Wednesday, May 4, 2016

bRyAn nah-jk-fam-this-is-it LiN Ambitious Science Article

The article outlines five qualities that make models useful in the classroom, and concedes that not all models are effective at engaging students in the scientific modeling process. Especially important was the idea that models should represent processes rather than "things," since "things" are easily found in textbooks and do not provide much room for further exploration and model manipulation. This ties into the fact that models should be revisable, the fifth quality that the article talks about. Another key takeaway from the article was the emphasis on the both the seen and the unseen, especially when looking at "invisible" things such as waves or atoms, and how guiding the students to look at unobservable factors can open new ideas.

Something I found to be important during this course that the article emphasized was the use of time and showing time passing in models. If you eliminate the time factor from a model, you often end up just looking at a "thing" rather than a process. Putting extra consideration into time and its effects on the individual processes of a model will allow students to really understand the causes of each event and its effects on other events as time passes.

Bryan I-swear-this-is-the-last-one Lin Harlow

Harlow et al. talks about the concept of "pedagogical resources," defined as "small, discrete ideas about teaching science that are applied appropriately or inappropriately in specific contexts" (Harlow et al., 2013). Harlow et al. references the three major problems in training preservice science teachers as originally proposed by Mikeska et al. in 2009: (1) engaging students in science, (2) organizing instruction and (3) understanding students' ideas. The most pressing difficulty, Harlow argues, is that science teachers must understand students' ideas in order to organize their instruction in the first place. This is especially relevant in our class discussions on the difficulty of implementing effective scaffolding in a lesson.

The first pedagogical resource that Harlow proposes is that the teacher's role is to provide the right answer. The Hestenes article discussed in class reinforces this idea that while many students can recite Newton's laws of motion, they do not know how to apply the laws correctly. NGSS also ties into this concept, agreeing that students should not be taught to memorize and regurgitate facts but rather to think scientifically.

Two points that Harlow et al. made was that teachers should learn content using the methods they will be using to teach and that models should be taught iteratively. This is something that is reflected in our class, as we learn to use the modeling software StarLogo Nova extensively. We are also given several scenarios in which to iteratively improve on our models little by little, and finally work on teaching the modeling process in the second half of the class after we've already mastered the learning ourselves.

An interesting concept emphasized by Harlow et al. is the idea that all the pedagogical resources can be helpful to students when applied appropriately, and that they are only negative when applied inappropriately in the classroom. This is something I would have liked to see more discussion of in the other readings for our class, especially pertaining to the first resource that the teacher's role is to provide the right answer. Part of the difficulty in implementing the correct amount of scaffolding also depends on when the teacher chooses to provide the "right answer" for certain concepts.

kobe BRYANt LIN Epistemic ADI

Aggregate behavior and system dynamics models can be used effectively to explore an ADI activity centered around osmosis and its role in establishing equilibrium across a semipermeable membrane. Aggregate behavior models can be used with modeling software such as SLNova and agent-based models can be constructed to look at the way a large array of individual particles produces an aggregate behavior for the entire system. System dynamics would also be effective for looking at a stable equilibrium across cell membranes, and how the concentration of solutes provides the mechanism for a feedback loop.

Students using aggregate behavior and system dynamics models can be provided with information on the way a cell membrane is formed. They will first be given an example of a feedback loop in a cell that goes to a stable equilibrium. Additional activites can be centered on asking why a cell needs this equilibrium to function. Students can be provided with a base model but also guided to construct additional models that allow them to adjust the concentrations across a membrane to observe osmosis in action. If time allows, students can also observe feedback loops in general and see what would happen if the equilibrium was unstable (i.e. a negative feedback loop vs. a positive feedback loop).


In the Biology EOC, Performance Indicator 3210.1.5: "Identify how enzymes control chemical reactions in the body" is used to create the following ADI.

Step 1: Identification of the Task

The ADI will be introduced by teaching students the basic structure and function of enzymes. Students should already understand the concept of pH and titration and know how to pipette properly. They should kmow how indicators work and how to use pH strips. There will also be a short lesson introducing the hydrolysis of starch to glucose that occurs in the mouth and the small intestine.

