Week 8 Response
A fourth-grade lesson on simple
machines integrates performance
assessment tasks.
More and more science teachers are integrating perfor-mance assessment tasks into their lessons. These tasks are a means of assessing conceptual understanding while providing students with various opportunities to demonstrate learning outcomes. Performance assessment tasks typically engage students in authentic, real-world, hands-on learning situations and impose high cognitive demands resulting in meaningful learning (Darling-Hammond 2004). Information gleaned from performance assessments not only support sci- ence teachers’ understandings of the strengths and weaknesses of the students but also guide their instruction in ways that will develop the knowledge and mental skills required to construct appropriate mental models for authentic performance situa- tions. Performance assessment tasks comprise a performance that may be observed and/or a tangible product that may be examined (Bass, Contant, and Carin 2009). Examples include oral presentations, debates, exhibits, written products, con- struction of models, and solutions to problems. In creating ef- fective performance tasks, science teachers should consider the following factors: the focus of the task, the context of the task, directions provided for the students and the rubric used for as- sessment. The focus of the assessment task should be closely aligned with the learning objectives and the context should provide a background and a question related to the focus objec- tives. Additionally students must be provided with directions
By Cheryl A. McLaughlin, Felecia C. McLaughlin, and
Rose M. Pringle
Science and Children50
A fourth-grade lesson on simple
machines integrates performance
assessment tasks.
that clearly describe the performance and/or the product to be assessed as well as a scoring rubric for evaluating the quality of the performance task.
Connecting to NGSS The following performance assessment tasks align with Next Generation Science Standards (NGSS) because stu- dents were provided with the opportunity to engage in scientific investigations and engineering practices that re- lated to disciplinary core ideas (Achieve Inc. 2013). The engineering practices integrated in the performance as- sessment tasks include Asking Questions and Defining Problems, Planning and Carrying Out Investigations, and Constructing Explanations and Designing Solutions (disciplinary core idea 3-5-ETS1: Engineering Design). These fourth graders were given opportunities to draw on scientific ideas as they designed and constructed mod- els to represent their understanding of simple machines. This activity allowed students to develop their own un- derstanding of the concept and to gain an appreciation for the way engineers operate. According to A Framework for K–12 Science Education (National Research Coun- cil [NRC] 2012), engineering practices are distinct from those of scientists, and include developing design plans, producing and testing models and prototypes, and refin- ing design ideas based on the performance of a model or prototype. In this lesson, we adapted these expectations to match the cognitive abilities of these enthusiastic fourth graders.
The Next Generations Science Standards point to the importance of a continuum of learning in science. This is done through story lines and specific standards for each grade, K–5. The lessons described here were developed prior to the release of NGSS and the disciplinary core ideas developed through these investigations do not align precisely with the recommended grade levels found in NGSS. This is probably a situation many teachers find themselves in at this time. We will eventually modify the lessons and possibly shift some of the practices and core ideas to other grade levels. But, we have found that this is when our students are ready for this learning experience. They will build on it during subsequent years through the progression of learning we currently have in place. The focus of this lesson is standard 3-PS2 Motion and Stabil- ity: Forces and Interactions. NGSS specifies that in kin- dergarten students “Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object” (performance expectation K-PS2-1; see Connecting to the Standards). They use the practice of planning and carry- ing out investigations and develop understanding of the disciplinary core ideas PS2.A and ETS1.A. In grade 3 the
NGSS takes them on to performance expectation 3-PS2- 1, “Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object” (see Connecting to the Standards). In both kindergarten and grade 3 the crosscutting concept Cause and Effect is emphasized. We have taken this on into fourth grade.
