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A critical view to
assessment of Web-based instruction
Chong Ho Yu, Ph.D.s
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Metaphor of medicial treatment
- Once upon a time a man got a cold and visited a doctor. The doctor
gave him some cold medicine, of course. A few days later, the patient
was recovered. The physician claimed that his treatment was effective.
- In a scientific viewpoint, this claim is not valid. First,
the doctor did not know whether the patient took the medicine or not.
Second, even if the patient took the drug,
he could not tell what effects the drug made to the patient's body. As
a matter of fact, a cold could be healed without any intervention. To
validate his claim, the doctor should sample and analyze the patient*s
blood right after he took the medicine.
Input-process-output
In my experience, today quite a few assessments of Web-based instruction have
the same problem. The instructors deliver contents over the Web and then students
performance are evaluated. A typical approach is to conduct a dependent t-test of
pretest-posttest-difference. But even if performance gain is found, can we claim
that the improvement is caused by the Web? This input-output evaluation should be
replaced by an input-process-output evaluation. To check the effect of a drug,
a doctor should track down the chemical reaction of the drug inside the patient's
blood. By the same token, a cyber-teacher should analyze the usage of webpages by
learners and correlated the user activities with the test scores.
Frequent users of the Web may have better test performance. But what if
infrequent Interent users also have high performance? If so, the change in
performance may not be caused by the use of the Web.
Metaphor of magicial healing
- Once upon a time a magician handed a bottle of "holy water" to a
patient and told him, "This bottle of water is not ordinate water. It
possesses the divine power from God. If you have faith on it, it will
heal your illness." The patient drank the water and his disease
disappeared. The magician claimed that his "holy water" has healing
power.
- Again, in a scientific viewpoint this claim has no merit.
The recovery might be caused by the patient*s belief and thus he got
what he expected to see. In psychology it is called "placebo effect"
and in sociology it is called "self-fulfilling prophecy."
Self-fulfilling prophecy
- Some assessments of Web-based instruction has the same potential
flaw as the
above. In their classic book "Experimental Design," Cook and Campbell
explicitly
warned researchers about this kind of possible bias of experiments.
A well-thought researcher should hide the true intention of the
experiment in order to avoid the subjects to behave in "expected"
manner. However, not only some instructors do not "blind" the subjects,
they "evangelize" that the Web is a wonderful and revolutionary
learning tool. Hence, the performance increase of students may be
contributed by motivational variables rather than technological
variables. Nonetheless, this weakness is understandable. It is common
that instructors are
excited by new technologies.
- Further, some researchers are aware of this matter, but
they do not want to lie to students such as saying "We deliver
Web-based instruction because there are not enough parking lots on
campus. So you should stay home to attend online classes." This
involves an ethical issue.
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