Thursday, March 15, 2018

Using models as part of the instructional process: What teachers need to know


 Rolando M. Tan

Using three-dimensional models in teaching has become part of the instructional practices of science teachers. Using models in teaching has shown marked improvements in students’ understanding especially of complex subject matters in science (Mclaurin, Halverson and Boyce, 2014). Models, which serve as a representation of the abstract concepts, help students construct ideas (Krontiris-Litowitz, 2003; Orgill and Thomas, 2006). Glynn (1991) states that using models that facilitate analogical reasoning is an effective way to foster understanding by relating their existing knowledge with text knowledge. This is an important consideration because effective analogies do not only motivate students but also help them clarify their thinking and avoid misconceptions (Orgill and Thomas, 2006). Moreover, analogies also “enhance student learning through a constructivist pathway” (Harrison and Treagust, 1993, p. 1292). If the research lesson would use such physical manipulatives or any other instructional models as part of the instructional process, lesson study practitioners and the so-called knowledgeable other must bear in mind the theoretical foundations of using teaching materials that foster analogical reasoning.
 
So what makes a model an effective teaching material to foster analogical reasoning? Gentner (1998) enumerates the processes in analogical reasoning: (1)retrieval – an individual tries to recover a previous analogous example from long term memory (2) mapping – examining the commonalities from two working memories and making inferences from one working memory to another (3) evaluation - where the inferences and their analogies are assessed and (4) abstraction – examining the common structure between two analogies. Gentner, focuses more on mapping as he proposes the Structure mapping theory for analogy. In structure-mapping theory, analogy is “a  mapping of knowledge from one domain (base) to another (target) which conveys that a system of relations known to hold in the base also holds in the target.”(Falkenhainer, Forbus, Gentner, 1989, p. 2).

Gentner (1983) stressed that mapping commonalities between the target domain (the object to be compared) and the base domain (the object which the target is compared to) would involve two aspects: object attributes and relational predicates. For example when the atom is compared to a solar system, the atom is the target domain while the solar system is the base domain.

Object attributes are the physical features that can be visibly seen on the base and on the target while relational predicates pertain to the interaction of the objects in a domain.  Structure-mapping theory  states that when several overlaps are found in the object attributes and in relational predicates between the target and the base, literal similarity is attained and if overlaps are strongly seen on relational predicates, analogy therefore has been achieved (Gentner, 1983). One example of an analogy is the lung chest model which was constructed using simple household materials such as  plastic bottle, plastic sheet, small plastic bags and flexed straws. Looking closely, overlaps between the object attributes of the model and the human respiratory system are very weak but in terms of relational predicates a strong overlap can be observed. When the plastic sheet goes down the small plastic bags inside the plastic bottle inflate. This  indicates that air rushes inside these plastic bags. In the human respiratory system the diaphragm situated below the lungs also demonstrates a downward movement when it contracts causing the lungs to inflate.  If this model would have object attributes almost similar to the anatomical structure of the human respiratory system, literal similarity would have been attained.

The use of analogical models in the teaching learning process has become a pertinent issue when teachers collaboratively develop research lessons involving three dimensional models as a teaching tool. A lesson study group composed of Grade 5 teachers intended to use a three dimensional model to teach a science concept by analogy. The lesson study group intended to use a hard-boiled egg as their model to represent the interior of the Sun. In light of Gentner’s structure-mapping theory - the hard-boiled egg which serves as an analogical model of the interior of the Sun has been found to be problematic. Object attributes between the target and the base domain do not have several overlaps. If the yolk would correspond to the central core, what will be the counterpart of the Sun’s radiative zone and the convective zone? The egg shell itself may not have a counterpart with the Sun as the Sun’s surface does not have a covering that can correspond to the egg shell. The softness of the yolk and egg white does not have any similarity with the Sun’s interior as the Sun is made up of hot gases. Another consideration is the shape of the egg as the Sun is nearly spherical in shape.   With regards to relational predicates, there is totally no relational overlap observable between the Sun and the hard-boiled egg. The hard-boiled egg’s interior cannot be made to give heat and light as how the core and radiative zones  produce heat and light. When few or no relational overlaps are observed between the target and the base, what can be attained is an anomaly instead (Gentner, 1983).

