Sunday, April 27, 2008

Concrete or Abstract?

Concrete examples or abstract examples? I have struggled with this issue in lectures and in writing. Usually, I opt for concrete example first followed by the more general, abstract case.

My rationale for this approach has been the results from the Wason Selection task. That logical problem (If P then Q, if Not P then Not Q is the solution to both cases) is solved much, much more often in its concrete form (~75% of the time) than in its abstract form (~5% of the time). Here is a site that explains this problem.

However, recent research from the Ohio State University (as reported in the New York Times) in mathematics education suggests that teaching the abstract first is far superior to teaching the concrete first in mathematics problems. This research was recently reported in the journal Science. The authors are Jennifer A. Kaminski, Vladimir M. Sloutsky, and Andrew F. Heckler.

To me, the discrepancy between the Wason Selection data and the Kaminski et. al data indicates that further research is needed. I agree that flying by the seat of one's pants is not a good idea here. It would be nice for teachers to know, once and for all, which strategy is best.

By the way, I sometimes use an abstract first strategy. Recall my earlier post on the Mastermind game. There I use an abstract first-first strategy to teach about main effects and interactions.

Wednesday, April 16, 2008

The Kilo in Crisis

Here's a recent story from the Los Angeles Times.

It tells about how the various standard kilograms around the world are no longer standard. When these kilogram weights were checked against the standard kilogram in Paris (made of platinum-iridium), they no longer weighed the same.

Here is a link to a picture of the standard kilogram. The kilogram is the last physical standard that is still defined in reference to a physical object. Originally, the kilogram was defined as the mass of a cube of water with sides equal to 10 centimeters. No one knows why the standard kilograms are losing weight, but the loss has led to a search for alternative standards. One approach is to construct a very sensitive magnetic balance, another is to actually count the atoms of a particular element.

All other standard units are defined in other ways, without reference to physical objects. The National Institute of Standards and Technology (NIST) defines the other standards. CLICK HERE to see all of their definitions and the historical context that led to the definitions. The NIST's definitions of the meter, the second, and the candela are reproduced below.

"The meter is the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second." Originally, the meter was defined as 1/10,000,000 of a quarter of the earth’s circumference.

"The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the Cesium 133 atom." Originally, the second was defined as 1/86,400 of the mean solar day.

"The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian." Originally, the candela was the light given off by a standard candle (candela is Latin for candle).

One of the fundamentals of science is measurement. As sciences became more and more developed, the need for precision became more acute. So, redefining the kilogram is a real crisis is science.

Tuesday, April 8, 2008

2009 Regional Psychology Association Meetings

In chapter 12 we discuss scientific meetings and more specifically, the meetings of the regional psychology associations.

Martha Boneau at APA just sent me the 2009 dates and locations of those meetings. Here they are:

2009 Meetings of the Regional Psychological Associations (sorted by date)

Feb 18-21, 2009
Southeastern Psychological Association (SEPA)
New Orleans, LA
http://www.sepaonline.com/

March 5-8, 2009
Eastern Psychological Association (EPA)
Pittsburgh, PA
http://www.easternpsychological.org/

April 2-4, 2009
Southwestern Psychological Association (SWPA)
San Antonio, TX
https://www.swpsych.org/

April 16-18, 2009
Rocky Mountain Psychological Association (RMPA)
Albuquerque, NM
http://www.rockymountainpsych.org/

April 23-26, 2009
Western Psychological Association (WPA)
Portland, OR
http://www.westernpsych.org/

April 30 - May 2, 2009
Midwestern Psychological Association (MPA)
Chicago, IL
http://www.midwesternpsych.org/

Oct 9-10, 2009
New England Psychological Association (NEPA)
Worcester, MA
http://www.nepa-info.org/

Statistics: Then and Now

I must in a retrospective and nostalgic mood. I remember how I used to have to compute statistics back in graduate school. During my first year, I recall when the statistics class first walked into the department's calculator room. Imagine a room full of calculators that looked like the one below.

This is a Monroe brand rotary calculator. I doubt that I could use one today, but back then I learned to be pretty good at it. The calculations had to be recorded on large pieces of paper. I still have some of those calculations in my files. (But then, I also still have my first grade report cards too. I'm a bit of a pack rat.)

On the first day in the calculator room, we were all warned not to divide by zero. Recall that dividing any number by zero yields infinity. If a Monroe calculator was set to divide by zero, it would continue to chug until someone pulled the plug.

Before I went to graduate school, I invested in my own calculator, a Texas Instruments SR-10 model. It cost me $149, plus tax. The beauty of the SR-10, was that it could calculate square roots. Interestingly, I had to return my first SR-10; it had a missing decimal point in the display between the 1,000s and 10,000s. My roommate, an engineer, and I discovered the faulty decimal display when I could not figure out why my homework problem kept coming out wrong. Here is a picture of the SR-10. Note the square root button. The display was red LEDs. Here's a link to more information on the SR-10.

