28 February 2008

Hurt feelings? Are you kidding me?

Hurt feelingsThis story is weird.

The Minnesota Soybean Growers Association and the Minnesota Soybean Research and Promotion Council funded research on biofuels.

The research resulting from this came out in Science, about as high-profile and as prestigious as scientific research gets, indicating that biofuels made the carbon emission situation worse rather than better.

The organizations pull their funding.

"The university hurt the farmers' feelings, OK? That's probably the best way to say it," said Jim Palmer, executive director of the two groups.
Wow. Just... wow. "Kill the messenger," anyone?

There seems to be a misunderstanding about the difference between giving money to researchers and giving money to, say, PR firms. Researchers have the obligation to publish their results regardless who paid the money.

Can the people in these agencies not see how this kind of action would tempt researchers to do bad science? To withhold information? How taking this action makes them look even worse?

I'm totally gobsmacked. Again, just... wow.

27 February 2008

New namesake?

SmartI am in the process of buying a new car. I wanted to get something as fuel efficient as possible. So I'll be getting one of the first Smart fortwo cars released in the U.S. (pictured). These have been in Europe for a decade. I first became aware of Smart when I saw one on Top Gear. They described the Smart cars as being marketed as a "fashion accessory," but then road tested in Birtish back roads, and gave it a positive review as a sports car. I used to have an MG Midget, and it seemed to me that the Smart was sort of a spiritual descendant of the Midget.

How I wish I could go further. But I can't. The sad fact is, I can't afford a hybrid. I tried to buy one when I first moved to the U.S., and the bank wouldn't loan me the money, and I'm not in a much better position to buy one now.

ZennThe Zenn (left) is a fully electric car made in Canada, and its name means "zero emissions, no noise." Weirdly, it's very difficult to buy in Canada, as Rick Mercer discovered. It actually can be bought in many places in the U.S. -- but Texas isn't one of them. Sigh. But even if it was sold in Texas, I still couldn't buy one. Because I'm an apartment owner, I would have no place to plug it in.

Two things occurred to me about this. One is how dependent our choices are on available infrastructure. The second is how Canada -- and the northern states -- might have a huge advantage in moving to electric cars faster than someplace like the U.S. Canadians have been plugging in their cars forever. This amused people from more southern climes, who laughed at the electric plugs dangling from the radiator grille. because it gets so cold in winters that engine need block heaters to prevent them from freezing. Since Canada has at least some infrastructure that provides electricity for cars (at least places where people would park them for long period during winter), it might facilitate the influx of electric cars.

If politicians would just wise up and let them sell some.

26 February 2008

A good day for the world

The Encyclopedia of Life has finally moved past the preview stage.

Good luck at trying to access the page. It's been very slow today, the server no doubt reeling under the load of people who have been eagerly awaiting it.

This particular database spring from a TED prize for biologist E.O. Wilson, shown below.

Not to belittle Wilson's enormous contribution for this project, but I do need to say that kind of project has been on the minds of a lot of people for a long time. There are various taxonomic databases out there. The Tree of Life was probably the first major one, and Wikispecies is another. And those projects have been very valuable, but I think it's fair to say they haven't revolutionized the science the way that GenBank did for DNA or that Wikipedia did for general knowledge.

Hopefully, Encyclopedia of Life can be that transformative resource.

It's interesting to compare how different databases look. Let's take spiny sand crabs, Blepharipoda occidentalis, the main species I work with for my doctorate. In Tree of Life, there isn't a listing for the species or even the genus. Just a species name in Wikispecies. Like the Tree of Life, I can't even get close to "my" sand crab species in the Encyclopedia of Life yet, but I think you get a sense of the ambitious nature of these projects.

The future of teaching

TED talks have shown up in this blog a lot, because they are just so good. Below, Chris Anderson, who runs that conference, is interviewed below, and has a lot of interesting things to say.

He talks a little about the success of the TED talks, using Hans Rosling as an example (see his now classic presentations here and here), makes these interesting observations:
When you think about what that means for the role of teacher in our society, I think it's really interesting. The role of teacher now, in the last couple of decades, has been one where everyone says, "Oh yes, that's a terribly important job, passing on knowledge to the next generation," but no one of ambition, very few people of ambition, do it. Because it pays so poorly and it's hard.

