PART 3

In Part 3, you will design and conduct two different tests to compare the magnetic strength of the strong magnet and the weak magnet that you identified in Part 2. You will record your results in Table 4 on page 14.

• In the top row of Table 4 (columns 2 and 3), write down the numbers on the bars you identified as the strong magnet and the weak magnet in the spaces provided. Use the final identifications in Table 3 on page 11.

Think about how you can use the materials in your kit to test these magnets and demonstrate that the strong magnet is stronger than the weak magnet. You may use any of the materials in your kit.

• Now conduct two different tests to compare the magnetic strength of the strong magnet and the weak magnet.
• In Table 4, describe the materials and procedures you used. Record all measurements you made, including numbers and units in columns 2 and 3 under Results/Data.
• Do not forget to write in the number of the metal bar that you think is the strong magnet and number of the magnetic bar you think is the
  weak magnet.

Sample correct student response:

TABLE 4: COMPARING THE STRONG AND WEAK MAGNETS

This item was scored in three parts:

Part A: Identification of strong and weak magnets
Part B: Test 1 procedure and results
Part C: Test 2 procedure and results

Part A:

Complete:
Student response enters correct choices for both strong and weak magnets. Bar number 2 is a strong magnet; bar number 3 is a weak magnet.

Partial:
Student response enters correct choice for the strong magnet or the weak magnet.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Part B:

Complete:
Student response provides a complete procedure for Test 1, such as testing how many steel disks the magnets can hold. The procedure includes the materials to use and the steps to follow. Response provides numerical data.

Partial:
Student response provides a complete procedure for Test 1. The response provides only non-numerical data or inconclusive results.

OR

Student response provides a partial procedure for Test 1. Response provides numerical or non-numerical data, conclusive or inconclusive results.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

 
Part C:

Complete:
Student response provides a complete procedure for Test 2 that is different from Test 1, such as determining the smallest distance that a magnet can be placed near the unlike pole of the test magnet before one of the bars begins to be moved and pulled toward the other bar. The procedure includes the materials to use and the steps to follow. Response provides numerical data.

Partial:
Student response provides a complete procedure for Test 2 that is different from Test 1.
The response provides only non-numerical data or inconclusive results.

OR

Student response provides a partial procedure for Test 2 that is different from Test 1. Response provides numerical or non-numerical data, conclusive or inconclusive results.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Composite Score:

This item received two scores, one score for Part A, and a composite score for Parts B and C. For Parts B and C, student response received one of four possible composite scores (Complete, Essential, Partial, Unsatisfactory/Incorrect) based on the student's combined performance on these parts. For example, a student response Complete for Part B, and Unsatisfactory/Incorrect for Part C received a composite score of Essential.

Which metal bar is the strong magnet?

Sample correct student response:

Which metal bar is the weak magnet?

Sample correct student response:

Explain how your data and observations showed that the strong magnet is stronger than the weak magnet.

Sample correct student response:

Score and Description

This item was scored in two parts.

Part A: Identification of the strong and weak magnets

Part B: Evidence for identification

Part A:

Complete:
Student response selects correct choice for both the strong and weak magnets. Strong magnet is (B) Bar 2; weak magnet is (C) Bar 3. Multiple selections for either strong or weak magnet do not receive credit.

Partial:
Student response selects correct choice for the strong magnet (B) Bar 2, or selects correct choice for the weak magnet (C) Bar 3.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Part B:

Complete:
Student response provides a valid explanation of how the data and observations in Table 4 showed that the strong magnet is stronger than the weak magnet for at least one of the tests shown in Table 4. Explanations are based on numerical results.

Partial:
Student response provides a valid explanation of how the data and observations in Table 4 showed that the strong magnet is stronger than the weak magnet for one or both of the tests shown in Table 4. Explanations are based on non-numerical results or incorrectly cited numerical results.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Composite Score:

Student response received one of four possible composite scores (Complete, Essential, Partial, Unsatisfactory/Incorrect) based on the student's combined performance on Parts A and B of the item. For example, a student response Partial for Part A and Unsatisfactory/Incorrect for Part B received a composite score of Partial.

Cleaning Up

When you have finished this task, put the steel washers in the small plastic bag and the metal bars and test magnet back in their box. Then put everything back into the large plastic bag.

SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Science Assessment.