy and precision by drawing your own appropriate distributions of darts for the following cases, using the method described in Step 3 above.  (Please follow the directions!)

Neither accurate nor precise

Precise but not accurate

Accurate but not precise

Both accurate and precise

Explain in words why you made each drawing the way it is.

Part Two:  Label each of the sets of data below as accurate, precise, inaccurate, or imprecise, as appropriate.  In each case the true value of the measurement is 13.23

1. (a) 12.32, 14.22, 13.28
   

2. (b)  15.25, 15.23, 15.27
   

3. (c)13.24,13.22, 13.23
   

All work for Day 1 of Measurement is due no later than the start of Day 2.  Remember, late work is not accepted.  Please Put your finished work in the appropriate Homework Box or Basket as indicated by your instructor.

You Have Now Completed Day 1 of Measurement