The problem: The enzyme amylase reacts with starch and facilitates the hydrolysis of starch into glucose, which is usable by the body. However, amylase is only active in the mouth and in the small intestine but not in the stomach. Why is amylase inactive in the stomach? What about the stomach is different from the mouth and small intestine?

Step 2: Generation of Data

Students will be broken into lab groups and each given two beakers, one with a neutral pH of 7.0 and another with a pH of 2.0. The beakers will have starch and IKI dissolved in solution, which stains starch blue-black. Originally, both beakers will be blue-black. The students will be instructed to take a pH test of both beakers and record this information. They will then dissolve amylase into each beaker and record what happens to the color. If the starch is hydrolyzed by the amylase into maltose and maltotriose, then the solution will no longer be blue-black as IKI does not stain these sugars. If the starch has not been hydrolyzed enough, the solution will remain the same blue-black color.

Step 3: The Production of a Tentative Argument

Students will get in groups and develop an argument for why they think amylase is inactive in the stomach but active in the mouth and small intestine.

Steps 4-8:

Students will be share their ideas and discuss them with other groups. They will be encouraged to research the mouth, stomach and small intestine in order to back up their arguments. They will be given a chance to revise their models based on the feedback of other groups and finally the entire class will discuss their findings together.

Bryan Lin VanLehn

The most effective modeling technique in VanLehn (2013) for students modeling the spread of the Zika virus is agent-based modeling, a paradigm explored in detail in this class. Agent-based modeling allows students to isolate the individual classes of agents in a system and program their behaviors, which is vital when each agent (humans, mosquitos at different life stages) has a wide range of behaviors. Also relevant to successful agent-based modeling in VanLehn is the use of virtual labs and virtual field studies. This allows students to manipulate the factors at play and visualize the effects of each agent on the system as a whole.

VanLehn also proposes scaffolding by decomposition into subsystems, an activity that would help students understand better. The life cycle of mosquitos should be modeled as a subsystem on its own, human interactions should be modeled as a subsystem to see which behaviors cause the spread of Zika and mosquito interactions with humans should be modeled to see which interactions result in the spread of Zika either from mosquito to human or human to mosquito.

Another form of scaffolding in VanLehn that be effectively applied to modeling Zika is the "meta-tutoring" through the use of Betty's Brain. Betty's Brain can work by asking students guiding questions, but more importantly can force students to ask explorative questions of their own in order to fully test their models. However, VanLehn notes that it is quite difficult to get students to ask substantive questions beyond verifying answers, a problem that should be explored further.

Bryan Lin Hestenes Article

Many of the 8 NGSS practices are reflected in the Hestenes article, especially as Hestenes heavily emphasizes the use of models in teaching scientific concepts. Hestenes also agrees with the NGSS that students should be taught how to think scientifically rather than simply memorize facts, stating "The great majority of such students can state Newton's laws [of motion]...[but] they cannot consistently apply the laws correctly" (Hestenes, p. 742). He further states that teachers should be moderators of discussion rather than sources of information. Hestenes rejects positivism and advocates for constructivistic epistemology, which proposes that "physical concepts are free creations of the human mind" and "meaning is constructed and matching with experience" (Hestenes, p. 735), supporting the first NGSS practice of Asking Questions and Defining Problems.

One NGSS practice that Hestenes fails to address completely is Using Mathematics and Computational Thinking. Hestenes, as a theoretical physicist, quite obviously support the use of mathematics as a tool in exploring the world, claiming that Newton's greatest achievement would not have been possible without his understanding of mathematics. However, Hestenes fails to address the possible adoption of computers as a powerful tool for developing a scientific mindset. While PCs such as the IBM 5150 and the original Apple Macintosh existed during the time of publication, they came with quite a hefty price tag. The lack of easy access to computers, especially for students, no doubt contributed to Hestenes' failure to address the potential for computers in science education.

Bryan Lin Collins Zika Models