This article presents the experiences of Miss Fele- cia McLaughlin, a fourth-grade teacher from the island of Jamaica who used the model proposed by Bass et al. (2009) to assess conceptual understanding of four of the six types of simple machines while encouraging collabora- tion through the creation of learning teams. Students had an opportunity to demonstrate what they learned and un- derstood about simple machines through the construction of scientific models and the oral presentation of the mental processes involved in the generation of their products. The topic Simple Machines is typically taught in grade 4 as part of a unit entitled Simple and Complex Machines. The unit explores how ideas such as force, push, pull, and work are related to simple machines and may also be adapted to suit the needs of fifth and sixth graders. This performance assessment activity was conducted in a single lesson after the basic concepts of simple machines were developed in two prior classes, and the main objective was to have stu- dents design and construct simple machines that complete particular tasks. The successful completion of these tasks would demonstrate students’ comprehension of the con- cepts taught and their ability to integrate them into their everyday experiences.
Miss McLaughlin’s Lesson The lesson took place in two 30-minute sessions over a period of two days. Miss McLaughlin introduced the stu- dents to six simple machines: pulley, lever, wheel and axle, wedge, screw, and inclined plane. During the lesson, she showed them physical examples and photographs of each simple machine and encouraged them to provide a de- scription of each in their own words. From the discussion, Miss McLaughlin and the class collectively completed a vocabulary chart that defined the distinguishing feature(s) of each simple machine. They then engaged in further dis- cussions as students shared other examples of simple ma- chines that they had encountered in their everyday experi- ences. Toward the end of the class, Miss McLaughlin gave the students a record sheet on which they had to identify simple machines from diagrams and to justify their re- sponses using the information from the vocabulary chart.
The second lesson provided an opportunity for stu- dents to apply their knowledge of simple machines to the spaces outside of the classroom in which they were comfortable. Students worked in groups to find, identify,
November 2013 51
and observe one simple machine on the school grounds. Miss McLaughlin gave them a record sheet with specific questions about the machine they selected. For instance, they were asked: What is the object? What type of simple machine is it? Is it made up of more than one simple ma- chine? If so, list them. How does this machine make a job easier? During the class discussion that took place after the scavenger hunt, students spoke about the flagpole pul- ley system in the school yard explaining that the rope was wrapped around a wheel at the top making it easier to raise and lower the flag. Another group selected the doorknob as a type of wheel and axle, explaining that the axle portion was in the door and the wheel was the part that turns to make the door easier to open.
The Performance Assessment The focus of the activity was to allow students to demon- strate their understanding of simple machines by creating appropriate models related to everyday assigned tasks. Spe- cifically, Miss McLaughlin wanted students to demonstrate their understanding of how simple machines operate to make everyday work easier. In addition, they were required to identify simple machines used during routine activities at home, at school, and in various places of employment.
Simple Machine Selection Students selected one of the four simple machine groups: pulley, wheel and axle, inclined plane, and lever. The oth- er two simple machines, screws and wedges, were not as- signed because students demonstrated mastery of the con- cepts underlying their operation and could easily identify them within various contexts. Each group was assigned a task sheet with a problem that connected with the context of the students’ experiences to create opportunities for au- thentic learning. The problem presented for each machine is described in the following sections.
Pulley
Your mother wants you to collect water from the hand- drawn water well in your backyard. The well is half-filled with water. Create a machine that will make this work easier for you.
Wheel and Axle
Robert works on a construction site and has to remove a pile of cement blocks all at once from one location to the next. Create a model of a machine that will assist him.
Inclined Plane
A mover is trying to get a sofa into the back of his truck. There is no one to assist him. Create a machine that will help him accomplish this goal.
Lever
Your father is trying to remove family portraits on the wall of the living room. Create a machine that will help him remove the nails or fasteners in the wall.
