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DWI SRI MULYATI
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Jumat, 11 Januari 2013
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Rabu, 19 Desember 2012
CTL jurnal
Strategies for mathematics: Teaching in context
Abstract (summary)
Active learning in motivating contexts
is the foundation on which constructivist teachers build their teaching strategies and classroom
environments. Within the context of mathematics
education, Crawford and Witte explain how to craft learning experiences that invite
interaction and help students apply knowledge.
Headnote
Active learning in motivating contexts
is the foundation on which contructivist teachers build their teaching strategies and classroom
environments.
The word
that best describes a constructivist mathematics
classroom is energy. Young people bring tremendous energy. Rather than fight to
contain it, teachers in
constructivist classrooms direct this energy by engaging students actively in the learning process.
In these classrooms, students are more likely to participate in hands-on activities than to
listen to lectures. They are more likely to discuss with other students their
solution strategies than to ask the teacher to tell them the right one. They
are more likely to work cooperatively in
small groups as they shape and reformulate their conceptions than to practice mathematics rules silently at
their desks. In
constructivist classrooms, teachers establish interest, confidence, and a need
for mathematics by
capitalizing on students' energy.
Active
engagement requires a classroom that looks different from a traditional mathematics classroom and
contains such supplies as manipulatives, measuring devices for hands-on
activities, and reference material for problem-solving activities and projects.
Usually, desks are not lined up in
rows. Arranging a classroom so that groups of students can work together
signals an active learning
environment, invites student interaction, and supports a learning community. All eyes are
not focused on the teacher at the front of the room. With diligent work toward
developing trust between teacher and student as well as among students, a
teacher can create a culture and a climate of community.
In our years of teaching,
supervising, and developing curriculums, we have observed outstanding teachers
create these classroom environments. Even though many did not know the word,
their classrooms were and are models of constructivism. Each of these teachers
is unique, and each uses diverse methods. But we have observed five common
attributes, which we call contextual
teaching strategies: relating, experiencing, applying, cooperating, and
transferring. These strategies focus on teaching and learning
in context-a fundamental principle of constructivism.
Relating
Relating is
the most powerful contextual
teaching strategy and is at the heart of constructivism. We use the term
relating to mean learning in
the context of one's life experiences.
Ms. Herrera (all teachers' names are pseudonyms) is a 9th grade pre-algebra
teacher. She uses relating when she links a new concept to something completely
familiar, thus connecting what her students already know to the new
information. When Ms. Herrera is successful, her students gain almost instant
insight. Caine and Caine (1994) call this reaction "felt meaning"
because of the "aha" sensation that often accompanies the insight.
Insight can
be momentous. We have all experienced the relief and energy that occur when the
many seemingly disparate pieces of a complicated problem fall into place. At
that moment, we finally understand the problem in its entirety, and we can see the solution.
But felt
meaning can also be subtle when these insights lead to a milder reaction:
"Oh, that makes sense." Consider a lesson on ratio and proportion. A
traditional approach typically begins with a definition, followed by an
example:
A ratio is a
comparison of two numbers by division. Suppose that a bag contains five
marbles. Three of the five marbles are blue. The numbers 3 and 5 form a ratio.
Ms. Herrera
begins by asking two questions that almost every student can answer from life
experiences outside the classroom: "Have you ever made fruit punch from
frozen concentrate? What did the instructions
say?" She then reads from a real container: "Mix 3 cans water with I
can concentrate." Now she can connect this familiar situation to the
definition of ratio.
When they
are presented with the fruit punch example first, most students feet that they
already know about ratio because they are familiar with the experience of
making fruit punch. They are also more likely to remember the definition of
ratio because they can relate it to the fruit punch instructions.
Experiencing
Relating
draws on the life experiences that students bring to the classroom. Teachers
also help students construct new knowledge by orchestratrating hands-on
experiences inside the classroom. We call this strategy experiencing. It is learning by doing-- through
exploration, discovery, and invention. Three general categories of hands-on
experiences create meaning for all students.
Manipulatives.
Students move these simple objects around to model abstract concepts
concretely. For example, baseten blocks model numeric representation in the decimal system. Fraction
bars demonstrate the meaning of simple fractions and adding and multiplying
fractions. Area tiles model the multiplication of polynomials.
