Introduction chapter one. The features of linking activities

CHAPTER TWO. LINKING ACTIVITIES WITHIN A LESSON
2.1.Lesson plan on links and guiding controls
Instructional goals: Students will be able to: (1) Understand the mechanical function of linking, (2) Explain why links and guiding controls are used, (3) Explain characteristics of different links, and (4) Identify four characteristics of a variety of links used in everyday objects, (5) Identify types of guiding controls in everyday objects.
Grade level: Grade 7, 8
Duration: 75-150 minutes
Instructional Materials: Baskets of household items or items used at school or in a science lab or items is student pencil case or clothes⁴. Please find sample materials in the description of the Activity Option activity section.
Worksheets: Appendix A. Also, teachers in Quebec can refer to the Eureka Teacher Guide B U2 p. 53 & EN 40
QEP POLs for secondary cycle 1 relevant to the concept of links:
1. Describes the role of links and guiding controls in a technical object
2. Identifies a guiding control in a technical object, as well as the related links (e.g. a pizza wheel is guided by a pivot, which links it to the handle)
Children’s preconceptions relevant to the concept of motion transmission and motion transformation systems
1. Students tend to confuse the vocabulary used in links. For instance, students confuse some direct/indirect links. A light bulb screws into the socket, but there is no third component providing a link BUT if a coat hook is held to the wall with a screw, then the link is indirect since the screw in this case is a third component.
2. Students may find it difficult to conceptualize differences between links and guiding controls because guiding controls function both to guide movement, and they are also links. An example is a screw, or the lid on a glue stick: they are both links and guiding controls.
3. Some students have difficulty distinguishing the difference between rotational and helical guiding.
Description of the Lesson
The goal of this activity is for students to (1) correctly use the terminology associated with links, (2) to correctly identify different links when examining an object, and (3) understand and identify the three types of guiding controls. This lesson plan includes the following steps:
Step 1: Eliciting Student Thinking/Intuitive Models: In this step, teacher can choose from one of the activities (i.e., Activity Option #1 – Background Knowledge Probes (BKPs) or Activity Option #2 – Let’s categorize the links!), in order to help students make the topic of links relevant to their daily life.
Step 2: Collecting and Making Sense of Data: This step follows the previous Activity Option #2 – Let’s categorize the links! In this step, the teacher starts a class discussion on how groups labelled the links they looked at in their objects, and collect students’ reporting data on the board.
Step 3: Developing Evidence-Based Explanations: Following a class discussion on categorizing links (included below), the teacher engages in this step by introducing an activity using links in sports equipment, Links and Guiding Controls in Sports Equipment, to consolidate students’ understandings of the mechanical function of links and guiding controls. Students then participate in a gallery walk where they go around the class and discuss the sports equipment analysis made by other groups in the classroom.
Step 4: Evaluation: Teacher can assess students’ learning outcomes by inviting students to write reflective journals on links found in common everyday activities.
Details and procedures of each step in the lesson plan are explained as follow:
Step 1 of the Lesson: Eliciting Student Thinking/Intuitive Models
In this step, teacher can choose from one of the activities (i.e., Activity Option #1 – Background Knowledge Probes (BKPs) or Activity Option #2 – Let’s categorize the links!), in order to help students make the topic of motion transmission and motion transformation relevant to their daily life.
In order for students to understand the importance of learning about links and guiding controls, begin the lesson by asking students what they see in their life that involves links. For example, teacher can say:
Before we start, I want you to think about if you have seen any technology (or anything) in the classroom today that involves objects held together, such as objects in your pencil case, or in your notebooks, or on your clothes etc. How can you describe the ways the parts of the object are held together?”
“We are going to start learning about what holds parts of an object together, and what controls the motion of moving parts.⁵.” Can you think of any household objects that moves in circles? What about objects that move up and down? Or back and forth? Let’s think about objects where parts are held together. What do you use if you have dry lips? What holds the pieces together? How do the parts move with each other?
Note: At this point the teacher should not introduce the scientific terms, such as rotational, translational, or helical guiding, nor the vocabulary about different linking characteristics because the intent is to elicit students’ intuitive ideas about links and guiding controls found in different objects. 
Ø Recording students’ ideas: The teacher can write down students’ responses on a board or chart paper or teachers can re-voice students’ responses to summarize what the students are saying in different ways.
Ø Orienting students to each other's’ thinking. The teacher can re-voice students’ responses and connect the students’ response to the idea of motion transmission and transformation.
Then, the teacher can introduce this lesson by saying: “As you mentioned, there are lots of things in our life that involve holding objects together, and about controlling motion. However, there are different mechanisms that these motions work. In today’s lesson, we are going to learn about how things are held together, and how motions are guided in the technologies we see in our daily life.” After introducing the topic, the teacher can choose one or both of the following activities (i.e., Activity Option 1: Background Knowledge Probes (BKPs) or Activity option #2: Let’s categorize the links!) to further explore students’ prior knowledge related to links and guiding controls.

Activity Option #1 – Background Knowledge Probes (BKPs) Guiding Controls

Part 1: In order to identify to students’ prior knowledge, skills, attitudes, experience and motivation, the teacher can ask the following question: Question 1. What type of movement is done by the blades of the scissors when cutting a piece of paper? A. Rotation B. Translation C. Helical Question 2. A bicycle is rolling in a straight line down the street. What type of movement best describes the movement of the bicycle’s frame? A. Rotation B. Translation C. Helical Question 3. What type of movement is carried out by a screw when it is inserted in a wooden board? A. Rotation B. Translation C. Helical Question 4. Which situation is an example of rotational motion? I- A child on a toboggan sliding down a hill. II- A child swinging on a swing. III- A child riding a Ferris Wheel.​ a. I only b. II only c. III only d. I The teacher can use clickers to obtain students’ responses. If the school does not have clickers, teachers can ask questions of the whole class. Students can raise their hands. If there is no answer from students, teachers can also ask them to write their answers on a piece of paper and put them in a box. The teacher will then write some responses on the board (or a chart paper) for discussion. Part 2: Pressing for explanations: After presenting and discussing students’ answers with them, ask students to talk about their reasoning, explaining their responses either in small groups or in a whole class discussion. Sample guiding questions are: We see that many of you chose option C as an answer. Would anybody want to share why they chose letter C? Summarize why you chose letter C. Note: The teacher may re-voice their explanations and write their responses on the board. The teacher then introduces the terms “links” and “guiding controls”. Then, the teacher can further probe students’ understanding by asking them to think about the characteristics of different links, and the difference between translational, rotational and helical motion in objects being guided.

Activity Option #2 – Let’s categorize the links!

Activity Option #2 follows the introduction and discussion of the concepts, links. The goal of this activity, titled Let’s categorize the links! is to have students: (1) use the vocabulary associated with links as they observe linked (2) to have students to observe the different types of guiding controls. The activity has two parts: