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The cases serve as springboards to student-designed
investigations.
Students structure their own learning, using the
"story" of the case as a focus. Although the case defines
the general area of biology under investigation, students generate
the questions that will define their own topic of study. These cases
are useful for lifelong learning because they are open-ended and
draw from a broad range of situations in which biology and scientific
reasoning can be applied. Open-ended cases necessarily shift the
focus of student learning beyond the facts of science to include
using scientific knowledge to frame questions and to answer them.
Investigative case-based approaches to biology
encourage problem posing, problem solving, and persuasion.
Instructors as well as the students are collaborators
in this process. As students pose problems, try to solve them, and
present conclusions that represent their own findings to others,
both the instructor and other students may serve as resources for
methods and for aid in defining potential strengths and weaknesses
in the design of the problem statement and the investigation. The
resolution(or clarification) of the problem and its presentation
to other students as well as to the instructor extend opportunities
for student practice in utilizing and evaluating scientific approaches
to problem solving.
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Lessons from problem based learning
in medical education:
Our approach to case study grew out of experience
with medical case-based PBL. Some elements of that approach are
extremely useful and are retained in the investigative case study
approach..
1. Cases are based on realistic and meaningful
problems, they are multidisciplinary
In the case study approach students learn biology
in the context of realistic situations. They have practice using
biological information to investigate and come to resolution on
complex problems. Since learning occurs around a particular realistic
problem, there is greater likelihood that the learned material will
be better retained and more easily applied to similar situations
(Brown et al., 1989, Schmidt, 1983). In their lives they may never
face the exact problems they study, however, they will have experienced
using scientific knowledge and scientific thinking to work out reasonable
solutions.
2. The case defines a problem space
In case-based PBL, the problem is used in a different
fashion than problems are traditionally used for science learning.
In PBL the case defines a problem space that learners will investigate.
In case-based PBL, the case problem comes first in the instructional
sequence. This is a reversal of the usual use of problems in science
teaching. By putting the case early in the instructional sequence,
the learners use the case to brainstorm a set of questions they
will try to answer. They thus become more directed in their reading
and more motivated in subsequent lectures, labs, and discussions.
In fact, they are learning in just the way most of us learn-- because
they have a problem or question of their own to work on.
An example of a medical case:
Ben Brown seemed lost as he approached
the emergency room at General Hospital with a young boy.
"You looking for the hospital's homeless shelter?" the security
guard asked. "No. My dad's sick" said the boy as Ben coughed
violently, spitting out bloody mucus. The guard jumped aside
"Hey, watch it! Don't get that on me! Yeah, alright. Go
on in." Case Author: Margaret Waterman, 1997
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Faculty members choose cases or write their own,
and so draw the boundaries on the problem space. The case defines
a problem space in much the same way that the lines on a soccer
field defines a playing space. As in soccer, the case sets some
limits on the area of subject matter to be explored. And as in soccer,
once the game has begun, the players move over the playing field
moving in general directions, and with goals, but not in a prescribed
linear manner. Unlike soccer, it's ok to go out of bounds for a
while with a case, as long as the general direction and goals are
attained.
3. Students make decisions about their learning,
and
4. Some phases of case study are best done
collaboratively
Commonly in the medical case-based PBL approach,
students work in groups of 8-10 with a "tutor," meeting to discuss
a case based on a real patient or situation (Fig. 2). Students read
part of the case out loud, then discuss the elements presented thus
far in the case. They generate hypotheses, list their outstanding
questions, and develop a learning agenda -- issues they agree to
pursue before their next meeting. This phase of case study is one
in which students are actively engaged and working together to brainstorm
issues, share what they know, and develop their plans for learning.
Some possible learning issues from the Ben Brown
case: Access to health care, causes of coughs, parts of the body
involved in breathing and coughing, the blood supply of the lungs,
homelessness, universal precautions.
5. The faculty member becomes more of a
guide to methodology than an information source.
As you consider case-based learning in the classroom,
think about what a case discussion might look like with a small
group. The "instructor" has several roles (though to the student
eye it may seem he does little): facilitates discussion, helps students
explore their thinking and reasoning without leading them, and helps
with group dynamics. During case discussions, students are actively
engaged in interpreting the case, proposing problems and possible
solutions, brainstorming, and using resources. At Harvard Medical
School the faculty and students agree that the chalkboard belongs
to the student during case discussions. Students take on roles we
commonly think of as teacher roles: deciding what to focus on, developing
questions, leading the discussion, using the board to keep notes,
make drawings, or list learning issues. Resources to support student
learning are frequently in the room - books, images, computer access
to the Internet, computer simulations, models, etc.
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