Problem-solving
activities. These hands-on activities engage students' creativity while teaching problemsolving skills,
mathematical thinking, communication, and group interactions. In her fruit punch lesson on
ratio and proportion, Ms. Herrera poses a followup question: "How many
cans of concentrate and how many cans of water are needed to make punch for the
whole class?" Several problem-solving approaches and solutions are
possible because the answers depend on her students' assumptions: How much
punch is needed? How can we make sure that we use the same 3: 1 ratio of water
to concentrate? At the end of the lesson, the students as a class decide on a
single best solution and then make the fruit punch to "check their
answer."
Laboratory
activities. During laboratories, students collect data by making their own
measurements, analyze the data, and then reflect on the mathematics concepts. In Mr. Anderson's firstyear algebra class, groups of
students measure their heights and arm spans. The class combines the groups'
data, plots the data, and draws a line of best fit. Then students measure Mr.
Anderson's arm span and use the fitted line to predict his height. This
activity teaches ordered pairs, plotting ordered pairs on a coordinate plane,
drawing a line of best fit, and the power and utility of a correlation. By
using their own data, students are more likely to develop a sense of
understanding, or felt meaning, for these concepts.
Teachers can
orchestrate problemsolving and laboratory activities to show how students'
assumptions and methods affect the final outcomes. Many of us are attracted to mathematics because it is a
"pure" science-there is always a right answer to a problem and all
others are wrong. But when individuals' perceptions are involved, assumptions,
formulations, and interpretations of results can differ.
In Mr. Anderson's class, if two students independently use the same set of
data points to draw a line of best fit "by eye," the two lines will
not be identical and will lead to different predictions of Mr. Anderson's
height. In a constructivist
classroom, these differences are important. Through them, students learn that
multiple perceptions exist and that even in mathematics, the "right" answer can be a matter of
interpretation.
Applying
We define
the strategy applying as learning
by putting the concepts to use. Obviously, students apply mathematics concepts in hands-on, experiential, and
problem-solving activities. Some teachers successfully use openended problems
or projects as opportunities for applying mathematics. In
addition, teachers can use realistic and relevant exercises to stimulate a need
for mathematics.
These math-application exercises are
similar to traditional textbook word problems, with two major differences: They
pose a realistic situation and they demonstrate the utility of mathematics in a student's life,
current or future. Both are important for a math application to be motivational. The following
is a typical word problem from a lesson on the volume of solids:
A
hemispherical plastic dome covers an indoor swimming pool. If the diameter of
the dome measures 150 feet, find the volume enclosed by the dome in cubic yards.
It may be
real, but how would a teacher answer a student who asks, "So what?"
Ms. Hayes
assigns a problem in her
geometry class that also involves calculations with volumes of solids. In this problem, mathematics is crucial in a believable decision-making
situation. The problem inherently answers "So what?"
Montgomery
is a compounding pharmacist at a pharmaceutical manufacturing plant. He is
responsible for selecting the correct capsule sizes for specified dosages of
the company's products. When a compound is prepared, the capsule size
determines the dosage. The company uses eight sizes. The body length l^subb^,
cap length l^sub C^, and diameter d of the capsules are shown in figure 1.
Montgomery
must select a capsule size for a 25-milligram dosage of an antidepressant. Each
capsule must contain 650 +/-10 mm^sup 3^ of the compound. Which size should
Montgomery select?
All students
will see the importance of the math
concepts in solving this
realistic problem. But because not all students aspire to become pharmacists,
Ms. Hayes assigns problems that cover diverse situations. All her students find
realistic scenarios that are applicable to their current or possible future
lives outside the classroom, as consumers, family members, recreationists,
sports competitors, workers, and citizens.
Relating and
experiencing are strategies for developing felt meaning or understanding.
Applying is a strategy for developing a deeper sense of meaning-a reason for learning. Relating and
experiencing foster the attitude that "I can learn this." Applying
fosters the attitude that "I need (or want) to learn this." Together,
these attitudes are highly motivational.
Cooperating
Many
problem-solving exercises, especially when they involve realistic situations,
are complex. Students working individually sometimes cannot make significant
progress in a class period
and become frustrated unless the teacher provides step-by-step guidance. But
students working in groups
can often handle these complex problems with little outside help. When Ms.
Herrera, Mr. Anderson, and Ms. Hayes use student-led groups to complete
exercises or hands-on activities, they are using the strategy of cooperating-- learning in the context of
sharing, responding, and communicating with other learners.
Working with
their peers in small
groups, most students feel less selfconsciousness and can ask questions without
a threat of embarrassment. They also will more readily explain their
understanding of concepts or recommend a problem-solving approach for the
group. By listening to others, students re-evaluate and reformulate their own
sense of understanding. They learn to value the opinions of others because
sometimes a different strategy proves to be a better approach to the problem.
