Mousetrap Car PCA Scenario Map, Results, and Scoring Rubric. Scenario Type: Application in a Physical Source: Fender Bender Physics, NSTA Press 2002

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1 Title: Mousetrap Car Author: Roy Beven Grade: High School Scenario Type: Application in a Physical System Source: Fender Bender Physics, NSTA Press 2002 Description: Students prepare for a Mousetrap Car Challenge by scientifically designing how to connect a mousetrap to a car so the resulting mousetrap car travels far. Item Description WASL Evidence of Learning for the Grade Level Expectation Grade Level Expectation & WASL Evidence of Learning Codes Systems of Nature Properties of Systems Structure of Systems Changes in Systems Inquiry in Science Application of Science Answers & (Field tested in 3 high schools with just over 200 students) A B C D 1 Identify the scientific concepts relevant to regional human problems. AP01a % 10.5% 3.8% 84.3% 2 Determine the average speed of an object during a given time interval when the object is moving in a straight line. PR02b % 18.5% 7.1% 48.8% 3 Compare the kinetic energy of parts of the systems at various locations or times. PR04c % 37.2% 22.7% 15.0% 4 Explain the effectiveness of the solution to a problem/challenge using scientific concepts. AP03b See Short Answer Rubric 5 Describe a physical system s total energy in terms of energy conservation. ST02d % 46.2% 33.7% 7.7% 6 Identify how unbalanced forces change the motion of a more massive car. CH02a % 82.3% 6.2% 2.4% 7 Describe energy transfers ST02a See Short Answer Rubric 8 Identify the input to the mousetrap car system. Identify the sum of all the forces acting on an object CH01b % 16.9% 23.4% 14.0% 9 Identify how the method of investigation ensured reliable results. IN09a % 74.0% 4.8% 13.0% Propose the stages of a scientific design 10 process to solve a problem/challenge. Scenario = 15 pts 2pts 13% 3pts 20% 2pts 13% High School Science WASL = 62 pts 10% 14% 16% balanced among physical, Earth/space, and living systems Systems = 40% 1pt 7% AP02a pts 47% 40% 20% See Extended Response Rubric 7pts or 47% MC, 4pts or 27% SA, 4pts or 27% ER 28 pts or 45% MC, 22 pts or 36% SA, 12 pts or 19% ER First published by the Science Assessment Team of the Washington Office of the Superintendent of Public Instruction on January 17, Copyright 2006 by Washington Office of the Superintendent of Public Instruction (OSPI) All rights reserved. Educational institutions within the State of Washington have permission to reproduce this document. All other individuals wishing to reproduce this document must contact OSPI. 2 1 September 30, 2006

2 Scoring Rubric and for Item 4: Evaluate the Solution Performance Description A 2-point response demonstrates the student understands the GLE: Evaluating Potential Solutions AP03b (3.1.3) Evaluate consequences, constraints, and applications of solutions to a problem or challenge BY explaining the reasons for the effectiveness of the solution to the problem. Mean = 0.75 pts The response explains why Lauren and Drew s mousetrap car traveled so far by: Identifying two features of their mousetrap car that helped the car travel so far. AND Giving reasons, in terms of the force, for the effectiveness of each feature. Examples: Features of their mousetrap car Extended lever arm Trap opened 180 Loosely connected string to axle Thin metal lever arm extension Wheels Reasons for effectiveness in terms of force Lowers the force on axle/wheels/floor so wheels will transfer all their motion to the car wheels will not slip so they move the car Stores the most force/work/energy so car has more forward force to make the car roll / kinetic energy Car can roll after the trap has closed because the string will not force the axle to stop spinning Light weight to minimize weight therefore less friction stopping the car less friction stopping the car compared to sliding without wheels lined up so car rolls straight without too much friction Note: Response must use an acceptable term to identify the feature and the must connect an acceptable term for force as a reason for the motion of the mousetrap car as shown in the bold terms above. 26% A 1-point response demonstrates the student has partial understanding of the GLE. The response explains why Lauren and Drew s mousetrap car traveled so far by identifying one feature of their mousetrap car that helped the car travel so far with a reason, in terms of the force, for the effectiveness of the feature. 30% A 0-point response demonstrates the student has little or no understanding of the GLE. 40% Blank = 4% 2 September 30, 2006

3 Scoring Rubric and for Item 4: Evaluate the Solution (continued) Notes: 1. Responses using other terms (e.g. give examples) may be credited for identifying a feature of the mousetrap car. 2. Responses using common terms (e.g. rubbing, pull, push, work, weight, friction) may be credited for using the term force. 3. Response restating the reason from the Plan Summary (i.e. so the lever arm will apply a small force over a large distance.) cannot be credited as a reason for a feature. 4. Responses demonstrating misconnections directly related to the motion of the car may not receive two score points (e.g. longer lever created more energy so the car goes farther). 3 September 30, 2006

