Category Archives: B. T-GEM

For a moment, imagine a 1-m pendulum with a 500g bob on one end.  The pendulum is given an initial starting angle of 20°.  Which of the following actions will increase or decrease the period of the pendulum swing?

1. Shortening or lengthening the length of the pendulum
2. Decreasing or increasing the mass of the bob
3. Increasing or decreasing the starting angle by 10°.

This is one of my favourite questions to ask a class of Physics 11 students in order to introduce pendular motion.  While usually all students are familiar with pendulums, few have ever taken the time to evaluate how length, mass and starting angle affect its period.  

In this lesson plan below, the teacher addresses pendular using a 3 step T-GEM cycle with their class:

Step 1: Background content information

Class discussion and traditional notes:

What is a pendulum?  What are some examples?

How do they work?
What are the parts of a pendulum?
What is the period of a pendulum?
What is the frequency of a pendulum?
What variables affect a pendulum’s period?

• Length of the pendulum
• Starting angle of the pendulum
• Mass of the bob
• Force of gravity

Step 2: Generate

Students are asked to predict the relationship between a pendulum’s period and the mass of the bob.  As the mass increases, what happens to the period?  Think-Pair-Share: Students have 30 seconds to arrive a conclusion, share with a partner, followed by a short class discussion.  

The teacher uses a real pendulum and students are asked to measure the time it takes the lighter and heavier bob to complete 10 cycles with their phones.  Students arrive at the conclusion that the mass of the pendulum has no effect on the period of the pendulum.

Step 3: Evaluate

Students are asked to work in table groups to investigate: Why does the mass of the bob not affect the period of the pendulum?

Students will use pendulums at their table to arrive at their conclusion.   Groups will then share out their understanding.

Students are asked to explore other variables that may have an effect on the period of a pendulum.  Students will begin to notice that the length of the pendulum has an effect on the period.

Step 4: Modify

Students are asked to work in table groups to investigate: What is the relationship between length and period?  (Linear, quadratic, exponential, logarithmic or other?)

Students run several tests in the following pendulum simulation to eliminate confounding variables.  Students are asked to summarize the relationship by generating an equation that might describe the effect length has on period.

Step 5: Generate

Students are asked to predict the relationship between a pendulum and the gravitational field strength (g).  How would the period change if the pendulum was brought to the moon?

The process repeats through a second GEM cycle.

Simulation

https://phet.colorado.edu/sims/html/pendulum-lab/latest/pendulum-lab_en.html 

References

Khan, S. (2010). New pedagogies for teaching with computer simulations. Journal of Science Education and Technology, 20(3), 215-232.

In our Bachelor course on classification systems, I introduce the idea behind classification systems and also present the topic of “semantic inconsistency”. I know from the exams in this module that this is an issue that the student seldom fully understand, even when I try to explain this in class quite well. So here is my idea of using GEM:

Within the module, students first get an introduction into the idea of classification system. Classification systems allow to clearly assigning an item to a class (e.g. a very good presentation is assigned the mark “A+”). This assignment must be fully clear, to avoid misclassifications. Classification system that allow this are called “semantic consistent”, the others “semantic inconsistent”.

To further work on this concept, I will present a short instruction into ICD10 – the 10^th edition of the International Classification of Diseases. I will introduce the ICD10 browser at http://apps.who.int/classifications/icd10/browse/2016/en.

Then let’s start with GEM:

Step 1: Generate

Compile information:

• Students are asked to work a bit with the ICD10 tool, to get familiar on how it works.
• Students then get a list of 10 – 20 simple diagnosis that they are asked to code. They are asked to compare their findings with their neighbor. Examples:
  • Angina pectoris -> Code: I20.0
  • Acute sinusitis -> Code: J01
  • Alcoholic liver disease -> Code: K70
  • Atopic dermatitis -> Code: L20

Generate relationships:

• Based on these examples, students are asked to explain how ICD10 is organized: What is the organizing principle?
  • Students will find out that ICD is (mostly) organized according to organ system (nervous system, eyes, circulatory system, respiratory system, digestive system etc.)
  • Students will be asked to find some proof of this assumption by showing some codes related to organ systems.

Step 2: Evaluate

• Students are asked to code a list of further diagnosis such as:
  1. liver cancer
  2. viral hepatitis
  3. respiratory tuberculosis
• Students are asked what is happening here, what is wrong?
  • They will find out that these diagnosis are not only coded according to organ system, but on different axes
    • liver cancer -> Code: C22.9 (Axe: Neoplasm)
    • respiratory tuberculosis -> Code: A15 (Axe: Infectious diseases)
  • Students are asked to find more such examples of codes not organized according to organ system

Step 3: Modify

• Students are asked to explain why this can happen
  • They will find out that ICD10 axes are related to different perspective of coding (“organ system” versus “type of disease”)
• Students as asked to look again at the ICD: So what is the organizing principle?
  • It is a mix of organ system and type of disease
• Students are asked what this means for the coding person
  • They will find out that indeed such a diagnosis could be coded in two area (viral hepatitis may be coded either as liver disease or as infectious disease)
• Students are asked to discuss with their neighbor how this problem be solved
  • They may come up with the idea that coding rules are needed
• Students are asked to find out how ICD solves the problem
  • They will find out that indeed ICD includes rules, named “exclusion/inclusion” that clear point to one axe
  • For example: Viral hepatitis is not coded as liver disease, but as infectious disease

Okay, this is quite a complex example, but we are at the bachelor level here, so I guess this could work out. In any case, it is worth a try – I have this module in March, so I will try this exercise.

Do you think the approach could work?

Elske