Hands-on activities and laboratories are best done, and sometimes must be
done, in groups. Many
teachers assign student roles for these activities, such as equipment
custodian, timer, measurer, recorder, evaluator, and observer. Roles instill a
sense of identity and responsibility and become important as students realize
that successfully completing an activity depends on every group member doing
his or her job. Success also depends on other group processes-communication,
observation, suggestion, discussion, analysis, and reflection. These processes
are themselves important learning
experiences.
Cooperative learning places new demands on
the teacher. The teacher must form effective groups, assign appropriate tasks,
be keenly observant during group activities, diagnose problems quickly, and
supply information or direction necessary to keep all groups moving forward. As
with the other contextual teaching
strategies, the teacher's role changes. He or she is sometimes lecturer,
sometimes observer, and sometimes facilitator (Davidson, 1990).
Transferring
In a traditional classroom, the teacher's primary role is to convey knowledge
to students. In a
constructivist classroom, knowledge moves in three directions: from teacher to student, from student to
student, and even from student to teacher (Brooks & Brooks, 1993). Contextual teaching adds another
dimension to this person-to-person transfer. Transferring is a teaching strategy that we define
as using knowledge in a new
context or situation. Transferring is especially effective when students use
newly acquired knowledge in
unfamiliar situations.
Excellent teachers have the ability to introduce novel ideas that motivate
students intrinsically by evoking curiosity or emotions. In his second-year algebra class,
Mr. Whan distributes a magazine article whose author cites statistics to argue
that young people should not be allowed to obtain a driver's license until they
are 18. Predictably, Mr. Whan's 16- and 17-yearold students react emotionally
to this argument.
Mr. Whan
uses this source of energy to engage his students in a lively debate. Then he assigns the class, in groups, to evaluate the
article. Their written critiques must include an analysis of the mathematics. Were statistics
misused? Were facts or assumptions misrepresented or omitted? Was the argument
logical? If the critiques are persuasive, Mr. Whan will encourage the students
to submit them to the editor of the magazine as rebuttals.
Students
also have a natural curiosity about unfamiliar situations. Mr. Whan capitalizes
on this curiosity with the following exercise:
A sheet of
notebook paper is approximately 2 mils thick. (A mil is one-thousandth of an
inch.) If you fold a sheet of notebook paper in half, the total thickness is 4 mils. If you fold
it in half again, the
thickness becomes 8 mils. Suppose that you could fold the paper 50 times. Which
of the following best describes the total thickness?
a. less than
10 feet
b. more than
10 feet, but less than a 10-story building
c. more than
a 10-story building, but less than Mt. Everest
d. more than
the distance to the Moon
Although
folding a sheet of paper is not novel, students cannot be familiar with 50
folds because it is impossible to fold the paper that many times. Mr. Whan asks
his students to discuss the possible choices of thickness and to vote as a
group for the one they predict to be true. A spokesperson for each group
explains the rationale for its prediction. After the votes are tallied,
students have bought in to
the problem and are eager to know the right answer. At this point, Mr. Whan has
each student group calculate the thickness. The mathematics involves sequences, patterns, conversion
factors, powers, and scientific notation. As a wrap-up, Mr. Whan leads a class
discussion about why most predictions were wrong.
Mr. Whan
uses exercises like this to evoke curiosity and emotion as motivators in transferring mathematics ideas from one
context to another. And conversely, felt meaning created by relating,
experiencing, applying, cooperating, and transferring engages emotions. One of
Caine and Caine's 12 principles of brain-based learning says that "emotions and cognition
cannot be separated and the conjunction of the two is at the heart of learning (1994, p. 104). Although
they did not use the term constructivism, their ideas about felt meaning,
emotions, and cognition clearly paved the way:
The brain
needs to create its own meanings. Meaningful learning is built on creativity and is the source of
much of the joy that students could experience in education. (P. 105)
Creativity
and joy are two descriptors that we often associate with the classrooms of our
best teachers. Others are laughter, motivation, engagement, attention,
imagination, communication, and group processes. How much could mathematics learning improve if
these described the classrooms of our average teachers?
jurnal active learning
Active learning of mathematics
Abstract (summary)
Smith
discusses the importance of active
learning techniques in
the mathematics classroom.
A teacher working with this view would have to provide students with
opportunities to create their own theories and to engage their mental
model-making processes.