Design and Constuction In order to anticipate and accommodate a wide range of needs, Miss McLaughlin made the following materials available to students:
Cord/string Drink cartons Butcher paper Crayons/markers Ruler Thread spool Styrofoam cups Wooden skewers Scissors Paper Drinking straws Pipe cleaner Cloth Cardboard Duct/scotch/masking tape Medicine cups Elastic bands Safety goggles
The students were required to discuss and negoti- ate their ideas in order to conceptualize a possible design for the machine to be used for each scenario. They were encouraged to sketch possible designs as they worked in groups. After collecting appropriate materials, students were expected to construct their machine then draw a la- beled diagram for presentation to the class. Their posters also included definitions of the simple machines depicted as well as other relevant information that was discussed during their collaboration. Members of each group were assigned the following roles: • Machine engineer—required to lead the construction
process • Designer—responsible for sketching and modifying
ideas of the group • Materials manager—in collaboration with the group
decided on appropriate materials for the project • Note-keeper—made notes as the discussion pro-
gressed • Presenter—presented the final product to the rest of
the class.
Science and Children52
Simply Performance Assessment
F i g u r e 1.
Rubric assessing the process.
Process All of the time 4
Most of the time 3
Some of the time 2
None of the time 1
Total
Assisting—students were observed helping each other and working with each other’s idea
Participating—students were observed contributing to the project
Negotiating—students were observed exchanging and defending their ideas
Supporting—students were observed encouraging and supporting the efforts of others
Organizing—students were observed effectively managing their time
F i g u r e 2 .
Rubric assessing the product.
Product excellent 3 good 2 Fair 1 Total
Disciplinary Core Ideas
Explanations indicated a clear and accurate understanding of the scientific principles underlying the construction of the machine.
Explanations indicated a relatively accurate understanding of the scientific principles underlying the construction of the machine.
Explanations did not indicate a clear and accurate understanding of the scientific principles underlying the construction of the machine.
Illustration Plan is neat with clear labeling for all components.
Plan provides labeling for most components.
Plan is not adequately labeled.
Construction Appropriate materials were selected and creatively used to highlight specific aspects of simple machines.
Appropriate materials were selected but construction did not highlight important aspects of simple machine.
Materials selected were inappropriate and did not highlight any aspect of simple machines.
Effort The product was well thought out and obvious effort was made in its construction.
The product was well thought out but one or two details could have been refined for a neater product.
The product was not well thought out and more details were necessary for a neater product.
(Adapted from rubistar.4teachers.org)
November 2013 53
Beyond the specific goals listed, all students were expected to collaborate in a manner that ensured that the machine they designed and constructed ad- dressed the specific needs out- lined in their performance task.
Miss McLaughlin reminded students about safety concerns, especially related to the use of pipe cleaners, scissors, and skewers. Groups selecting these tools were given goggles and were carefully and routinely monitored. As the stu- dents got started, their enthusiasm was palpable. The teacher could hear them commenting on each other’s ideas and telling about past experiences during which they felt sure that a simple machine was used to achieve various outcomes. This provided another opportunity to assess their learning.
Using the scoring rubrics to guide assessment, Miss McLaughlin evaluated both the process (see Figure 1 on p. 53 and NSTA Connection) and the product (see Fig- ure 2 on p. 53 and NSTA Connection). The rubrics were explained to the students prior to the project to allow for a clear understanding of the criteria used for assessment. Miss McLaughlin also wanted the evaluation to be as ob- jective and consistent as possible, using scores to deter- mine the extent to which the performance objectives were met. The students’ constructions are described below.
Pulley
The students who were given the task to gather water from the hand-drawn well used pipe cleaners and a thread spool
to design their pulley system. They inserted the ends of the pipe cleaner into a thread spool and bent it into the form of a circle. String was used to attach a tiny medicine cup at one end while the other end was wrapped around the spool. Students demonstrated how they would use their invention to lower the container to the water and scoop water from the well. I asked students to explain why they believed that their construction was a simple machine. They explained that the system made it easier for them to lift an object against the pull of gravity.
