Steven is claiming that given 5 questions, with 5 answer alternatives each,
that all students will get at least 1 item correct by random guessing in
ALL situations. This 1 item correct is what is needed when guessing at 5
items to "break even" with a 1/4 point deduction for wrong answers.
The claim I'm making is that given the same situation, students will get 1
item correct ON AVERAGE. This means that, although most students will get
the statistical 1 item correct, others will get more than 1 item correct
and some will get less than one item correct. I do not agree that EVERYONE
will get at least 1 item correct, only some will get this score. My
understanding of probability is that it works ON AVERAGE, not in isolated
cases. So, most students will break even, or even benefit, from guessing,
but some portion of students will actually lower their score by guessing
because they fail to get the 1 item correct.
Lucky for us, this is something we can test (no voting required)... Have
your students take out a sheet of paper and randomly guess the answers to 5
non-existent questions. Each question has a possible answer of a, b, c, d,
or e. Since we want them to truly guess randomly, we will not actually give
them questions... we just want them to randomly give us the responses.
Here is the key to use to grade the responses: C E D E D
Now, grade the quizes... if ANY student fails to get at least 1 correct,
the claim that it will NEVER hurt a person's score is false. At this point
we know that Steven's claim does not have support from the data. If you
continue scoring for everyone, you can figure out if my claim of getting 1
correct, ON AVERAGE has support or not.
Until we have actual data collected on this, I don't see much point in
guessing as to the benefits or costs of guessing...
- Marc
G. Marc Turner, MEd
Lecturer & Head of Computer Operations
Department of Psychology
Southwest Texas State University
San Marcos, TX 78666
phone: (512)245-2526
email: [EMAIL PROTECTED]