Full Text
SINCE THE
COCKCROFT REPORT IN 1982,
THERE HAS BEEN AN increasing emphasis on the use of active learning in school mathematics, with a typical and influential view
being propounded in Better Mathematics: "Mathematics can be effectively
learned only by involving pupils in
experimenting, questioning, reflecting, discovering, inventing and discussing. Mathematics should be a kind of learning which requires a minimum
of factual knowledge and a great deal of experience in dealing with situations using particular kinds of
thinking skills" (Ahmed 1987, 24).
During the
same period of time, there has been an increased explicit and implicit use of a
constructivist epistemology, for example in an implicit way: "The teachers job is to organize and
provide the sorts of experience which enable pupils to construct and develop
their own understanding of mathematics,
rather than simply communicate the ways in which they themselves understand the subject" (NCC
1989, para. 2.2).
And in an explicit way: "Many
writers embed their view of active
learning in a framework concerned with the nature of the intellectual
activity taking place, most often located within a constructivist model of
mathematical learning"
(Kyriacou 1992, 312).
We can, with
some consistency, summarize this particular constructivist framework as the
hypothesis that human knowledge is personally constructed and consists of
conjecture, unfalsified theories, modified theories and expectations.
A teacher
working with this view of how we come to know would have to provide pupils with
appropriate chances to create their own theories, to engage their mental
model-making processes and to allow them the opportunity to develop
expectations in order to
subject their theories to the test of reality. This [approach] strongly
suggests that pupils must be actively engaged in constructing their understanding, and that the
activities themselves must be judged mainly by their contribution in assisting pupils to construct
their own understanding of concepts selected by the teacher.
Within this
particular constructivist framework, learning
tasks should be chosen with the specific intention of actively involving
learners in seeking to
understand their external world by creating and testing their own models of
what is going on "out there" in reality. The teacher has a clear initial role in selecting activities that are
expected to focus the attention of the learner on constructing the intended learning outcomes of the session.
The mathematical activities should therefore be selected or designed to
encourage the learner to link between external world and internal thought. This
involves a consideration of presentation, pupil activity, reflection and
socialization. Activity by itself is not enough.
Presentation
WE MUST AIM
TO PRESENT ANY MATHEMATICAL ACTIVITY in
a way that invites pupils to fully engage their higher mental capacities. This
can be by the use of a game, a puzzle, a surprise or some other intriguing
challenge. In creating a
challenge for learners, we must be aware of the need to choose an appropriate
level of challenge; one that learners can perceive as offering them a
realistic, but not certain, chance of meeting. The challenge can come from the
teacher or from the pupil themselves. It can be in the form of a puzzle, a target to reach, a goal
or a conflict to resolve.
An example
of a presentation that involves all four of these aspects is to motivate
pupils' work on geometrical construction. One way in which I have done this is to show pupils a
hexaflexagon, on the front of which is drawn a pattern and on the reverse, a
different pattern. Pupils are asked to memorize the patterns, and whilst they
attempt to do this, I flex the hexaflexagon whilst maintaining the same pattern
on the front, then ask, "Who can remember the pattern on the back?"
and surprise the class by showing that the pattern has "disappeared."
The goal is then set for the class members to make their own hexaflexagon,
resolving the puzzling disappearance of the lost pattern. I have found this to
be a simple yet highly motivating presentation, which sometimes generates a round
of applause-I wish I could say that more often!
In creating the initial challenge, surprise and cognitive conflict can be
useful to generate interest. For example, by asking pupils to work in pairs and giving one of each
pair a basic calculator and the other a scientific calculator, we can create
cognitive conflict and surprise if we ask pupils to carry out calculations
(like 2 + 3 x 5) that give different answers on the two calculators. The role
of the presentation is to indicate to the learner the need for new or revised
theories; the role of the challenge, surprise or cognitive conflict is to
engage the learners' full attention.
Pupil
Activity
TO SOME
EXTENT THE ROLE OF PUPIL ACTIVITY IS clear; it is for learners to undertake in order to meet the challenge
set by themselves, the teacher or the text. They should be trying to make sense
of the challenge, the activity and their findings. It can therefore be to move
toward the goal, or to attempt to resolve a cognitive conflict, or even to
explore the extent of the cognitive conflict. For example, to continue with the
calculator challenge, we might ask pupils to find out as many sums as they can
that lead to different answers on the different calculators.