Wheel and Axle
The students in this group created a machine that con- sisted of a small carton box and Styrofoam lids used as wheels. A small wooden skewer was used to attach the wheels to the box (see Figure 3) and a small string was at- tached to facilitate pulling. The students explained that while their creation was a model of a simple machine, ideally the carton should be replaced by a larger contain- er made of metal with larger wheels to accommodate the weight of cement blocks. Students were commended for identifying limitations in their models and also for mak- ing alternative suggestions to offset the weaknesses. Some students indicated that a wheelbarrow is commonly used on construction sites to carry out this specific task. Miss McLaughlin acknowledged that while this is true, the wheelbarrow is considered a complex machine because it consisted of more than one simple machine. She indi- cated that complex machines would be explored during the following week but also challenged them to identify the simple machines that constituted the wheelbarrow. Students quickly identified the wheel and axle and Miss McLaughlin elicited the lever response through further questioning.
Inclined Plane
The simple machine created by this group consisted of a ramp made of a strip of cardboard resting on a truck they constructed from a juice carton (see Figure 4). In their pre- sentation, they identified the truck bed and demonstrated how the mover pushed the sofa up the ramp in order to place it in the truck. The poster illustration consisted of the picture of a truck with the ply board ramp attached and a man pushing the sofa upward. During the presenta- tion, some students indicated that instead of pushing the sofa up the ramp, the mover could have pulled the sofa using rope that was previously secured to the sofa. Oth- ers agreed that the simple machine could also be used to remove the sofa from the truck.
Lever
The students in this group decided to wrap four pipe clean- ers together at one end with scotch tape. After bending
F i g u r e 3 .
Wheel and axle.
Keywords: Simple machines
www.scilinks.org
Enter code: SC111301
Science and Children54
Simply Performance Assessment
Connecting to the Standards Standard 3-PS2 Motion and Stability: Forces and Interactions
Performance expectations: K-PS2-1 Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object. 3-PS2-1 Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.
Science and engineering Practices: Asking Questions and Defining Problems, Planning and Carrying Out Investigations, Constructing Explanations and Designing Solutions
Disciplinary Core ideas: PS2.A: Forces and Motion ETS1.A: Defining and Delimiting Engineering Problems
NGSS Table: 3-PS2 Motion and Stability: Forces and Interactions www.nextgenscience.org/3ps2-motion-stability-forces- interactions
NGSS Table: K-PS2 Motion and Stability: Forces and Interactions www.nextgenscience.org/kps2-motion-stability-forces- interactions
NSTA Connection Visit www.nsta.org/sc1311 for the rubrics.
the other end, they separated the pipe cleaners to create a claw tooth similar to that found on hammers and crowbars (see Figure 5). During their presentation, the students used their invention to demonstrate how a thumbtack could be removed from the board. In the discussion that ensued, several students suggested that in removing the nail from the wall, the arm would be used as a lever. Miss McLaughlin further questioned their understanding of the idea of the arm as a lever by asking relevant questions such as, “Where is the pivot point or fulcrum?” “Where is the effort?” “What is the load?” “Where is the turning point?” and “Is there any other body part that may be used as a lever?”
Learning experiences of this nature not only generate interest in science but also allow students to recognize the importance of science and engineering in addressing many of the problems facing society in the 21st century. n
Cheryl A. McLaughlin (chermac72@ufl.edu) is a doc- toral candidate at the University of Florida in Gaines- ville, Florida. Felecia C. McLaughlin is an elementary school teacher at Kendal All-Age School in Manchester,
F i g u r e 4 .
Inclined plane.
Jamaica. Rose M. Pringle is an associate professor at the University of Florida in Gainesville, Florida.
references Achieve Inc. 2013. Next Generation Science Standards: For
states, by states. Washington, DC: National Academies Press.
Bass, J.E., T.L. Contant, and A.A. Carin. 2009. Teaching science as inquiry. 11th ed. Boston: Allyn & Bacon.
Darling-Hammond, L. 2004. Performance-based assessment and educational equity. Harvard Educational Review 64 (1): 5–31.
National Research Council (NRC). 2012. A framework for K–12 science education: Practices, crosscutting concepts, and core ideas. Washington, DC: National Academies Press.
F i g u r e 5 .
Lever.
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