4 Performance Description Item 7: Energy Transfers A 2-point response demonstrates the student understands the GLE: Energy Transfers and Transformations ST02a (1.2.2) Analyze energy transfers and transformations within a physical system, including energy conservation BY describing how energy is transferred or transformed within and among physical systems. Points Mean = 0.40 pts The response describes two energy transfers in the mousetrap car that happened while the car was moving by: Identifying the form of energy before and after each transfer. AND Describing where the energy transfers happened. Example: The potential energy in the spring of the mousetrap was transformed into kinetic energy while the spring opened the extended lever arm. The kinetic energy of the lever arm was transferred to the car through the string connecting the lever arm to the drive axle. 4 8% Other examples of energy transfers in this system: Form of energy before and after Where the energy transfers happened Chemical/food/mechanical to potential Opening the spring/mousetrap/lever arm Potential to kinetic (+heat) While spring/mousetrap/lever arm is closing Kinetic to kinetic (+heat) Lever arm to axle/wheels/car Kinetic to heat/sound While car is stopping A 1-point response demonstrates the student has partial understanding of the GLE % A 0-point response demonstrates the student has little or no understanding of the GLE % Blank = 9% 4 September 30, 2006

5 Scoring Rubric for Item 7: Energy Transfers (continued) Attributes of a Description for Awarding Points Note: The italicized print is the part of the Example credited for the value point. Performance Description Points One energy transfer: The potential energy in the spring of the mousetrap was transformed into kinetic energy Where transfer happened: The potential energy in the spring of the mousetrap was transformed Attribute Note: This point may only be credited with an attempt to identify the energy forms involved in a correct transfer (e.g. there was an energy transfer in the spring). Another energy transfer: The kinetic energy of the lever arm was transferred to the car 1 25% 1 80% 1 41% Where transfer happened: The kinetic energy of the lever arm was transferred to the car Attribute Note: This point may only be credited with an attempt to identify the energy forms involved in a correct transfer (e.g. the lever arm transferred energy). Total Possible Points % 5 September 30, 2006

6 Notes: Scoring Rubric for Item 7: Energy Transfers (continued) 1. Incorrect Transfers/Transformations: Responses describing a clearly incorrect energy transfer or transformation may not be credited 2 score points. However, responses may use the terms transfer and transformation interchangeably. 2. Transfers: Responses may be credited as correctly describing energy being transferred from one object to another by identifying the two objects and the energy form (e.g. kinetic energy in the lever arm is transferred to the axle.) 3. Transformations: Responses may be credited as correctly describing energy being transformed from one form to another by identifying one object, and identifying the energy forms before and after the transformation (e.g. potential energy in the spring is transformed into kinetic energy). 4. Energy Terms as Verbs: Responses using a verb when describing an object s energy change may not be credited as identifying the energy form (e.g. sunlight heating the water cannot be credited for light to heat energy). 5. Unexpected Responses: Responses describing a possible single unexpected energy transformation from the input energy to energy in the specified part of the system may earn 2 score points. (E.g. When asked to describe energy transformations from the Sun to fish, a full-credit, unexpected response could be: Fish can be warmed as light energy from the Sun transforms into heat energy in the fish.) 6. Synonyms for Energy Forms: Responses may be credited as correctly identifying an energy form when the following acceptable terms are used as nouns. a) heat energy: heat, thermal energy b) sound energy: sound, sound waves, vibration energy c) light energy: light, sunlight, light waves, light beams, radiant heat, light rays, solar energy, gamma/ultraviolet/infrared rays, electromagnetic waves d) electrical energy: electricity, voltage, electric current e) kinetic energy: energy of motion, mechanical energy f) potential energy: energy of position, elastic energy, mechanical energy, gravitational energy g) chemical energy: bond energy, food energy, food, glucose, ATP, energy-rich molecules, sugar, starch h) nuclear energy: radioactive energy i) wave energy: light energy, sound energy 6 September 30, 2006

7 Scoring Rubric for Item 10: Design a New Solution Performance Description A 4-point response demonstrates that the student understands the GLE: Designing and Testing Solutions AP02a (3.1.2) Evaluate a scientific design process used to develop and implement solutions to problems or challenges by proposing the stages of a scientific design process to solve a problem or challenge Points Mean = 1.9 pts % A 3-point response demonstrates that the student partially understands the GLE % A 2-point response demonstrates that the student has limited understanding of the GLE % A 1-point response demonstrates that the student has very little understanding of the GLE. A 0-point response demonstrates that the student has almost no understanding of the GLE % 10% 0 1 Blank = 3% Attributes of a Scientific Design Process for Awarding Points Design Process Stage Description of Stage Point Gather Information Gather Scientific Information Information needed to solve the Problem or pertinent questions are described (e.g. measure the force of an extended lever arm, measure the frictional force between the wheels and the floor). 1. Listing objects given in the prompt or scenario cannot be credited. 2. Repeating an appropriate process from the scenario can be credited. Related scientific information or how to scientifically collect related data is described (e.g. investigating the effect of the lever arm length on the force, investigating the frictional forces for the different wheels). 1. Scientific information involves general concepts (e.g. frictional forces between various materials). 2. Scientific collecting of data involves systematically collecting pertinent data over a period of time. 1 50% 1 5% 7 September 30, 2006

