Study Guide

Field 113: Physical Science 
Sample Constructed-Response Assignment

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Test Directions for the Constructed-Response Assignment

This section of the test consists of one constructed-response assignment. You will be asked to prepare a written response of approximately  300 to 600  words on the assigned topic.

Read the assignment carefully before you begin your response. Think about how you will organize your response. You may use the erasable sheet(s) to make notes, write an outline, or otherwise prepare your response. However, your final response to the assignment must be either:

  1. typed into the on-screen response box,
  2. written on a response sheet and scanned using the scanner provided at your workstation, or
  3. provided using both the on-screen response box (for typed text) and a response sheet (for calculations or drawings) that you will scan using the scanner provided at your workstation.

Instructions for scanning your response sheet(s) are available by clicking the "Scanning Help" button at the top of the screen.

As a whole, your response must demonstrate an understanding of the knowledge and skills of the field. In your response to the assignment, you are expected to demonstrate the depth of your understanding of the content area through your ability to apply your knowledge and skills rather than by merely reciting factual information.

Your responses to the assignments will be evaluated based on the following criteria.

PURPOSE: the extent to which the response achieves the purpose of the assignment
SUBJECT KNOWLEDGE: appropriateness and accuracy in the application of subject knowledge
SUPPORT: quality and relevance of supporting evidence
RATIONALE: soundness of argument and degree of understanding of the subject area

The constructed-response assignment is intended to assess subject matter knowledge and skills, not writing ability. However, your response must be communicated clearly enough to permit valid judgment of the scoring criteria. Your response should be written for an audience of educators in this field. The final version of your response should conform to the conventions of edited American English. Your response must be your original work, written in your own words, and not copied or paraphrased from some other work.

Be sure to write about the assigned topic. Remember to review your work and make any changes you think will improve your response.

Any time spent responding to the assignment, including scanning the response sheet(s), is part of your testing time. Monitor your time carefully. When your testing time expires, a pop-up message will appear on-screen indicating the conclusion of your test session. Only response sheets that are scanned before you end your test or before time has expired will be scored. Any response sheet that is not scanned before testing ends will NOT be scored.

Sample Constructed-Response Assignment

Use the information in the exhibits to complete the assignment that follows.

Analyze the information provided in the exhibits and, citing specific evidence from the exhibits, write a response of approximately 300 to 600 words in which you:

Class Context

Students in a high school physical science class have been investigating waves and wave properties. Previous lessons and investigations completed as part of this unit focused on topics such as the various types of waves, the relationship between period and frequency, and how to measure the wavelength of a transverse wave. Students are familiar with the use of various tools designed to measure wave properties. Students have experience writing laboratory reports, including collecting, presenting and analyzing data, and drawing reasonable conclusions.

Excerpt from Lesson Plan

The following is an excerpt from a high school physical science class's lesson plan.

Unit Subject: Wave Characteristics and Properties

Subject of the Lesson: Wave Speed in a Ripple Tank

Student Content Standard:

HS-PS4-1 Students who demonstrate understanding can: use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves in various media1.

Lesson Objectives:

Materials:

Assessment:

Students will be evaluated on the basis of a completed laboratory report, including data table, an analysis section, and a conclusion that addresses specific questions.

Sample of Student Work

Student Data Table

Trial Motor Speed (rev per min) Wavelength (m) Wave frequency (Hz) Wave speed (m per s)
1 150 0.34 2.5 0.85
2 120 0.46 1.9 0.87
3 90 0.60 1.5 0.90
4 60 1.02 0.90 0.92

Student Analysis of Data

Description

We set up a ripple tank and filled it with water about 8 cm deep. In each trial, we adjusted the speed of a motor attached to a wooden rod to create water waves at a given frequency. We took pictures of the water waves with a camera and measured their wavelengths in these pictures with a meter stick. We also calculated the waves' frequencies by counting the number of wave crests passing by reference point in 10 seconds and dividing by 10.

