Archive for the ‘Education’ Category

The effect of graded homework assignments on other grades

Friday, May 4th, 2012

Here’s a comparison I did of the results of using graded homework assignments in a freshman-level chemistry class.  The classes compared all had homework assignments given each week, but only some of them had assignments that were taken up, graded, and counted directly towards the final course grade.

Change in average test scores

As you can see, there was a nearly a letter grade improvement in scores on the first test, compared to classes that didn’t have the graded assignments.  There was an improvement on the second test as well, though it’s much more modest than the improvement on the first test.  So the graded assignments appear to help students start off the course on a better footing than they would have otherwise.

However, the scores for the third and fourth tests are nearly half a letter grade lower than for the classes without the graded assignments.  What’s the cause of this drop in performance?  A few possibilities:

  • Attrition may explain some of the falloff.  Students who started off more poorly in the classes without the graded assignments are more likely to withdraw from the course earlier – leaving a greater percentage of higher-performing students behind for the last two test.  (The latest a student is allowed to withdraw from a course is shortly after the third test.)
  • Student participation in the graded assignments dropped somewhat as the semester progressed.  More students skipped turning in homework before the third and fourth tests compared to the first and second.
  • Students are more likely later in the semester to copy their assignments from other students of from tutors in the school’s tutoring center – depriving them of any benefit they might have gotten from doing the assignment.

For the final exam, the students in the graded assignments classes showed a small improvement over the others.

Since these classes are small sections as opposed to large auditorium classes, here’s a look at the median change in test scores for the same set of students.

Change in median test scores

The median scores follow roughly the same trends as the averages do – with better performance on the first two tests and poorer performance on the later tests.  Interestingly, the median final exam scores for the students with graded assignments was slightly lower than the median final exam score for students without the graded assignments.

Student sorting

Wednesday, March 9th, 2011

Each semester, I have at least eight hours a week of “office hours”; time when students can come by for assistance with chemistry.  Of the students wh0 drop in for office hours, it’s surprisingly easy to tell students who are likely to pass their courses from students who are likely to fail them.

The students who are likely to pass courses come by with questions related to things we’ve been doing in class.  If they did poorly on an assignment, they bring the assignment in with them and ask specific questions about things they weren’t clear on.  They bring in attempts to work the practice problems provided in their study guides.  In short, they come in to see me to talk about chemistry, since I’ve got experience in helping people learn chemistry.

The students who are likely to fail courses show up at my office door, too.  But they’re at my office for a different reason.  They want to discuss, in abstract terms, why they did not do well on their tests.  Grades come up a lot; these students want to know to the exact point what they need to make on their next test.  But chemistry itself never seems to come up, unless I specifically mention it.

The key difference is that students who will likely succeed come by to discuss things related to the topic of the course.  Students who will likely fail come by to discuss everything except the topic of the course.  Food for thought.


Monday, August 24th, 2009

Looks like flu season has started…

The college has received word of the first confirmed case of the H1N1 virus in one of our students.  The student sought treatment and is now recuperating at home. The faculty members of that student have been informed today and students who were attending those classes will be notified by faculty.

One of the drawbacks of teaching is exposure to every illness that comes around – from common colds, to stomach viruses, to the hottest new flu pandemics.  Sigh.

The expectations gap

Wednesday, February 18th, 2009

Here’s an interesting little NYT article on the gulf between the grades students expect to receive in their college classes versus the grades they actually earn:

A recent study by researchers at the University of California, Irvine, found that a third of students surveyed said that they expected B’s just for attending lectures, and 40 percent said they deserved a B for completing the required reading.

Some college educators refer to this as the “I paid my fee, gimme my B” phenomenon.  The only thing about this study’s results that surprises me is that only a third of the surveyed students expected to get an above-average grade just for showing up.

This leads into a more revealing quote from an interviewed student:

“I think putting in a lot of effort should merit a high grade,” Mr. Greenwood [the interviewed student] said. “What else is there really than the effort that you put in?”

How about demonstrating mastery of the course competencies?  A course grade that’s higher than average should denote that a student has a higher-than-average proficiency with the material covered in the course.  That’s it.

The student continues:

“If you put in all the effort you have and get a C, what is the point?” […] “If someone goes to every class and reads every chapter in the book and does everything the teacher asks of them and more, then they should be getting an A like their effort deserves. If your maximum effort can only be average in a teacher’s mind, then something is wrong.”

Except that the grade reflects mastery of material rather than how much time a student spent sitting at his desk with his textbook and his iPhone.

It’s not quoted in the article, but from my own experiences there’s another underlying issue with student expectations.  Students think that they’re working a lot harder at a course than they really are.  I’ve had students who sincerely believe they’re putting in lots of effort towards a course when I talk to them about what went horribly wrong on their tests.  Here’s how the discussions typically run.

Student:  “I don’t understand why I did so badly on the test.  I studied really hard.”

Me: “Okay.  Well let’s see if we can work out how to get you to do better on the next test.  Let’s take a look at some of the study guide problems you worked out while you were getting ready for the test.  Maybe we can find out what was giving you trouble”   (I teach chemistry, which is very much a problem-solving course.  I give my students study guides complete with practice problems for every unit of material we cover, as well as additional practice sets with solutions on my course web site.)

Student: “Umm…”

Me:  “I think I see the problem.  How did you prepare for this test?”

The student usually says something at this point about “rereading the notes” or “looking at the book”.  While these things might be a small part of preparing for a problem-solving text, most of the actual preparation should be, well, practicing how to solve problems.

Even though glancing at the course notes and skimming over the textbook really isn’t putting real effort towards a class, most of these students I talk to about their study habits seem to think it is.  And that’s what’s really wrong with the student quote above.