8 Scoring Rubric for Item 10: Design a Solution (continued) Attributes of a Scientific Design Process for Awarding Points (continued) Design Process Stage Description of Stage More than one idea that could solve the problem is described (e.g. use rubber wheels, make the trap s wooden base shorter and thinner, mount the trap above the rear wheels). Point Explore Ideas Explore Scientific Ideas 1. Listing objects may not be credited. 2. Ideas may involve materials not given. 3. A sentence should be read as one idea (e.g. Use a container with soil and gravel is one idea, not two or three). Run-on sentences may be read as more than one idea. Sentences containing the term or may be read as more than one idea (e.g. Use a metal, plastic, or glass container is three ideas). An idea includes scientific concept(s) for considering the idea. (e.g. use rubber wheels to grab the floor with a greater force, cut the base of the trap so the trap can be opened wider to apply more force to the wheels, mount the trap high above the rear wheels so the force is more directly transferred to the axle). Stage Note: This point may be credited even when only one idea is given. 1 60% 1 6% 8 September 30, 2006

9 Scoring Rubric for Item 10: Design a Solution (continued) Attributes of a Scientific Design Process for Awarding Points (continued) Plan Stage: This stage is divided into three related smaller stages, Plan Summary, Steps to do the Plan, and Labeled Diagram of Solution. Matching Rule: The Plan Summary, Steps to do the Plan, and Diagram of Solution should include the same materials. A point may not be credited for any stage that omits/adds major materials included in credited stage(s). Scoring Technique: When applying the Matching Rule to the Plan Summary, Steps to do the Plan, and Diagram of Solution, award a value point to the first creditable stage then check for matching with the other stages. However, a response should be awarded the maximum possible points so this is not a rule but a technique. Clarifying Vague Terms and Steps: A vague term or step can be clarified by referring to any of the three smaller plan stages (e.g. A step in the plan like Now add all the other materials can be clarified if the other materials are listed in the Plan Summary or clearly labeled in the Diagram of the Solution). Design Process Stage Description of Stage Point A simple plan summary is given with at least one reason for selecting one of the solutions/materials (e.g. Use a short lever arm to apply a greater force on the axle). Plan Summary Steps of the Plan Diagram of Solution Labeled Diagram of Solution 1. The given problem cannot be credited as a reason. 2. A reference to a solution in Explore Ideas may be credited (e.g. I chose all these ideas because ). 3. Responses violating any non-material aspect of the Challenge Rules in any stage except Explore Idea may not be credited for this value point. For materials violations, use general Note 3. The steps are clear, logical, and complete. 1. One-step plans cannot be credited. However, a single step that indicates more than one action can be credited as two or more steps (e.g. Attach the trap above the rear axle with rubber wheels using a string in between). 2. A copy of the Plan Summary cannot be credited. A diagram of the solution or steps to solve the problem is given. Stage Note: The Matching Rule does not apply to an un-labeled diagram. The diagram is complete and the objects or processes key to carrying-out the plan are labeled (e.g. parts of the car like the wooden base do not need to be labeled). 1 25% 1 50% 1 55% 1 40% 9 September 30, 2006

10 Scoring Rubric for Item 10: Design a Solution (continued) Attributes of a Scientific Design Process for Awarding Points (continued) Design Process Stage Description of Stage Point Test Solution Scientifically Test Solution The test describes at least one measurement that relates to the effectiveness of the solution. (e.g. measure and record the time for the car to travel 3.0 meters four times). 1. This point may not be awarded when the test gives or implies artificial data (e.g. My dragster was the fastest). 2. The test may be included in the plan stages. The test includes measuring the before-after or input-output of all pertinent variables (e.g. give example) OR the test includes regularly measuring all pertinent variables in a consistent manner (e.g. give example). Stage Note: This point may be credited even if a test gives or implies artificial data. 1 35% 1 25% Total Points P 10 Notes: 1. Inappropriate Plans: Responses that change the problem (e.g. lightest dragster) or give a plan that cannot possibly solve the problem may only be credited the four value points associated with the Gather Information and Explore Ideas stages. 2. Materials in Plans: Responses that include materials in the plan stages that are not given or allowed in the item, may not receive value points for any of the plan stages in which these materials are included (e.g. bigger mousetrap). However responses may include material(s) or changes from the original scenario s solution; even if the item does not indicate the material(s) or change is a possibility (e.g. give example). 3. Copying the Scenario: Responses that copy the whole scenario cannot be credited any value points. However, responses that appropriately copy a stage from the scenario may be credited. 10 September 30, 2006