That's changing, because the economics of the internet have dropped... in the last two years, it's spectacular what's happened. The de facto cost of a teacher, live, filmed, giving a talk, where you can see them in their full glory, giving, being inspiring, sharing their ideas, and so forth... The cost of transferring that to someone on the other side of the world, two or three years ago, was two dollars. One transfer, person to person. Because you would have to burn it on a DVD and mail it to them. Even at scale, the incremental cost of adding on a person would be two dollars. So, of course, it didn't happen.

Broadband internet, the online video revolution, you know, it's not just about YouTube. For these teachers as well, the de facto cost of doing that same thing has fallen to about a penny. That's so cheap that a sponsor will pick up the cost. So it's free.

So that means, we're just seeing, we're on the verge of the really early stages of this, an explosion of knowledge and the transformation of what it means to be a great teacher. So instead of going into teaching thinking, "Oh, I'm going to influence 30 people a year if I'm lucky," some teachers, at any rate, can go into teaching knowing that if they're great, they will change the world. They will have a global audience in the millions.
A long time ago, I read a comment on why university professors were often poor teachers. A mediocre researcher might be known around the world, but the reputation of the very best teacher stops at the edge of campus.

Sad, but often true. Indeed, I can only think of one professor who had a reputation for teaching a brilliant class. Don Abbott. And I do admit that my Ph.D. supervisor and some of my friends took the classes for which he was famous, but that is not how I learned of his reputation as a phenomenal teacher. So great was his reputation for his instruction that a book was published that was based in large part on notes from that class and included work from students.

But Anderson is right: now, the best lecturers can gain fame as being a superb lecturer. Walter Lewin provides another superb example.

25 February 2008

What wasn't reported most places

David BaltimoreThe American Association for the Advancement of Science (often referred to verbally as "Triple A S") had it annual conference last week. I heard a lot of reports back from the conference on various podcasts, but interesting, only the Australian Science Show mentioned the searing commentary of outgoing AAAS president, David Baltimore (pictured):
Since 2001 I've lived the life of denial. I've denied responsibility for the actions of America. I've denied that President Bush speaks for, represents, my country. I have held my breath awaiting new inhabitants in Washington who will again be moral, thoughtful, balanced people who I consider true Americans.
And that's just the beginning. More of Baltimore's comments can be found here.

What I find interesting is not Baltimore's criticism of President Bush, but that nobody mentioned it. Here's the president what might be the biggest scientific society in the world taking a swipe at the president -- and (almost) nobody notices.

If the leader of a major labour union or other group said what Baltimore said at a major gathering of their members, would they get attention? Probably. But scientists, it seems, can safely be ignored.

23 February 2008

Job season

I bet a lot of people outside universities don't know that universities have a job season, when the department usually has candidates visiting the campus. Ours has crept up over time. I interviewed in April, but now it tends to be February (and upper administration would like it to be earlier if we could).

We have interviewed for multiple positions each year since I've been here. So that's usually a minimum of four job candidates to meet, and often much more, in a few short weeks.

And I'm also in the thick of recruiting for the second year of my REU program.

So if I'm blogging less, those could be why.

19 February 2008

Ban tech, or, Why I am such a hypocrite

laptopsI am a geek, and I enjoy technology. I use technology a lot in my classes.

So why have I started asking students to put away their laptops in my classes this semester?

First, to remove temptation. Now that I finally have my Pocket PC working somewhat well, I've learned about the lure that such connectivity has. I was in meeting myself with my Pocket PC, and found myself realizing, "Wait. Why am I messing with this instead of listening to the speaker?" Our classrooms all have wireless internet connections. When a lecture drags a bit for a moment or two, the temptation to zip over to check email, update Facebook, look at YouTube is strong. I say this not as criticism, but as someone who hears the siren call myself. I want students to think when they're in my class, and I think having a laptop with a live internet connection detracts from focusing on the task at hand.

Second, I want to see faces. This is something I doubt students would think of, because they generally don't physically see the classroom from an instructor's perspective. I don't mean that psychologically, I mean they literally don't stand and see the room from the front. There is something very psychologically powerful about looking around a room, and seeing people looking back. When there's a laptop, people tend to be looking at the screen. And in a room with a bit of a slant, you can barely see the faces at all, and it becomes like lecturing to a series of bricks.

So no laptops in my classes. For now.

18 February 2008

They say missing glitches, I say proof

An extensive list of glitches Johnny Quest does not list Dr. Quest talking to a trapped native in English and expecting an answer. Which I guess must mean that everyone does understand English if you say it slowly enough.

16 February 2008

Lecturing doesn't matter

There's an episode of the classic television series Johnny Quest ("Treasure of the Temple," I think) in which Dr. Benton Quest, in some far off exotic locale, comes across an unfortunate local who has been staked and tied, spread-eagled, to the ground. The local speaks urgently to Dr. Quest in his native tongue.

The brilliant scientist says, slowly, deliberately, and loudly, "WHO... DID THIS... TO YOU?"

After all, everyone understands English if you just say it loud enough.

A lot of professors, though, do to their students much the same thing as Dr. Quest did to the native. They think if they can just say things more clearly, their student will understand. I've had many conversations with colleagues who bemoan their students' poor performance on an exam, and say, "But I told them..." They think that if they can become a better lecturer, explain things more clearly, that students will understand better and retain more.

For instance, "Students didn't do well on this material, but I really didn't stress its importance enough. So next I'll be very clear to tell them this is a big part of the exam, and they need to study it."

Unfortunately, this may be completely misguided.

When I was at the Society for Integrative and Comparative Biology meeting back in January, there was a session on education in evolution. Craig Nelson talked about data that has been gathering in physics education for a good while now. The data from physics education indicates there is no such thing as a good lecturer.

Students learn about the same amount regardless of the lecturer when the traditional lecture format is used.

The thing that actually starts to improve student scores and understanding are not better lectures. Better lectures are like saying, "WHO... DID THIS... TO YOU?" to the native even slower and louder. Instead of staying with traditional lectures, instructors need to incorporate other techniques that allow and require students to develop some of the knowledge themselves. Having students listen just doesn't cut it.

Yet very few professors seem willing to deviate from standard lectures and rebuild their classes from the ground up. Even to take advantage of something fairly simple, like clickers.

15 February 2008

Tests are a chance to learn

ResearchBlogging.orgTest early and test often.

That the message of a new paper in Science on learning by Karpicke and Roediger. This is an important paper for educators, as it claims to show that you don't learn as much just studying for a test as you do actually doing tests. That is, testing is more effective than studying.

KaaTo test this, they taught students a little Swahili. Students had to remember that "kaa" meant "crab," for example. They would see the Swahili word and its English definition on a computer screen for a few seconds, during which they would have to try committing it to memory. This was the "study" condition.

In the "test" condition, students were shown a Swahili word on a computer screen and had to type in the English word.

In every case, the students would do a round of studying, then a round of testing. In some conditions, the researchers set thing up so that students were only tested for words that they previously missed. This makes intuitive sense -- if you know something, why study it again?

The researchers varied how many pairs of words students got in each bout. Sometimes, they would get 40; sometimes, they would get less than 10. This does mean that the total number of trials -- i.e., individual pairs of words -- varied.

After eight rounds of studying and testing, students had this task cold. They were perfect. 100% recall in all experimental conditions.

The researchers asked each student how well they thought they would do on the final test; students reckoned they get about half the words. Then the students went away for a week, and came back for a final test.

If the real learning is going on during studying, you would expect to see a strong correlation with the number of study trials and student performance.

The effects are huge.

Students who were tested a lot over everything recall about 32 of the words (80%) -- more than double those who just studied, who recalled about 14 words. There's not even any overlap in the conditions. That is, the worst person who was tested on everything still did better than the best person who only studied.

That, my friends, is what my stats professor, John Vokey, called significant by the I.O.T., short for inter-ocular test. It's so bloody obvious it hits you right between the eyes.

At first, I thought this could be a simple case of distributed learning. It's been shown many times that studying a little over a long period of time is much more effective than studying a lot all at once. But this shows something different. It shows that encoding information over and over again isn't very helpful on its own, because there's another element going on: retrieval.

To use a wacky Zen metaphor, it doesn't matter how much you deposit into your bank account if your ATM card is busted and you can't withdraw any cash.

It is astonishing that an effect this powerful hasn't been recognized. And this clearly has strong implications for how we should teach students. This could well be a reason why clickers work. Why "just in time" quizzes work. Not just because students are getting more study or more exposure to information, but because they are being tested more, and they get better at retrieving information.

If I weren't constrained by already telling my students how my classes would work this semester, I would be retooling my classes right now to include even more tests.


