Lesson 3. Lesson 3 - Detecting Change

Umit Aslan, Umit Aslan, Royi Lachmy, Umit Aslan
Chemistry
120 min
Introductory High School Chemistry
v1

Overview

In this activity, teacher demonstrates how virtual detectors can be added to the students' models. Students plan what type of sensors to deploy in their model and deploy these sensors in the sandbox model they created in the previous activity. As they test their model, they should revise their sensor designs and/or model conditions to either 1) better align with the behavior of the odor diffusion phenomena experienced as a class or 2) to provide stronger evidence for the causes of state changes and fluctuations in the detector reading in their model. Students rewrite their previous scientific explanation to include the new evidence from their virtual detector measurements. Students will eventually present their findings to the class.

Standards

Computational Thinking in STEM
  • Computational Problem Solving Practices
    • Developing Modular Computational Solutions

Acknowledgement

Cite the Modelsim research

Activities

  • 1. Review
  • 2. Plan Your Investigation
  • 3. Exploration 1 - Adding Sensors
  • 4. Exploration 1 - Procedure 2 - Conducting Your Experiment

Student Directions and Resources


In the previous activity you planned and carried out an experiment concerning the diffusion of gases. To collect data, you used sensors that we provided you. In today's activity you will attempt to quantify the results of your experiment by programming sensors into your sandbox model.

 

The big question: How can sensors help me analyze patterns of change?

 

 

 

 

1. Review


In the previous activity, you wrote a scientific explanation to the topic and focus question that you are examining with your experimentation in the model. Now, work with another classmate to refine your explanation from before, using the criteria below to guide you. 

 

Claim

  • The claim answers the question in one sentence.

Evidence

  • Data from the classroom experiment is included.
  • Data from the computer model is included.
  • What the data means is explained.

Reasoning

  • One or more scientific principles are included.
  • Why the scientific principles are relevant is explained.
  • The entire explanation is coherent; the reasoning is connected to the claim and the evidence.

Question 1.1

What was your question? (You can copy from Lesson 2)



Question 1.2

What was your explanation? (You can copy from Lesson 2)



Question 1.3

What is your refined answer after you working with another student? 

2. Plan Your Investigation


To strengthen your claim and to understand gas particle behavior further you will be able to add detectors to your computer model. You will be able to design the detectors that you will be using ,as well. What kind of data would be most useful for the detectors to report? Some examples are:

  • How long it takes before a particle reaches the detector? 
  • What is the average number of particles that have been at the detector since it was first turned on?
  • What is the concentration of particles near the detector?
  • Are there any particles near the detector?
  • Which direction are particles traveling when they pass the detector?
  • What is the temperature of the gas (average speed of the particles) at the detector?

Question 2.1

What do you think would be useful data for the sensor(s) to report?

3. Exploration 1 - Adding Sensors


Below is the sensors sandbox model you were introduced to yesterday. You can also see your research question from the previous step right below the model.

  1. Press SETUP. This gets the model ready for you to interact with it and then run. 
  2. Click LOAD MODEL button and load your model from yesterday by choosing the file you saved.
  3. Press GO/STOP/ADD ELEMENTS to run the model.
  4. Try to add sensors to your model. 

 

Note: In this step, just focus on making sense of which sensors you have, how do they work, and what you can do with them . Do not try change the sensor code yet.

 


Question 3.1

There are four types of detectors. What is the maximum number of detectors you can add of each type?



Question 3.2

If you wanted every type of detector to detect the same way, what do you need to do?



Question 3.3

If you wanted to use two different types of detectors, each of which detects differently what would you need to do?



Question 3.4

How can you change the detector code so that it detects more than one color of particle?



Question 3.5

What type of pattern(s) will you program your sensors to identify to help you see data more clearly (you may check more than one)?

  Patterns related to stables states    
  Patterns related to fluctuations over time    
  Patterns related to similarities between different detectors
  Patterns related to variance between different detectors    
  Patterns that are similar to those we found in our peppermint data


4. Exploration 1 - Procedure 2 - Conducting Your Experiment


In this last step, you will modify the code of the sensors to identify patterns in your model.

  1. Load your saved world, using one of the LOAD button at the bottom left of the sandbox window.
  2. Change the sensor code from the windows CODE 1, CODE 2, CODE 3, and CODE 4 to create the type of sensor behavior(s) you want.
  3. Press GO/PAUSE/ADD ELEMENTS to run the model.
  4. Set the MOUSE-INTERACTION chooser to add/move sensors. And add sensors or move the ones you have added using your mouse.
  5. While you are working you may choose to save your world periodically using the SAVE button so that you do not risk losing your progress .

 

Note: Do not change the code of the EXAMPLE 1, EXAMPLE 2, EXAMPLE 3, or EXAMPLE 4 windows. These codes are provided to you so that you can copy them and paste them to the code windows in case you want to reset the code of a sensor or try a new code.

 

 

Next, test your model to see how the particles move in it by turning the MOUSE-INTERACTION chooser to "none - let particles move"

  1. Record the results in the following questions. Because some particle interactions involve randomness, it's important that you run your experiment more than one times.
  2. When you've collected your data, you may want to average some measurement values that changed over the course of many runs. For example, if you ran the model three times with the same starting conditions, you might want to average the value of your dependent variable (pressure, time, etc) over those runs.

Repeat any of these steps until the sensor data either:

  • helps you discover interesting patterns in the data.
  • provides you additional evidence for your scientific explanation from the previous activity.
  • helps you understand important mechanisms at work that explain cause some (or all) of the patterns in the data.

Record the relevant data from the model run that you intend to use in the following step.

If you want to use the world you have set up or changed in this step with more sensors in the next step, save your world for future usage. 


Question 4.1

In the table below, record any important data made or calculated during model runs in the sandbox model. (Could be better as a file upload of an excel file containing behavior space data).



Question 4.2

In the space below, record any observations made during model runs in the sandbox model.



Question 4.3

What interesting patterns did you discover in the data, what additional evidence for your scientific explanation do you now have, and/or what important mechanisms are at work that could explain some (or all) of the patterns in the data?



Question 4.4

(Re)write a full scientific explanation using your outline from your previous investigation and your data from this investigation to guide your writing. Be prepared to present your explanation to your class.