Introduction
Student A says that “heat makes an ice cube turn into liquid water”; student B states that “while heating an ice cube, water molecules are moving faster and they break the hydrogen bonds between molecules and eventually these molecules separate, thus forming liquid water.”
Background
Computer-Based Modeling
Reasoning Mechanistically with Stop-Motion Animation
Method
Study Context
Modeling Tasks and Data Collection
Data Sources and Analysis
Mechanistic aspect | Example of students’ excerpts |
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1. Target Phenomenon (TP) We code the presence of this element in students’ utterances when the students describe a particular phenomenon without explaining how and why this phenomenon occurs | Concrete: “The ball goes up with a straight forward line” Abstract: “As the ball goes up, its energy is getting less” |
2. Setup Condition (SC) We code the students’ statements as the setup condition when the students describe a starting condition that must happen before the particular event runs | Concrete: “He kicks it with a sort of upward angle (in the first position)” this statement presents the way a football player kicks the ball in the first position to enable the ball to move up in a certain direction Abstract: “When the foot is kicking the ball, it is transferring energy to the ball, and then this energy is used for the ball to go up” This statement explains the way energy comes up, before the ball uses this energy to move up |
3. Entity (E) An entity is a causal agent that plays a crucial role in producing a phenomenon. We code for the presence of this element in the students’ statements when they try to identify the agents that cause the phenomenon to happen. Those agents that are tangible or visible are classified as concrete concepts, whereas abstract agents are invisble or theoretical | Concrete entity: the foot, the earth Abstract entity: energy, gravity |
4. Activity of entity (AI) An activity is what entities engage in to produce a phenomenon. We code the students’ statements as this aspect when the students identify what entities do to give rise to a phenomenon | Concrete activity: “The foot kicks the ball” Activity is “kick the ball,” and Entity is “the foot” Abstract activity: “The foot gives force to the ball” Activity is “gives force,” and Entity is “the foot” |
5. Property of Entity (PE) An entity has a general property. By having this property, the entity could do a specific activity. We code students’ statement as property when the students identify any characteristic of an entity that is necessary for a certain activity | Concrete property: Air resistance is something that can be touched (property), so that “…because it needs to push all the particles of air out of your way” Abstract property: “it (the ball) still has forward momentum (property)” |
6. Organization of entity and activity (IOE) For a phenomenon to happen sometimes requires a specific condition: spatial organization of entities or temporal organization of activities. We code the students’ statements as this aspect when they describe where entities are located (spatial) or how long entities do the activities (temporal) | Concrete: “The ball has only kinetic energy, when the ball is on the ground” Abstract “The ball can go up as long as the energy is stronger than gravity” |
7. Chaining (C) We marked the students’ statements with chaining when their explanations present a cause-effect relationship. This relationship signifies a claim about what must have happened previously to bring about the current state of things (backward-chaining) or what will happen next given that certain entities and activities are present (forward-chaining). In this study, all students’ chaining is classified as forward-chaining. Also, when students construct a chaining, they involve not only entities and activities but also other elements of mechanistic reasoning. For example, a chaining consists of entities, activities, and a setup condition Because the students employ forward-chaining, their statements referring to the next condition are used to determine whether chaining is classified as concrete or abstract concepts. For example, “the ball goes up in a straight line, because you kick it with sort of an angle,” the chaining is “the ball goes up in a straight line” and this chaining is concrete | Concrete: “Because you kick the ball up, so the ball goes up in a straight line” Abstract: “As the ball goes up (with a change in the direction), it loses momentum.” |
Results
Model of the Ball Motion
Phase | Characteristics | Example of quote |
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Phase A | This phase is the initial movement of the ball. The motion immediately after the ball is kicked. This movement is only influenced by the kicking. There is no effect of gravity on this movement. Some students argued that as the ball goes up, the slope is constant | Concrete concepts: “so you kick it, and it goes there (to the second position in straight line)” Abstract concepts: “the person who is kicking the ball, he is giving like the force to the ball [from the bottom], that makes the ball go higher (in straight line)” |
Phase B | This phase is indicated by a change in the slope or the ball starts to change its direction as it goes up. This movement takes place from the moment the slope changes until the ball reaches the highest position. There is an effect of gravity on this movement | Concrete concepts: “when it (the ball) is on here (4th position), and then it starts decreasing (goes up with a change in direction)” Abstract concepts: “yes, because the gravity is like starting to. Because the force that is applied makes the ball goes higher, and then gravity makes the ball, like pull back to the ground, so it is here (moves up with a change in direction)” |
Phase C | This phase happens when the ball starts going down from the top position until it reaches the ground | Concrete concepts: “this point, at the highest point, it is up all the way, and then it is still in arch in going down (move down with curved line)” Abstract concepts: “because the gravity starts, hmm like, the force applied doesn’t enough to continue to go higher, and the gravity starts pulling the object [the ball] back to the ground [goes down from the top]” |
Mechanistic Reasoning as Demonstrated in the Reasoning about the Animations
Phase A
“… because the force is from the bottom [2nd frame; 1st position] … the person who is kicking the ball, he [the foot] is giving like the force to the ball [Frame 1 and Frame 2], that makes the ball [to] go higher [Frame 3] … The foot is kicking the ball like here, from the bottom [she draws a yellow arrow to represent an elevation angle; see Fig. 3] which makes the ball [to] go to this position [the second position, she draws a second yellow arrow, which links the first position to the second position, to represent the ball moving up in a straight line]…”.
“… because, I can see here [frame 1 and 2], that he kicks it with sort of upward angle, so I see sort of arch, forming… so you kick it [the ball], with sort of the angle [he points to a way of a kick representing the way the foot kicks the ball, namely an elevation angle], that makes it go that way [he draws a red line to represent the ball moving up to the second position in a straight line]…”.×
Phase B
“… after a certain time on air [in the second position; Frame 3], the ball starts to lose its momentum. And that [losing momentum] causes it [the ball] to slow down and a decrease in it [momentum]. hmm by slowing down, it [the ball] doesn’t increase as much with its height [he draws a blue line to represent the ball which was moving up in straight line and then its direction changed]… when right from the kick off [Frame 1 and 2], it [the ball] will have a momentum, and it [momentum] will be lost, due to air resistance and gravity trying to pull it [the ball] back down. Since it [the ball] has to go, since it [the ball] is going up [frame 3 to frame 4], it [the ball] slows down, because it needs to push all the particles of air out of your way and also needs to fight the gravity which is very powerful of force…”.
Phase C
“…because … the gravity starts pulling the object [the ball] back to the ground [from the top position] … the ball gets faster, which increases its kinetic energy. Also, potential energy decreases ….”.
“ … so then it [the ball] reaches a peak [the top position; Frame 6], … and then falling … because now it [the ball] is working with gravity … because this [gravity] wants to pull it [the ball] down [he points to the red arrow representing the work of gravity pulling the ball down; Frame 6, 7, and 8]. But it [the ball] still has forward momentum … It [the ball] can’t go forward straight, because it [the ball] still has to fight gravity, but it [the ball] is working with gravity, but it [the ball] still has some residual forward momentum. so when you do with that, it is sort of slope down, and angle [the ball moves down gradually], instead of dropping down immediately [he gestures to each position to depict the gradual downward movement] …”.