Analysis and Conclusion

After finding the wavelengths and frequencies of the water waves in each trial, we calculated wave speeds. We did this by multiplying the wavelength, in meters, by the frequency, in Hertz. This gave wave speed in units of meters per second. We found that wave speed was not constant across the trials. Instead, as the wavelength increased, the wave speed also increased, going from 0.85 m per s at a wavelength of 0.34 m to 0.92 m per s at a wavelength of 1.02 m.

Sample Strong Response to the Constructed-Response Assignment

One strength is that the student tested wave speeds at different motor speeds. This shows the characteristic of the relationship between wavelength and frequency. As the motor speed increases an inverse relationship is observed. One weakness in the experiment is the presumption that the small increasing trend is highlighted and claimed to be a result of the procedure.

The student could improve this experiment by measuring the waves several times at each motor speed. By doing this, the results at each motor speed could be averaged to get a more accurate result. This replication could happen in several different ways. The easiest would be to pool all of the data from the entire class. The second would be to have each student or group conduct the experiment several times at each motor speed.

Pooling the data from the entire class would be faster, although it would take time for the data to be collected and distributed. However, there are some potential issues with this method: slight differences in the motors themselves, how the controls are set, the size of the wooden rods, the depth of the water, the elasticity of the suspension cords, and several other minor differences between setups could result in slight variations in the results. This could be addressed by standardizing all of the factors before the experiment, but this would take some time.

Having each student or group do the experiment several times at each motor speed would provide more precise results. There would be no variation due to different equipment, set-up, or skill level of the students. Since students would be collecting all of their own data, replication would be more reliable. However, this would take more class time to do.

It appears the student followed the instructions as directed. However, there are some concerns with the analysis. They understand the basic concepts of the relationship between wavelength, frequency, and wave speed. The results do not seem realistic. The student could not have measured wavelengths of 1 meter in a ripple tank, even large ripple tanks are not a meter long. The student must have miscalculated the picture of the waves in determining the wavelengths. I would be sure to verify the students know how to use all of the equipment before the experiment. Additionally, the results, while mathematically correct, are not accurate or realistic. A student cannot have a wavelength of 1 meter if the wooden rod is generating waves 60 times per minute. The student's results are off by orders of magnitude and students should be able to identify when results are not realistic. By observing the experiment, the student should know that the wavelengths were not 1 meter wide, the student should learn to internally verify the precision of their results. Whatever field of science, students should know how to identify errors in interpretation, measurement, as well as variation as sound Physical Science knowledge requires both accuracy and precision in results.

Rationale for the Sample Strong Response

Please note that the response is evaluated based upon the four performance characteristics of Purpose, Subject Matter Knowledge, Support, and Rationale. Please also note how the score point descriptions are based upon how the examinee attends to the performance characteristics. You should be very familiar with the CEOE performance characteristics and score scale and refer to them when reviewing this rationale.

The response fulfills the purpose of the assignment (refer to the instructions for the assignment) by demonstrating general knowledge and understanding of the subject matter. The purpose of the assignment is largely achieved as the writer provides a general response to all three bullets in the prompt. The writer identifies a significant strength as well as a significant weakness in the student's work. The strength identified as testing the concept at different speeds indicates the writer understands the relationship must be tested under different conditions (in this case different rates in which waves are generated). Additionally, the writer correctly identifies replication as an important part of an experiment and stated why replication is required in such experiments. The writer describes appropriate means to address the weakness in the study, offering more than one option to correct the concern. The writer provides both positive and negative aspects to each resolution given. The writer's statements as to the purpose and potential benefits and drawbacks of each resolution offered indicate a general understanding of the specified concepts. The writer provides sufficient evidence that is generally appropriate and that generally supports the discussion. Overall, this response reflects a general understanding of Physical Science.

Sample Weak Response to the Constructed-Response Assignment

One strength is that the student conducted the experiment several times. This shows the importance of replication which validates the results of your experiment. One weakness in the experiment is the student failed to measure wave amplitude. Wave amplitude, or the difference between the crest and trough of each wave, is an important part of the wave's energy. The more energy the wave has, the faster it will travel.

The student could improve this experiment by photographing not only the wavelength, but having a second camera at a 90 degree angle to the first and measuring the height of each wave as well. The student would need a second meter stick placed vertically behind the ripple tank for this. The instructor needs to provide not only another meter stick to be taped on the wall vertically behind the ripple tank, but a second camera as well. It would be best if the cameras were synchronized so the student could measure the same wave for wavelength and wave amplitude. More energetic waves will move faster.

The student did not record wave amplitude but that is likely from a mistake in the instructions. Accuracy is important in physical science and all science practices. Instructions need to be accurate and complete or the students will get confused. I would do the experiment first myself pretending to be a student to make sure the instructions are clear and easy to follow. As the instructor I would make sure I understand the relationship between waves, speed, and energy before trying to teach my students. I also would make sure my students know how to write a lab report properly. I would tell my students to make a graph of the results so they could interpret what the data are telling us. The class then could apply the information to real world situations and discuss things like currents in the ocean and boats move slower against the current and that they should always travel with the current to save fuel.

Rationale for the Sample Weak Response

Please note that the response is evaluated based upon the four performance characteristics of Purpose, Subject Matter Knowledge, Support, and Rationale. Please also note how the score point descriptions are based upon how the examinee attends to the performance characteristics. You should be very familiar with the CEOE performance characteristics and score scale and refer to them when reviewing this rationale.

The purpose of this assignment (refer to the instructions for the assignment) is only partially achieved. The writer provides an incomplete purpose in his or her response. The writer recognizes the importance of replication in an experiment but fails to understand that replication means doing the experiment the same way multiple times, not changing the conditions. While wave amplitude is a factor in wave energy, it is not relevant in this discussion of wave speed. Unfortunately, this error propagates throughout the writer's response. The writer uses this error to attempt to support the position on improving the area of need. The writer's understanding of the concept is limited and the conclusions are poorly reasoned from the lack of subject matter understanding. Having a real world example students can relate to is a good idea, but the example the writer uses is only minimally related to the concept in the question, again drawing from erroneous conclusions of how wave amplitude is related to wave speed. Overall, the response reflects a limited application of subject matter knowledge and a poorly reasoned understanding of the topic.

Performance Characteristics

The following characteristics guide the scoring of responses to the constructed-response assignment.

Characteristics that guide the scoring of responses
Purpose The extent to which the response achieves the purpose of the assignment
Subject Matter Knowledge Accuracy and appropriateness in the application of subject matter knowledge
Support Quality and relevance of supporting details
Rationale Soundness of argument and degree of understanding of the subject matter

Scoring Scale

Scores will be assigned to each response to the constructed-response assignment according to the following scoring scale.

Score Scale with description for each score point.
Score Point Score Point Description
4  start bold The "4" response reflects a thorough knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is fully achieved.
  • There is a substantial, accurate, and appropriate application of subject matter knowledge.
  • The supporting evidence is sound; there are high-quality, relevant examples.
  • The response reflects an ably reasoned, comprehensive understanding of the topic.
3  start bold The "3" response reflects a general knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is largely achieved.
  • There is a generally accurate and appropriate application of subject matter knowledge.
  • The supporting evidence generally supports the discussion; there are some relevant examples.
  • The response reflects a general understanding of the topic.
2  start bold The "2" response reflects a partial knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is partially achieved.
  • There is a limited, possibly inaccurate or inappropriate application of subject matter knowledge.
  • The supporting evidence is limited; there are few relevant examples.
  • The response reflects a limited, poorly reasoned understanding of the topic.
1  start bold The "1" response reflects little or no knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is not achieved.
  • There is little or no appropriate or accurate application of subject matter knowledge.
  • The supporting evidence, if present, is weak; there are few or no relevant examples.
  • The response reflects little or no reasoning about or understanding of the topic.
U The response is unscorable because it is illegible, not written to the assigned topic, written in a language other than English, or lacking a sufficient amount of original work to score.
B There is no response to the assignment.

References

1. Republished with permission of The National Academies Press, from Next Generation Science Standards: for states, by states - HS-PS4-1 Standards; permission conveyed through Copyright Clearance Center, Inc.