New computer!

October 15th, 2012

Well, I picked up a new Thinkpad X200 Tablet. While it’s not the latest and greatest Thinkpad tablet, it’s my first computer other than an eeePC that has a solid state drive (SSD).

So how’s the SSD?  Fast.   That is all.

More later on the Ubuntu 12.04 installation process…

AT&T are idiots

June 19th, 2012

We get our internet service through AT&T.  Just got this in the inbox:

In a review of your account, we have found that you qualify for a bundle of services that may save you money.

For $64.99* a month for 12 months, your bundle will include:
(after instant rebate with 24-month DIRECTV® agreement; other charges apply)

Home phone service with unlimited local and long distance and our most popular calling features
* DIRECTV® ENTERTAINMENT Package with over 140 digital TV channels**
* Plus FREE SHOWTIME® for 3 months, a $38 value†

Notice what’s not there?  The only thing I actually use from AT&T.  Morons.

The effect of graded homework assignments on other grades

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.

In case of emergency …

February 29th, 2012

This sign appeared over the new emergency phone at work this morning.

Dail 911!

And remember, I work at a college.

If you ate at Taco Bell, go somewhere else!

June 13th, 2011

Here’s a sign posted on the inside of a Porta-John at the Ammon Blueberry Festival in Ammon, NC.

A deadly combination!

Imagine mixing anything in that list with Taco Bell.  The resulting explosion could level a town!

Happy birthday, Robert Bunsen!

March 31st, 2011

If you’ve visited Google today, you might have noticed that their logo looks a little strange.

That’s because it’s the 200th birthday of Robert Bunsen

Born in Gottingen, Germany, on March 31 1811, Robert Wilhelm Eberhard Bunsen was a prominent chemist in his day who discovered the elements caesium and rubidium and developed the Bunsen cell battery.

But he is best remembered for the distinctive gas burner he developed with his laboratory assistant Peter Desaga in 1854 and 1855 to study the colour spectrum of different heated elements.

…. the man behind the Bunsen burner!

Xournal: Want to number pages in a journal file?

March 31st, 2011

Want to number pages in your Xournal journal files?  If you’re using Xournal on a typical Linux distribution, you can try these Python scripts, which add or remove page numbers from the journal file itself.

They’re somewhat crude, so use them at your own risk.  They create a new file rather than overwriting the old one, so the risk in using these should be minimal.

They have gotten the job done for me for at least a  year now.


Any problems or suggested improvements?  Let me know!

On the Kindle

March 9th, 2011

I’ve had a Kindle for about 6 months now.  It’s a nice device, but it’s quite annoying that I can have new hardcover books shipped to me for 2/3 of the price of the Kindle edition.  Why should the Kindle book – which costs nothing to print, and nearly nothing to store and ship – cost 33% more than a full-size hardcover book?  (This ignores the much lower cost of the paperback – which is the edition most comparable to a Kindle edition, anyhow.)

Were the Kindle books a little more price competitive, I’d have probably bought about five times as many Kindle books as I have now.

Student sorting

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.

Weird Science

February 10th, 2011

Bask in the wrongness of this sign.

Is there anything on this sign that's correct? I do feel sad, though, for the poor student whose book was turned into a room. How is he going to study for his test?.

This one is somewhat embarrassing, since it was made by a staff or faculty member who should have been paying more attention.   If it was indeed made by a faculty member, I hope it wasn’t someone from the English department!