With help like this …

Wednesday, February 18th, 2009

There’s an odd headline in The State today:
Bill would help SC schools amid budget cuts
Sounds good, right?  Then you read the article.

South Carolina lawmakers gave key approval Wednesday to a bill allowing school districts to increase class sizes and furlough teachers to absorb budget cuts

That’s “help”?  If cramming more and more students into a classroom and cutting teacher pay (which really isn’t that great to begin with) is meant to help our schools, I shudder to think what a bill hurting our schools would look like.

Stop: Rant time!

Wednesday, February 11th, 2009

It’s the day of the first chemistry test.  Since this is a low-level introductory class, we’ve spent much of the last few weeks learning how to do math for lab work rather than actual chemistry – because when students say they have problems with chemistry, they’re really saying that they have problems with math.

We’ve had extensive demonstrations of how to properly use scientific calculators for routine laboratory calculations.



In short, the students very well know that they’re going to be using their calculators for much of this test.

So … why do students still come to the test without their calculator?  It’s not like there’s a very long checklist of things to bring to the test:

  1. The student’s brain
  2. A pencil or two
  3. A calculator

The next thing you know, some students will be leaving their brains at home on the kitchen table.

Here endeth today’s rant.

No room at the inn

Wednesday, January 14th, 2009

This blog has been quiet recently.  That’s due to the fact that a new semester has started. New semesters mean getting swamped – not only by preparation for the semester’s classes and labs, but also by the onslaught of new students who have only just decided that they need to come to school.

Lots of them.

The president of the State Board for Technical and Comprehensive Education said “enrollment is booming” at the state’s 16 technical colleges – up to 20 percent – as laid off workers seek training for a new job.

That’s something the legislature should consider when deciding how much to slice off of the technical college budget during this legislative session.  Tech schools are retraining the state’s workforce – and they need money to do it.  Withiout adequate funding, students will come … but there will be no room at the inn.

You can’t fight dumb with more dumb

Wednesday, December 10th, 2008

I’m something of a Linux advocate.  I use Linux in my everyday work as an educator, and the only machine in my house that runs a Microsoft OS is the Xbox 360.  So I found this mess linked by both Slashdot and Linux Today somewhat interesting.

If the linked blog post is accurate, a Texas middle school teacher confiscated a boy’s Linux discs because she believed that distributing the discs was illegal.  That’s definitely ignorance on the teacher’s part.  A typical Linux distribution can be freely distributed, and distribution maintainers typically encourage this sort of thing.  That a Texas middle school teacher is not aware of this isn’t really surprising.  And the teacher’s response to Linux distributions is quite silly:

No software is free and spreading that misconception is harmful. […] I along with many others tried Linux during college and I assure you, the claims you make are grossly over-stated and hinge on falsehoods.

After all, all that’s missing from here is “…I didn’t inhale.”***  Clearly, this teacher is in need of some education on what free software is.  She’s clueless.  But the response by the blogger who’s causing all the fuss is just as dumb.

Then again, being a good NEA member, you would spout the Union line. Microsoft has pumped tens of millions of dollars into your union. Of course you are going to “recommend” Microsoft Windows”. To do otherwise would probably get you reprimanded at the least and fired at the worst.

Keep in mind that this is happening in Texas, where teachers are prohibited by law from collective bargaining (or striking).  Texas just isn’t a union shop, and it’s entirely possible that this middle school teacher doesn’t even belong to a union.  And if she did, it’s unlikely to be one that could get her “reprimanded or fired” for using Linux.

Sheesh.  You can’t fight dumb with more dumb.

*** The “I tried Linux in college” quote is the reason I still think the whole thing is satire, and should be posted on The Onion.

Keep ’em out of trouble

Saturday, December 6th, 2008

While I was glancing at the latest America’s Health Rankings, I noticed that South Carolina had both the worst violent crime rate in the nation and the second-worst rate of high school graduation.

So how related to one another are those two factors?  Here’s a simple X-Y chart, showing violent crime rates compared to high school graduation for all fifty states.

Violent cimes vs. percentage of 9th graders who graduate high school

Violent crimes vs. percentage of 9th graders who graduate high school

While correlation is not the same thing as causation, this chart certainly suggests that more educated states have less problems with crime.  That’s something to think about when it comes time to decide how much money to allocate to schools.

Not really a mystery

Wednesday, December 3rd, 2008

The Greenville News tells us about a report that says South Carolina’s colleges rate an “F” in affordability:

South Carolina got an “F” in college affordability on a national higher education report card released today, underscoring a concern cited by members of South Carolina’s Higher Education Study Committee.

Poor and working-class families must devote 34 percent of their income, even after aid, to pay for costs at public four-year colleges, according to the 2008 higher education report card, Measuring Up 2008, from the National Center for Public Policy and Higher Education.

We have high tuition here in South Carolina, and it’s gone up quite a bit over the eight or so years I’ve been teaching.  Why tuition has been skyrocketing – and it’s gone up a lot not only among the four year schools mentioned in the article, but at South Carolina’s two-year colleges as well – isn’t really a mystery.  Look at state funding.  While college enrollment has been increasing, state funding for colleges has been decreasing.  Even before the massive budget cuts we’ve been having in higher education this year, the budget for our two year schools was less than it was eight years ago.  (I assume that four year schools have similar issues.)  So what do schools have to do?  Raise tuition to make up some of the shortfall.

It should not surprise us that when we shortchange higher education, we end up with higher education that is more inacessible to those of us most in need of a quality education.

Edited to add:

Apparently, affordability is not graded on a curve. In the original report referenced above, almost every state joined South Carolina in an “F” for affordability.  Probably for the same reasons, too.