The History of Computing – EEEEK a Mouse! activity explores the concept of how engineering solved the problem of human/computer interface. Students disassemble a mouse and explore the movement on the X/Y axis that determines mouse positioning.
- Learn about computer/human interface and mouse engineering.
- Learn about ongoing changes to mouse design in response to software changes and human needs.
- Learn about teamwork and the engineering problem solving/design process.
Age Levels: 8-18
Materials & Preparation
Build Materials (For each team)
Required Materials
- One roller ball mouse (or use an old roller ball mouse from your classroom or school computer lab and replace with the new one)
- Eyeglass repair kit or mini screwdriver (must be very small gauge)
- Model construction materials:
- Water-based glue
- Scissors
- Tape
- Ruler
- Paper
- Toothpicks
- Straws
- Spools
Engineering Design Challenge
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Design Challenge
You are a team of engineers given the challenge of disassembling a unusable “track ball” mouse, using the materials provided to you. You will then observe the mechanical parts of the mouse. Next, you will develop and share improvements you would make to eliminate or strengthen an operating feature/part. Finally, you will design and build a model of the part.
Criteria
- Must sketch a design and build a model of the part.
Constraints
- Use only the materials provided.
- Teams may trade unlimited materials.
Activity Instructions & Procedures
- Break class into teams of 3-4.
- Hand out the EEEEK a Mouse worksheet, as well as some sheets of paper for sketching designs.
- Discuss the topics in the Background Concepts Section.
- Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials.
- Provide each team with their materials.
- Explain that students must disassemble an unusable “track ball” mouse, using the materials provided. They will then observe the mechanical parts and see how the “switches” click when the mouse case has been removed. Next, they will determine enhancements they would make to the mouse, based on their observations. Finally, they will develop a model of the new working part(s) of the mouse.
Students will complete the challenge in 4 steps:
● Step One: As a team, disassemble either a new (inexpensive) or old unusable “track ball” mouse, using the materials provided. Be sure that the mouse is not connected to a computer and that no power is flowing through it. You will need to use a very small screwdriver, such as the type commonly found in eyeglass repair kits. Be careful as you pull the plastic cover off the mouse.
● Step Two: Observe the mechanical parts that move when you move the roller ball. Also observe the two or three “switches” and see how they can click when the mouse case has been removed. What is the weakest design aspect of the “track ball” mouse? Why?
● Step Three: Determine how you would improve the design to eliminate or strengthen
the part or operating feature you found in step 2. Sketch your proposed component part, and answer the questions below:
○ What new materials will you need (if any)
○ What materials or parts will you eliminate (if any)
○ How will this new design address the shortcoming you identified?
○ How do you think your new design will impact the cost of this mouse? Why?
● Step Four: Develop a model of the new working part of the mouse using the materials provided. - Announce the amount of time they have to design and build (1 hour recommended).
- Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
- Students meet and develop a plan to complete the 4 steps. For Step 4, they will agree on materials they will need, sketch/draw their plan, and present their plan to the class. Teams may trade unlimited materials with other teams to develop their ideal parts list.
- Teams build their designs.
- Teams present their models to the class and discuss the designs.
- For more content on the topic, see the “Digging Deeper” section.
Time Modification
The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.
Engineering Design Process
Background Concepts
Mouse Operation and Innovation
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The purpose of the computer mouse is to translate human motion (use of the hand) into messages or signals that the computer can translate into directions for moving the screen cursor or to open an application.
X – Y Navigation of the Track Ball Mouse
Inside a standard track ball mouse is a round rubber ball that when moved adjusts the position of either one or two bars which send movement signals that are converted to computer messages telling computer software where to move a cursor on a computer screen. The “bars” usually have a wheel or “optical encoding disks” that usually include 36 holes or slots that allow light to pass. Small, infrared LEDs (light emitting diodes) point to the disk and the pattern or pulses of light that pass through the holes in the disk are converted to “X” and “Y” positions provide computer software with a sense of the distance and direction which the ball has moved. In this way the two dimensional motion of the mouse can be translated into the motion of a pointer within computer software. When you disassemble a track ball mouse in the student activity, you’ll be able to see the two bars, and the optical encoding disks, and how the ball movement impacts these other mechanisms when rolled on a surface.
Click Click Click
The mouse buttons make a “click” noise when pressed for two reasons….one, the pressing pushes on a “micro switch” that incorporates a very stiff piece of metal that snaps….two, the sound has been proven to improve the human/computer interface, giving the user an audible feedback that their finger has caused an action.
Engineered Improvements
Over time, many new engineered improvements have taken the mouse to the next level, or been developed to address specific human needs. For example there are mice with oversized balls on top (instead of underneath) for easier use by very small children or people with physical challenges. There are “roller ball” mice which have additional wheels and switches to activate advanced functions in software. There are fingerprint reader mice, which will only operate if the fingerprint of the user is accepted by the mouse as indicating an approved user. And most people now use wireless mice, which allow for greater freedom of movement, and also remote movement. There are “tactile” mice which vibrate when the user reaches a boundary or physical limit in gameware or software. Probably the most widely integrated recent change is the “optical” mouse which completely eliminated the tracking ball and instead projects a LED (light emitting diode) onto the tracking surface which bounces back and is picked up by a CMOS (complementary metal-oxide semiconductor) sensor. It basically takes thousands of “pictures” each second and as the resulting patterns change it translates the changes into motion and speed patterns. Makes of “optical” mice claim that they will last longer because the bottom is sealed so dust and oils cannot enter the mouse, and there are fewer moving parts to break.
