II Creative Reasoning Processes to Support Identifying a Pattern to be Explained

Example 1: Ask students to recall earlier observations

Teacher: You know that we can swallow through our mouth and breathe through our mouth or nose. How is the inside of our throat made so that we can do that?

Example 2: Ask students to make a prediction and test it

An example to begin a unit on energy in the human body at the elementary level could be to ask students to predict the direction of changes in breathing and heart rates when doing calisthenics. Then have them actually do calisthenics and measure their breathing and heart rate. Later this data could be recalled and used to motivate the development of models of the pulmonary and circulatory systems that explain why the rates increased.  

Example 3: Ask students to collect observations

In a high school electricity unit, the target model was that of a series circuit in which the “rate of charge flow” (current) was uniform throughout. Early in the unit, students were asked to observe the effects of adding a second mini light bulb in series with an existing single bulb. In addition to noticing that the brightness of each of the two bulbs was less than the brightness of the original single bulb, students also placed magnetic compasses under the wires of the circuit and observed that the magnitude of the needle deflection was less than when there was just one bulb. Students were often surprised to see that the needle deflection (and thus the current) was the same at various locations throughout the circuit since many made the assumption that current would be greater “before” the bulbs than “after” them.

This activity resulted in a discrepant event, where the outcome was not what many students expected. The activity was designed to address known student misconceptions about electrical current. Such observations of unexpected results can lead to very dynamic classroom discussions and innovative student reasoning as students dig for an explanation.

Batteries and bulbs set up for each small group. A compass was taped into position and the students moved the circuit around over it. They placed some part of the wire over the compass, then closed the circuit and observed the deflection of the compass needle that resulted. This process was repeated to test different parts of the wire. The students were surprised to see that the magnitude of the deflection was the same at any point in the wire, whether “ before,” “after,” or between the bulbs. (CASTLE curriculum, Figure 1.2a)

Example 4: Ask students to collect observations

The teacher was going to teach diffusion but first, she asked the students to place an egg inside of vinegar to remove the shell and the egg was full of vinegar. By the next day they put the eggless shell on top of green corn syrup. The next day they observed that the was on top of the corn syrup deflated and they could observe the yolk through the membrane. The also observed that the corn syrup smell like vinegar. The teacher asked the students the following question: Can you come up with an explanation for why the vinegar came out????

Example 5: Use a demonstration and have the class make observations

The teacher opened a bottle of ammonia and had students raise their hands when they smelled it. The pattern of hands being raised from nearer the bottle to farther from the bottle was a pattern for them to explain.

Example 6

T: What is it that causes gravity, anyway?

Many students have the general idea that “Everything pulls on everything else,” but don’t believe that the forces between, say, a ping pong ball and the Earth are equal and opposite. To arrive at this understanding, a unit in Preconceptions in Mechanics helps students move from the “Everything pulls on everything else” model to a more sophisticated model of “masslets” that can help them begin to reason about gravitational forces at a new level of detail.

Example 7

T: We have learned that pushing a plunger into an air syringe will cause an increase in pressure in the air inside it, and that the air ‘acts like a spring’ to push back on the plunger. But how does that happen? What causes the increase in pressure?

In this instance, students already have a macroscopic model of the phenomenon explained by the "spring-like air-pressure" model. Here the teacher takes that macroscopic idea as a pattern to be explained by asking students to explain what causes the pressure. Asking them to develop a microscopic model of pressure that involves collisions from gas molecules against the plunger is asking for a new and deeper level of explanation.