My roommate, the engineer, was an early adopter of a more expensive early calculator, the HP-35. He paid nearly $400 for it. The HP calculators used a different method for accepting numerical input: RPN or reverse Polish notation. I never liked having to use that system because it required me to learn a new way to think about math problems. Here is a link to a page on the HP-35.

The Texas Instrument calculators, on the other hand, used familiar algebraic rules for inputting data. I'm sure that alone led to many sales compared to the HP family.

Today, these calculator are only seen in museums. Statistical calculators, too, appeared and are still available today, but at much cheaper prices. Most statistical calculations now, however, are made on specific computer applications. SPSS, SAS, R, and Statistica are commonly used statistical computer applications.

It's interesting to me how quickly students (and faculty) adapt to new technologies. However, it seems that students are remarkably blasé about past technologies. So, I guess part of my job is to remind them.

Friday, April 4, 2008

Taking Care of Rats and Pigeons: 1972-3

My last post reminded me of my undergraduate days and when I had the responsibility for the rat and pigeon lab at the University of Baltimore. The lab is no more, and that space is now an administrator's office, seems fair :-)

Our lab housed about a dozen albino rats and half as many pigeons. I was (and still am) allergic to rat dander, so I had to wear a filter mask. My job was to feed and water the animals and to clean up after them. For that, I earned minimum wage which was $2.40 an hour.

A couple of incidents still come to mind. One was the only day I was ever bitten by a rat. That happened on the day the experimental psychology class first came to meet their rats. In retrospect, it seems obvious what happened. The rats were all nervous, probably in response to the students' own anxiety, and one took it out on me. He got my left index finger. Fortunately, his upper teeth hit my fingernail, so only his lower teeth broke the skin. For a few seconds, I had a half pound white rat attached to my finger while blood streamed everywhere. After he let go and fell, I caught him and put him back in his cage. Then, I got some first aid.

The other incident involved a pigeon. I learned how to catch a loose pigeon. The lab was windowless by design, so I could control the amount of light in the room. So, one of the pigeons got loose one day and was flying around the room. Fortunately, I remembered my mentor's advice, "Wait for him to land, then turn out the lights, sneak up on him and grab him." So, I watched and when the pigeon landed on the lens of the overhead projector, I turned off the lights and slowly approached. Slowly, I placed my hands around where I imagined him to be and closed the distance between dexter and sinister (my right and left hands for the Latin-impaired) and grabbed him. Back to the light switch, one pigeon nabbed.

Pigeons, possessing eyes with cones only, are effectively night blind. So, once the lights go out they are very unlikely to move. Ahh, the good? old days.

Thursday, April 3, 2008

Animal Research: Then and Now

You may have noticed that we say very little about animal research in our text. That is strange because we both come from animal research backgrounds. Much has changed in animal research over the course of our careers. There is much less animal research going on in psychology than there was 40 years ago.

There are several reasons why animal research is less common now. The most obvious, perhaps, is the rise of the animal rights community, notably PETA (People for the Ethical Treatment of Animals and similar groups. I attended the 1990 APA convention where PETA exhibited a float outside of the Washington Hilton Hotel depicting the horrors of animal research. At that same meeting, demonstrators disrupted presentations, including one by Neil Miller at which I was in the audience.

Another reason for the decline of animal research in psychology is money and still another is more outside regulation. The price of animals has risen as has the price of housing and caring for them. In addition, new regulations (which we cover in chapter 3) have made it more difficult to maintain existing animal facilities and nearly impossible to start new ones.

Sally Boysen's chimpanzee research is an apt example. (See this link to Scientific American Frontiers for more information.) Her research, valuable as it was, ended up a victim to costs, regulations, and more. Her university closed down the lab and sent the animals to Texas. Boysen chained herself to the door of the lab before the move, but that action, dramatic as it was, changed nothing. Here is a news story about the closing of her lab.

The impetus for this post, however, is an upcoming book: The Animal Research War by P. Michael Conn and James V. Parker, to be published by Palgrave Macmillan in May 2008. Here is a link to the publisher's page about that book. Here is an link to an excerpt, you may have to register (for free) before being allowed to read it. If you are interested in animal research, I recommend the excerpt highly.

All things change, including psychology. Animal behavioral research is still valuable, I think. Certainly, the assault from PETA and others forced changes too. Some of those changes were probably needed. For instance, undergraduates taking physiological psychology courses probably don't need to sacrifice and dissect a rat's brain in order to learn how brains work. Obviously, graduate students in physiological psychology do need to learn such techniques. The winds of change blow and we usually don't know what kinds of changes they will bring. Less animal research in psychology was one of them however.