Part 3 Model Observation and Decoding


I left off the link for my Model Observation Form


This section of code colors our “world”. These humongous but fast-moving turtles cover so much ground so fast that our background appears color-blocked.



  2. The chunk of code that I looked at was setting up the terrain and what happens when the turtle hits the edge of the terrain. The code is saying that if the turtle hits the edge of the terrain it is supposed to be in, it makes a 180 degree turn and moves forward again.

  3. Mystery models are a great way to get our students thinking deeper. It makes our students use creativity and problem solving skills.


A little unorthodox. I know.

  2. This chunk of code is setting up what happens if a turtle hits an edge of the terrain or zone it is in. It does a 180 degree turn and moves forward again.
  3. Mystery models allows our students to use their creativity and critical thinking skills. They help our students how to problem-solve, not give up when it gets difficult, and use collaboration skills to solve a problem.


Here is the form for the mystery model. Our group felt it fit a predator/prey model in several of different habitats.

We decoded the code from mystery decoded

  2. When turtles reach the edge of their territory, they turn 180 degrees and proceed back.
  3. Mystery models help students develop critical thinking, problem solving and real world analytical skills.

  1. Link to Google Doc:

  2. Code Chunk:

3.This is the section of code that decreases the infection time (lifespan) of the magenta particles each time through the loop and then deletes them when the infection time reaches zero. I think this also causes some confusion in the model because when black particles are infected and turned magenta, the code never assigns them an infection time so they are immediately deleted the next time through the loop.

  1. I think the mystery model is a good way to get students to practice making observations and hypotheses or claims. The decoding part is a good way to review or teach coding concepts. Assigning students to fix some of the problems with the model would allow them to work on their coding skills and deepen their understanding of the model.


  2. This code explains that after the turtle is placed in a color, it has to stay in the color. If it hits a different color it does a 180 turn.

  3. I am going to use this after the kids do Module one as a refresher before doing an Adaptations lab.


This code means that if an agent in one color of territory runs into a color that is not the same as its own territory then the agent will make a 180 turn. This keeps the agent moving only in its territory of origin and does not allow the agent to move into a new territory.

I will use Mystery Models in my own classroom to deepen students’ understanding of how we can use computer models to simulate a disease outbreak. I can also use the lesson to focus on computer science skills involved with coding as we decode the code.


The Procedure stamps the territories that contain the turtles.
I put my screenshot onto the bottom of the doc because my computer did not want to past it here.


added my screen shot and coding into my drive document



I chose the segment of the code where the turtles turned colors when infected. To me that is the part that will capture the highest student interest and lead them to want to manipulate the model to modify, speed up, slow down, etc. the rate of infection. Hopefully would encourage them to take off from there for further investigations as well.


  1. Upon touching the purple agents the other agents will immediately change colors to black.The infection time is equal or less than zero and that is why the change color so quickly.
  2. I think this is a great lesson to help students think logically. The process of changing the widgets and understanding how they changed the interactions of the agents was very helpful to help me think logically.


  2. In words this means:
    -When a turtle collides, if the color of the collidee is magenta, keep as magenta.
    -Make 100 turtles, the “??” slider value will indicate how many magenta turtles to make.

    1. Mystery Models and decoding in my classroom would give students the ability to look at the “coding” process in a different way. Instructing them to “write out the code” helps to communicate their level of understanding of their knowledge of the coding blocks.

  2. This chunk is creating the part of the world that exists after the setup tab is clicked. It zero’s out all of the counters and sets up the location and colors of the agents based on the slider values.
  3. I can use this in my class as an exploration and critical thinking piece. It is great for students to observe first what is going on in a model. I will probably use the observation sheet provided and follow the lesson the way it was presented her. I may assign the section of code to be decoded based on what we have focused on in class.



  1. I chose the collision of the turtle. When the magenta turtle hits another if it is a high percentage (100), it will turn the other agent to magenta. I believe that this part of the code, is how the turtles “infect” other agents and that if the random percentage rate is low, that is why the purples all disappear.
  2. I like that students have to use higher level thinking to figure out what is happening. I like that it’s called a mystery. I also like that students will fail and that is part of the learning.

  2. The chunk of code shows says that if the black turtles collide with the magenta turtles, they will become magenta as well.
  3. This mystery model can be used as a whole group investigation or as a pair programming investigation with students developing ideas, predictions, and hypotheses just as I did. It could also be used as a simulation for how different things work in some of the units.