Archive for category Technology
Tuba for Sale
Posted by Dan in Technology on August 31, 2010
I’m selling my Cerveny CFB 653 F tuba. It has 5 valves (4+1), and is on the small side for an F tuba. It plays with a full resonant sound, even in the basement, which is surprising for a horn of its size. The horn has no dents, but a little wear and tear from regular use.
I played this horn on a doctoral recital and regularly as my “practice” tuba at home. It’s small enough to travel well, and big enough to be heard when you want to. It has generally good intonation, with the normal quirks one expects on an F tuba. The horn is mouthpiece sensitive; I found that the stainless steel Baer F mouthpiece makes this horn light up.
It includes a custom Glenn Cronkhite bag in blue and black. Those of you not familiar with his bags; it’s very sturdy and comfortable, with high density padding and wide straps. The bag will save you from a good deal of careless bumps that might go through a different bag, and you can sling it on your back and walk like a normal human being. It’s well-designed and constructed.
I’m selling because I’m down-sizing. I spent the summer up in the mountains with everything in storage. Now I’ve come back and said to myself, “Why do have all of this?” I might be looking for a different horn in the long run, but for now just the money in my pocket and the space in my bedroom is enough.
Item Discrimination
Posted by Dan in Education, Technology on April 27, 2010
For those who teach, testing is an integral part of what we do. We write test and homework, grade, evaluate, repeat. But at the end of the day, it is we as teachers who need to learn for/from the test.
One of the best ways to determine if a question on a test is a good one is to evaluate how many got it right or wrong, and who got it right or wrong. Two numbers are helpful in understanding the quality of a question: difficulty and discrimination. Difficulty is easy to arrive at: it’s simply the number of people who got it right, over the number of questions. If 9 out of ten got an item right, the difficulty index is .9. That number tells you whether a question is easy or difficult.
The second number, discrimination, is considerably more complicated to calculate, but also very valuable. Discrimination tells you if the question relates to performance on the rest of the test. In other words, did people who did well on the question do well on the test- did people who knew the material get this question right. You might be surprised what this number can tell you about a question.
In my Measurements of Musical Behavior Seminar with Dr Patti Sink we used something called the point-biserial correlation to determine discrimination. Calculating the discrimination this way is a big mess because it is conditional math. That is, some numbers get added if something else happens, but not otherwise. It’s easy to do by hand for small numbers of students and questions, but gets very hairy very quickly as the class or test grows. That is, unless you take advantage of the power of spreadsheets and macros.
Since I was a professional programmer for a while, I decided to help out my classmates and my community by writing a VBA macro to do the messy stuff automatically. I wrote a function called Discrim() that takes two ranges: one of item scores, and one of test scores to produce a discrimination value.
I present to you, the Discrimination Function for Excel, with instructions on loading it into your own spreadsheets.
This class has been a lot of fun, but also a great learning experience. I hope to use this knowledge to write better test, but also to improve my teaching, and helping those around me to understand the power of testing. Comments and feature requests are welcome!
The Music Notation Show-Down
Posted by Dan in Education, Music, Technology on December 12, 2009
As a teacher of music technology, I try to not teach the tool, but the concept. An important tool for any musician is a notation engine. There are two major players in the music notation market: Finale and Sibelius. Over the years both have developed into feature-rich, stable programs. There are a few different points of view about which one is best. I am not going to throw more wood on that fire though.
GarageBand
Posted by Dan in Technology on November 14, 2009
I’m teaching music technology at UNCG, so I decided to have a little fun with my class for this next unit.
GarageBand is a MIDI sequencing program and audio editor. Basically, it allows you to “compose” music by layering and arranging recorded and digital sounds. For class, I performed a demonstration of the software by inviting everyone in class up over my shoulder as I constructed this, my magnum opus:
I created this live in front of my class. I set up a loop with some bass and drums, talked about various aspects of the software and and recorded chunks of my monologue. I also grabbed a MIDI file off the desktop (Thank you Mozart!) and dropped it in real-time to show how flexible the software is. I applied some effects, built a groovy background and did some splicing, and BOOM. There we are.
It’s not art, but it’s a sign of how powerful music technology has become. It used to take a room full of very expensive equipment and many hours to do anything like this. Now the threshold has been lowered. Some people do this for a living. I do it so my students think I’m a nerd.
The Free Computer Lab
Posted by Dan in Education, Technology on October 7, 2009
As a teacher I am always looking for the best way to teach my students, and the most useful skills/information for them to learn. My experiences as a teacher at 5 different universities has led me to a few conclusions. Read the rest of this entry »