Dig Deeper
Internet Connections
Recommended Reading
- How Computers Work by Ron White and Timothy Edward Downs (ISBN: 0789736136)
- How Computers Work: Processor and Main Memory by Roger Young (ISBN: 1403325820)
Writing Activity
Write an essay or a paragraph describing how engineering has changed another product over time. Choose from the following products: television, toaster, light bulb, automobile transmission.
Curriculum Alignment
Alignment to Curriculum Frameworks
Note: Lesson plans in this series are aligned to one or more of the following sets of standards:
- U.S. Science Education Standards (http://www.nap.edu/catalog.php?record_id=4962)
- U.S. Next Generation Science Standards (http://www.nextgenscience.org/)
- International Technology Education Association’s Standards for Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
- U.S. National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics (http://www.nctm.org/standards/content.aspx?id=16909)
- U.S. Common Core State Standards for Mathematics (http://www.corestandards.org/Math)
- Computer Science Teachers Association K-12 Computer Science Standards (http://csta.acm.org/Curriculum/sub/K12Standards.html)
National Science Education Standards Grades K-4 (ages 4-9)
CONTENT STANDARD E: Science and Technology
As a result of activities in grades K-4, all students should develop
- Abilities of technological design
- Understandings about science and technology
CONTENT STANDARD B: Physical Science
As a result of the activities, all students should develop an understanding of
- Properties of objects and materials
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a result of activities, all students should develop understanding of
- Risks and benefits
- Science and technology in society
CONTENT STANDARD G: History and Nature of Science
As a result of activities, all students should develop understanding of
- History of science
National Science Education Standards Grades 5-8 (ages 10-14)
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop an understanding of
- Motions and forces
- Transfer of energy
CONTENT STANDARD E: Science and Technology
As a result of activities in grades 5-8, all students should develop
- Abilities of technological design
- Understandings about science and technology
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a result of activities, all students should develop understanding of
- Risks and benefits
- Science and technology in society
CONTENT STANDARD G: History and Nature of Science
As a result of activities, all students should develop understanding of
- Nature of science
- History of science
National Science Education Standards Grades 9-12 (ages 14-18)
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop understanding of
- Motions and forces
- Interactions of energy and matter
CONTENT STANDARD E: Science and Technology
As a result of activities, all students should develop
- Abilities of technological design
- Understandings about science and technology
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a result of activities, all students should develop understanding of
- Science and technology in local, national, and global challenges
CONTENT STANDARD G: History and Nature of Science
As a result of activities, all students should develop understanding of
- Nature of scientific knowledge
- Historical perspectives
Standards for Technological Literacy – All Ages
The Nature of Technology
- Standard 1: Students will develop an understanding of the characteristics and scope of technology.
- Standard 3: Students will develop an understanding of the relationships among technologies and the connections between technology and other fields of study.
Technology and Society
- Standard 4: Students will develop an understanding of the cultural, social, economic, and political effects of technology.
- Standard 6: Students will develop an understanding of the role of society in the development and use of technology.
- Standard 7: Students will develop an understanding of the influence of technology on history.
Design
- Standard 8: Students will develop an understanding of the attributes of design.
- Standard 9: Students will develop an understanding of engineering design.
- Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.
Abilities for a Technological World
- Standard 13: Students will develop abilities to assess the impact of products and systems.
The Designed World
- Standard 17: Students will develop an understanding of and be able to select and use information and communication technologies.
Related Engineering Fields and Degrees
Student Worksheet
Dissect a Mouse – Component Parts
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Step One: As a team, disassemble either a new (inexpensive) or old unusable “track ball” mouse, using the materials provided to you. Be sure that the mouse is not connected to a computer and that no power is flowing through it. You will need to use a very small screwdriver, such as the type commonly found in eyeglass repair kits. Be careful as you pull the plastic cover off the mouse.
Step Two: Observe the mechanical parts that move when you move the roller ball. Also observe the two or three “switches” and see how they can click when the mouse case has been removed.
Questions:
- How many component parts did you find? List and describe them.
- What different types of materials (plastics, metals) were used in the construction of your mouse?
- Based on what you examined, what is the weakest design aspect of the “track ball” mouse? Why? (This might be an attribute that would make it difficult with a physical disability to use, or a perceived limitation of the design, such as the cord is too short).
- You are the inventors! How would you improve the design to eliminate or strengthen the part or operating feature you found in #3 above? Attach a drawing or sketch of your proposed component part, and answer the questions below:
What new materials will you need (if any) What materials or parts will you eliminate (if any) How will this new design address the shortcoming you identified? How do you think your new design will impact the cost of this mouse? Why? - Develop a model of the new working part of the mouse using simple classroom materials (glue, scissors, tape, ruler, paper, toothpicks, straws, spools).
- As a team, present your model and ideas to the class.
Translations
Industrial Engineering
Computer Engineering