It seems that when this study first came out sometime back, I marveled at
the fact that this was an extremely ridiculous use of regression. I even
mentioned it to one of my classes (and took some comfort in the fact that
the offending author was not a psychologist, whew!).
What these results indicate is basically a flat regression line which means
there is no relationship. No statement of statistical significance is made
and I have to assume that there is none. Instead of concluding that students
will have to spend huge amounts of time studying to improve their grades,
the proper conclusion is that there is no evidence of a direct relationship
between grades and time spent studying. (This is certainly a worthwhile fact
to remember for my students who come to me complaining that they spent x
number of hours studying for my test and they still did poorly on it).
I believe that any relationship that may exist between the two is hidden by
the fact that good students (those with the highest grades) do not have to
study as much as poorer students to do well and failing students spend a
great deal of time studying in ways that are not helpful.
In any case, the most ridiculous conclusion that can be drawn from a flat
regression line is that huge increases in study time will be required to
raise grades. That is like saying you can deduce a causative relationship
from an almost zero correlation. Similarly, if there is an increase of .025
of a grade for each hour spent in leisure activities outside of school
(basically a zero correlation), a person would have to relax for 80 hours to
get an increase of two letter grades. That is nothing but a blind and
uninformed application of linear regression.
Another horrible example is when they say that for each additional hour of
work, a person loses only .14 of an hour of study time. If there is no limit
to this relationship, we just found a way to turn back the clock. I should
be able to take on a full 40 hour a week job and only lose about 11 hours of
studying. Working 80 hours would only cost me 22 hours of studying.
Eventually, I will actually be adding hours to the week by taking on more
responsibilities at work. Where did these people learn to interpret a
regression and how do people get these things published? Their license to
practice statistics should be revoked.
Rick Froman
John Brown University
[EMAIL PROTECTED]
-----Original Message-----
From: Jeff Ricker [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, July 31, 2001 9:17 AM
To: TIPS
Subject: The secret to academic success: hours--and hours--of study
The secret to academic success: hours--and hours--of study
COLUMBUS, Ohio - Improving a lackluster grade point average takes more
than a few extra hours of study each week. In fact, a study of 79
college students found that a one-letter-grade increase in quarter GPA
was associated with a 40-hour increase in weekly study time.
"A lifestyle change has to happen before an impact is made on a
student's grades," said Carl Zulauf, a study co-author and a professor
of agricultural, environmental and developmental economics at Ohio State
University. "A few extra hours of study each week isn't going to do it."
Overall, the study found that every additional hour spent studying per
week meant only a 0.025 increase in GPA. "This finding raised the
question of whether educators should be resigned to this small
relationship between effort and reward," Zulauf said. "Or perhaps
changes need to be made in how educators evaluate a student's efforts."
The study appears in a recent issue of the Journal of College Student
Development. Zulauf conducted the study with Amy Gortner Lahmers, a
former student of Zulauf's who is now with the Ohio Soybean Council.
The researchers asked 79 college students to keep a time diary for one
week in the middle of a 10-week quarter. Each day was broken into
half-hour intervals, and students were required to indicate how much
time they spent on activities such as attending class, studying,
working, socializing, watching television and sleeping. The students -
freshmen through seniors - were enrolled in one of three agricultural
economics classes at Ohio State. Researchers also had access to both the
participants' cumulative GPAs, as well as the students' GPAs for the
quarter during which the study took place.
Each student also completed the Time Management Behavior (TMB) scale, a
34-question scale that measured time management ability. The questions
were rated on a scale of 1 to 5. Each one-point increase in total TMB
score was associated with a 0.3 increase in GPA, Zulauf said.
"The ability to use time is positively related to academic performance,"
Zulauf said. "But it takes a lot of commitment by a student to
significantly increase the number of hours he studies."
The students in the study spent an average of 17 hours in class per
week, and about 20 hours of study time outside of class during the week.
"This kind of schedule is equivalent to a full-time job," Zulauf said.
And the current recommendation is two hours of study for every hour of
time spent in class.
"So conventional wisdom says that the students in our study should be
spending at least 34 hours studying outside of class," Zulauf said.
"Either this is an unreasonable recommendation, or students are taking
too many courses."
"If a student devoted more time to studying during the quarter, chances
were good that his cumulative GPA increased," Zulauf said.
The researchers looked at the effect that holding down a job had on time
spent studying. On average, each additional hour spent working reduced
the amount of time spent studying by 14 minutes per week. But having a
job didn't seem to have a serious impact on a student's GPA at the end
of the quarter, unless the student was also carrying a heavy course
load, Zulauf said. "If a student can properly manage his time, a
part-time job has little impact on GPA," he said.
The researchers also found that the higher a student scored on the ACT -
a college admissions test - the more time he spent in class, and the
less time he spent studying. But fewer hours of study didn't mean a
lower GPA for these students. "Each one-point increase in ACT score
meant a 0.095 increase in the GPA for the quarter," Zulauf said.
Contact: Carl Zulauf, (614) 292-6285; [EMAIL PROTECTED]
Written by Holly Wagner, (614) 292-8310; [EMAIL PROTECTED]
--
Jeffry P. Ricker, Ph.D. Office Phone: (480) 423-6213
9000 E. Chaparral Rd. FAX Number: (480) 423-6298
Psychology Department [EMAIL PROTECTED]
Scottsdale Community College
Scottsdale, AZ 85256-2626
Listowner: Psychologists Educating Students to Think Skeptically (PESTS)
http://www.sc.maricopa.edu/sbscience/pests/index.html