A snapshot of the research lesson to be implemented is shown below:

Prepared Questions on the Research Lesson 


From the part titled Analysis and Discussion, the teacher tried to narrow down on the fact that the cross–section of a hard-boiled egg has similarities with the Sun which is more prescriptive rather than constructivist in approach. What the implementing teacher failed to see is that the hard-boiled egg cannot be used as an analogical model to make them infer the interior parts of the Sun.

After the first lesson implementation data from the post lesson discussion revealed interesting results from two NISMED staff. NISMED staff 1 gave a firsthand account on some critical areas seen during the lesson implementation while NISMED staff 2 focused more on the shared ideas and comments of the implementing teacher, his co-teachers as well as the general impressions about the implementation.

From NISMED staff 1:

A preliminary activity aimed at unlocking the terms “inner” and “outer” was done.
The Teacher started with eliciting prior knowledge by asking them to draw the inner parts of the sun but he actually just said draw the sun instead of saying draw the inner parts of the Sun.

He conducted another activity by asking the students to draw the cross section of a hardboiled egg and then made them compare the egg and the Sun. The egg model elicited responses that are not related to the parts of the Sun. One student even mentioned the presence of Salmonella in eggs.

When he asked if there is any difference between the sun and the egg most of the students were silent as they do not seem to know how to answer the question. The hard-boiled egg failed to represent fully the interior parts of the Sun as the Sun’s radiative and convective zone have no counterparts that can be found in the hard-boiled egg.

Students were asked to put together the puzzle pieces to show the parts of the Sun. Afterwards, a reading activity about the parts of the Sun was given to the students. They were asked to label the parts of the Sun. The teacher, however, did not give time for the students to label properly the parts of the Sun as the teacher already named one of the parts. 

During the group activity, only a few students were actually engaged in the task assigned to them. 

From NISMED staff 2:
·         After Mr.  ________shared his observations about the activity and his implementation:
o     He found that the activity was time consuming despite giving a time limit for the task;
o     He liked the activity because it gave the students opportunity to relate their previous lessons (from the earlier grades) to the current lesson, and allowed them to observe something concrete (egg model) to anchor the development of their ideas on the current lesson; and
o     He expressed that the objectives he set for the lesson were met to a certain extent since they were not able to finish the lesson.
·         The impressions and observations of the rest of the team (co-teachers and NISMED staff 1) were similar to his observations with regard to the length of time spent in doing all the activities. Several suggestions were cited by different members of the group to address this (see the decisions in the next section). The discussion on time management has implications on the number of tasks for the students and the choice of which tasks to retain in the revised lesson plan.
·         Other aspects of the lesson and lesson plan that were brought to light were:
o   Use of the egg as a model of the Sun – Since the responses of the students showed that they could not easily connect the egg model to the parts of the Sun (only one group made an effort/attempt to make the connection) and was limited to inner and outer parts only;
o   Extent of participation of the members in the group -Only two to three  members were really engaged in the activity due to the big size of the group (10 members ); and
o   Assessment/Quiz – The group was advised by the NISMED staff to review the items based on the revisions that will be made on the lesson plan.

Instead of inferring the parts of the Sun from the egg model, students started to describe the egg as one pupil even mentioned the presence of Salmonella that can also be found in eggs.  The teacher had not realized his role as a facilitator of learning when he immediately named one of the parts of the Sun’s interior. By the teacher’s behavior and the students’ responses, the egg model was not really instrumental in making the students infer the parts of the Sun from the cross section of the egg since the reading activity was the only source that could make the students understand more about the parts of the Sun’s interior.    

NISMED staff gave the following recommendations:

·         Sir ____ will finish the lesson on the following day with the same section (including the quiz), but will no longer be observed by the NISMED staff.