The key
aspect of any learning
activity is that it must be constructed or chosen to demand mental involvement;
perhaps this is best achieved by requiring pupils to deal with new, unfamiliar
and nonroutine activity. Familiar mathematics
can often be packaged in an
unfamiliar way; for example, I recently worked with a Y10 top set class
studying graphical inequalities. To do this, I began by placing the pupils in a rectangular array and
systematically giving each person a set of coordinates. By asking pupils to
stand up if they satisfied inequalities like 2x + 3y > 5, I involved all the
pupils in thinking about
the familiar coordinates in
an unfamiliar way. The class teacher reported that "the activity
maintained interest, was fun and entertaining and got across what I usually
find pupils have difficulty with very clearly. The physical nature of the task
helps keep interest and minds awake!"
The task
should not be a passive routine, such as factorizing fifty similar-looking
equations. Practice may be important to develop skill, but from this
perspective the less routine there is in
it, the more learning is
likely to be achieved. In
writing of the importance of a firm conceptual understanding, HMI state that
". . . progress in
pupils' mathematical understanding is more important than progress in the performance of skills. In fact, when the early stages of
learning are firmly
established subsequent progress can take place more quickly and
confidently" (HMI 1985, 36).
Reflection
ON
COMPLETION OF AN ACTIVITY, A REVIEW OF THE learning achieved during the activity can be most helpful in assisting the learners to
integrate their new or revised theories and expectations with their other
mental systems.
"Activity
per se is not a guarantee of mathematical learning" (Goodchild 1992, 24). Goodchild goes on to
consider the importance of reflection and "interpretation," which he
sees as a mechanism for making sense of the learning activity and for locating it in a wider framework of meaning
and purpose. Alternatively, it may be seen as a process in which new personal theories are created or
existing personal theories modified and in which new expectations may be created. The teacher's role in this process is to ensure that
there is time for such reflection, and to provide a mechanism to ensure that
reflection occurs. The classroom organization of reflection may involve pupils in writing, or it may involve
structured discussion with other pupils or with the teacher.
"When
asked for the connections between practical work and the symbolic statement of
rule, the children's best reply was that one was a quicker route to the answer
than the other. Nobody mentioned that the practical experience provided the
data on which the formula was built. The teachers did not stress why this
procedure was being followed, nor emphasize the generalizability of the rule
and thus the advantage of accepting it" (Hart 1989, 139).
Within the
theoretical framework outlined above, it may be seen as appropriate to ask
pupils to be explicit about some new expectations. This obliges pupils to
create both theories and expectations. To continue the calculator example: once
pupils have amassed a number of calculations that give different answers on two
calculators, they can be asked to predict the two answers for other
calculations, to predict when the calculators will give the same answers and to
predict when they will give different answers.
Socialization
"KNOWLEDGE,
FROM THE CONSTRUCTIVIST POINT OF view, is always contextual and never separated
from the subject. . . to know also implies understanding in such a way that the knowledge
can be shared with others and a community thus formed. A fundamental role is
played by the negotiation of meaning in
this interaction, which is of a social nature" (Moreno-Armella and Waldegg
1993, 657).
I do not
believe that many pupils achieve this socialization of knowledge whilst working
from individualized schemes. Even the pronunciation of key mathematical words
(e.g., "sin" instead of sine) is missing, let alone the opportunity
to discuss mathematical problem solving in depth. Socialization cannot be delegated to textbooks.
Having
developed an understanding of a mathematical concept, there is a need for
pupils to be able to communicate effectively about it. For this [requirement],
there is often a need to know, understand and use the appropriate language and
terminology and to adopt the standard conventions. In other words, there is a need to socialize the
personal and private understanding. The teacher has a role here in ensuring that the need for
communication is apparent, that activities incorporate discussion work to
facilitate such communication and that pupils are helped to become aware of
conventional language and notations. "The use of discussion as a technique
for teaching centres on the
fact that it is above all else a means of escaping from our own individual
perceptions of the world, with all their circumstances and boundaries into
which we would otherwise be locked. It adds to the richness of understanding
and enables us to make contact with the minds of others in the most direct way possible" (Van
Ments 1990, 17). During the socialization process, the individual is being
expected to negotiate a shared meaning with the teacher, peers, external
examiners and textbooks largely by coming to grips with conventions and
conventional language. If all pupils in
a group are encouraged to communicate about their mathematical activity, this
[approach] can provide a richer learning
environment for each individual, as well as begin the process of negotiating
shared meanings and socializing the new knowledge.
Conclusion
IN THIS ARTICLE, I HAVE CONSIDERED A CONSTRUCTIVIST framework for the
analysis of mathematical learning
activities. This analysis suggests that mathematical activities are not enough
to achieve learning by themselves;
they need to carried out with a consideration of aspects of presentation, the
nature of the pupils' mental activity, the need to ensure pupil reflection and
the achievement of socialization of the learning.
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