Session 1, Part B:
Data Measurement and Variation

In This Part: Asking Questions and Collecting Data | How Long Is a Minute? | Variables

Problem B6

How well can people judge the time it takes for a minute to pass?

Use the following Interactive Activity to collect data on this question yourself, and try this experiment with a few friends.

 • Did each person estimate the same amount of time? • If not, what do you think accounts for this variation?

For a non-interactive version of this activity, use a stopwatch. Have two or more subjects engage in a conversation, and ask one of them to let you know when he or she thinks a minute has passed. Record how much time actually passed. Repeat this several times with the same or different subjects.

Problem B7

How many raisins are in a half-ounce box of raisins?

We counted the number of raisins in 17 half-ounce boxes:

Number of Raisins in a Half-Ounce Box

 29 27 27 28 31 26 28 28 30 29 26 27 29 29 25 28 28

 a. The 17 counts are not all the same. What do you think accounts for this variation? b. Some of the 17 counts are the same. Why do you think this is?

Problem B8

Should nuclear power be developed as an energy source?

Twenty-five people completed the following questionnaire:

 Question 1:Are you concerned about future accidents at nuclear reactors?

Yes

No

 Question 2:Is the growing amount of radioactive waste from nuclear reactors posing problems for the future?

Yes

No

 Question 3:Do you think we ought to make a more thorough examination of safe energy supplies?

Yes

No

 Question 4:Should we seek to reduce the number of nuclear power stations?

Yes

No

The responses were as follows:

Person

 Question 1 2 3 4

1

No

Yes

Yes

Yes

2

No

Yes

Yes

No

3

No

Yes

No

No

4

Yes

Yes

Yes

No

5

No

Yes

Yes

No

6

Yes

Yes

Yes

Yes

7

No

Yes

Yes

No

8

Yes

Yes

Yes

Yes

9

Yes

Yes

Yes

Yes

10

Yes

Yes

Yes

Yes

11

Yes

Yes

Yes

Yes

12

No

Yes

Yes

No

Person

 Question 1 2 3 4

13

No

Yes

Yes

No

14

Yes

Yes

Yes

No

15

Yes

Yes

Yes

Yes

16

Yes

Yes

Yes

Yes

17

Yes

Yes

Yes

Yes

18

Yes

Yes

Yes

Yes

19

Yes

Yes

Yes

Yes

20

Yes

Yes

Yes

Yes

21

Yes

Yes

Yes

No

22

No

Yes

Yes

Yes

23

Yes

Yes

Yes

Yes

24

No

Yes

Yes

Yes

25

No

Yes

Yes

No

 a. For Questions 1, 3, and 4, there are differences in the 25 responses to each question. What are the sources of this variation? b. For Question 2, there was no variation. Why? Would you expect the same results from another sample of 25 people? c. Take a closer look at this questionnare. How are the questions posed, and how might that influence responses?

 The raisin activity is adapted from Investigations in Number, Data, and Space, Grade 4. Copyright 1998 by Dale Seymour. Used with permission of Pearson Education, Inc.
 Session 1: Index | Notes | Solutions | Video