·         Retain the preliminary activity using the pictures of the inner and outer parts of the house for the unlocking of the terms, but only for the low-ability sections. For the high-ability sections, this can be omitted or asked directly to the pupils (What do you think is the meaning of inner/outer?).

·         For the main focus question, stress the interior parts but rephrase it “What do you think is inside the Sun?/What do you think are the inner parts of the Sun?”. The teacher is encouraged to ask this in Filipino especially in the lower-ability sections.

·         To save time, the egg model and the puzzle will be removed. The activities that will be retained are the drawing of the Sun to answer the question, “What do you think is inside the Sun/What do you think are the inner parts of the Sun?” and to elicit prior knowledge. This task will be done individually and drawn in their notebook. Second, the article will be retained, but instead of a group activity, it will be done in pairs (think-pair-share). Moreover, the next task involving the article is for the students to draw and label the parts of the Sun based on what they understood or learned from reading the article.
·         For the presentation of output/drawings, the teacher will tell the students to post their drawings on the board. The teacher will also give them time to view the other pairs’ work and then call volunteers to group similar drawings together. He will then ask for volunteers who will describe their drawings further using their own words.
·         After the selected pairs have presented, this is the time that the teacher shows the image of the Sun (showing the interior parts) with proper labels (labels should be bigger). This time, the teacher will tell the class (pairs) to compare their drawings with the illustration of the Sun that the teacher posted. The students can evaluate for themselves (no need to score) on how close their drawings are to the illustration.
·         Review the assessment items if the tasks and skills required are aligned with the tasks and skills of the revised lesson plan. Include a diagram of the Sun and its parts in the assessment task since the revised lesson will have more visuals.
·         The second implementation will be done by Ms. ______.

For the lesson study practitioner and knowledgeable others who serve as consultants to the lesson study group, it is important to bear in mind the conceptual framework for using models as tools for analogical reasoning. Every time a manipulative model or any three-dimensional model is being used to teach a science concept, the knowledgeable others must be able to analyze the object attributes and relational predicates that overlap between the target and base domain. This is important because “uncritical use of analogies may generate misconceptions and this is especially so when unshared attributes are treated as valid.” (Harrison and Treagust, 1993 p. 1292).       

REFERENCES

Falkenhainer B., Forbus K. D. & Gentner D. (1989). The Structure-mapping engine:
Algorithm and Examples. Artificial Intelligence, 41, 1-63. Retrieved from
http://www.kanga.nu/~claw/PDF/falkenhainer89structuremapping.pdf

Gentner,  D. (1983). Structure mapping: A theoretical framework for analogy. Cognitive
                Science, 7(2), 155-170. doi: 10.1016/S0364-0213(83)80009-3.

Glynn S.H. (1991). Explaining Science Concepts: A Teaching-with-analogies model. In
S.M. Glynn, R.H. Yeany & B.K. Britton (Eds.) The psychology of learning science. Lawrence  ErlbaumAssociates, Inc.: New Jersey.

Harrison, A.G. & Treagust D.F. ( 1993). Teaching with Analogies: A case study in grade
10 optics. Journal of Research in Science Teaching. 30, 1291-1307. Retrieved from  https://www.researchgate.net/profile/David_Treagust2/publication/
227763859_Teaching_with_analogies_A_case_study_in_grade10_optics/links/00b49521bf923c2973000000.pdf 
Krontiris-Litowitz, J. (2003), “Using manipulatives to improve learning in the
Undergraduate neurophysiology curriculum”, Advances in PhysiologyEducation, Vol. 27 No. 3, pp. 109-119. doi: 101152/advan.00042.2002.


McLaurin, D.C., Halverson, K.L. and Boyce, C.J. (2014), “Using manipulative models to
develop tree thinking”, Biology International, Vol. 54, pp. 108-121, available at:
http://biologyinternational.org/wp-content/uploads/2014/03/
11Halverson-Vol-54.pdf (accessed September 12, 2014).

Orgill, M. & Thomas, M. (30 December 2005). Analogies and the 5E model. National
 Science Teachers Association. Available at http://www.nsta.org/publications/
news/story.aspx?id=53146




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