PART 2

You will now test the water samples to check your prediction about which site would be better for the new town.

You have two water samples, one taken from a river close to Town Site A and one from a river close to Town Site B. These are labeled S_A and S_B. In addition, you have a set of four bags containing test strips to test the water quality of your water samples. Each test strip bag contains test strips, instructions for conducting the test, and a reference chart used to interpret the results.

Use the equipment you have been given to perform your water quality tests on the water samples.

Record the pollutant you tested and your measurements for S_A in columns 1 and 2 of Table 1A on page 9.

Record the pollutant you tested and your measurements for S_B in columns 1 and 2 of Table 1B on page 10.

You will add further information to Tables 1A and 1B when you have completed your tests.

Sample complete student response: 

The two tables below are transcriptions of complete students' responses for both questions 2 and 3.

TABLE 1A: Data and Summary Information for S_A

TABLE 1B: Data and Summary Information for S_B 

Part A

Level of Pollutant for Site A

Complete:
Student response lists the four pollutants tested in Table 1A and the correct level for each pollutant. The correct results are shown in the table.

Essential: 
Student response lists at least three pollutants in Table 1A and the correct levels for three pollutants.

Partial: 
Student response lists at least one pollutant in Table 1A and the correct level for the pollutant.

Unsatisfactory/Incorrect: 
Student response is inadequate or incorrect.

Part B:

Level of Pollutant for Site B

Complete: 
Student response lists the four pollutants tested in Table 1B and the correct level for each pollutant. The correct results are shown in the table.

Essential: 
Student response lists at least three pollutants in Table 1B and the correct levels for three pollutants.

Partial:
Student response lists at least one pollutant in Table 1B and the correct level for the pollutant.

Unsatisfactory/Incorrect: 
Student response is inadequate or incorrect.

Composite Score: 

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

Now add the test results from the outside laboratory (Reference Chart 3) to columns one and two of Tables 1A and 1B. Remember to write the results from sample S_A in Table 1A and the results from sample S_B in Table 1B.

Then complete columns three and four of Tables 1A and 1B using the reference materials you have been given in your kit.

When completed, these tables will help you to evaluate the water quality at each proposed town site.

This item was scored in 2 parts:

Part A:  Summary of pollutant levels for Site A
Part B:  Summary of pollutant levels for Site B

Part A

Complete:
Student response shown in Table 1A consists of two parts.

Student response is scored based on the interpretation of the results indicated in Table 1A. There is no penalty for providing incorrect water test results or for copying pollutant levels incorrectly from Chart 3. Since pH falls below the acceptable limits at Site A, indicating Yes or No for exceeding the maximum level allowed is acceptable.

Partial:
Student response shown in Table 1A indicates correct interpretation of the results and a valid source of the pollutant(s) that exceed the maximum level allowed for 2-9 of the total of 10 pollutants.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Part B

Complete:
Column 3 shows a correct interpretation of the results in Column 2, indicating whether or not each pollutant level exceeds the maximum level allowed based on Chart 2 and the results in Column 2. 

Student response is scored based on the interpretation of the results indicated in Table 1B. There is no penalty for providing incorrect water test results or for copying pollutant levels incorrectly from Chart 3.

Partial:
Student response shown in Table 1B indicates correct interpretation of the results and a valid source of the pollutant(s) that exceed the maximum level allowed for 2-9 of the total of 10 pollutants.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Composite Score:

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

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