Karpicke, J.D., Roediger, H.L. (2008). The Critical Importance of Retrieval for Learning. Science, 319(5865), 966-968. DOI: 10.1126/science.1152408

14 February 2008

Deep research

Wikipedia exists.

A lot of teachers seem to be in denial about this.

University instructors' usual directive to students concerning Wikipedia is, "Don't use it." Not very much explanation, just a command. But I know that for me personally, when I need to find out about a few facts, what do I do? I type stuff into a search engine that will probably lead me to... Wikipedia. I do not think I am alone or unusual in this regard.

The difference between instructors and students is that the instructors don't stop at Wikipedia.

Rather than simple prohibition of using Wikipedia (which many students ignore), instructors need to think hard about how we can teach students how to research like a professional. What constitutes good evidence? What can you trust? Why should they used PubMed instead of Google? Or Google Scholar instead of Google's front page? How do you tell if a journal is peer-reviewed? Why is peer review the gold standard?

Instead of giving students direct instruction in these matters, the tendency is to sort of roll it into other classes and hope they pick it up as we go. But why not take the bull by the horns and try to get them to research like professionals do? The current situation is a little like telling them to drive to another city but forgetting to tell them how to use the car.

I don't think many university instructors have really come to terms with the existence of search engines and online information. And perhaps it's not surprising, because most classes have a hard enough time simply getting students past new terms and their definitions. Dealing with strategies for gaining new knowledge, and then evaluating that knowledge, is much more general and subtle.


Just an quick update.

13 February 2008

The Zen of Presentations, Part 18: The hardest words

Australian PM Kevin RuddSome presentations are harder than others. The type Australian Prime Minster Kevin Rudd just delivered what might be one of the hardest of all: a serious and sincere apology.

When I lived in Australia, I could not help but be struck by the many parallels with my native Canada. One of the unfortunate similarities has been the treatment of indigenous peoples: the First Nations in Canada, and the aboriginals in Australia. The policy for years in both countries was to destroy the native culture and assimilate it. So many things were so badly wrong, it's hard to know where to begin.

Rudd formally acknowledged how wrong those polices were. The speech is over 25 minutes, but to his credit, Rudd gets to the important point in the first few minutes.

We say sorry.

The power of apology should never be underestimated.

Rudd's delivery is not animated or passionate. He reads word for word from his prepared text. In many ways, it is not a very good delivery.

After saying sorry, the speech lapses into some bland generalities that could be heard in almost any political speech. Moving forward, great nation, equal partners, all Australians, and so on.

But Rudd then brings it back with a specific, concrete example of one woman, Nanna Nungala Fejo, and her story. How she was taken from her family by the government. Her message for Rudd to convey: "All mothers are important." Powerful.

Rudd even gets in some wistful humour without seeming disrespectful when he describes how aboriginals were to be raised in Christianity:

A few years later, government policy changed. Now the children would be handed over to the missions to be cared for by the churches. But which church would care for them?

The kids were simply told to line up in three lines. Nanna Fejo and her sister stood in the middle line, her older brother and cousin on her left. Those on the left were told that they had become Catholics, those in the middle Methodists and those on the right Church of England.

That is how the complex questions of post-reformation theology were resolved in the Australian outback in the 1930s.

Rudd also uses a little dry understatement to good effect:

But let us remember the fact that the forced removal of Aboriginal children was happening as late as the early 1970s. The 1970s is not exactly a point in remote antiquity.

Rudd reiterates the words people had been waiting years to hear:

To the stolen generations, I say the following: as Prime Minister of Australia, I am sorry.

On behalf of the Government of Australia, I am sorry.

On behalf of the Parliament of Australia, I am sorry.

Rudd's speech then goes on to look at the future. As Rudd talks about new policies, it again becomes a fairly generic political speech in many ways.

There's no question of the importance of Rudd's speech, because of the political will it represents and the desire to admit wrongs. But it's worth looking at because it has a higher goal than most presentations typically have. Most presentations are meant at some level, to be entertaining, because that's how we engage people. But in talks like Rudd's, attempting to entertain would be totally inappropriate. The task becomes much more demanding. The only option is utter sincerity. You must really mean every word you say. And while there is much that I can nitpick in Rudd's presentation and the text of his speech, I do not doubt his sincerity. Rudd's message of apology and forgiveness is too powerful to be capsized by the details of his delivery.

Well done, sir. Well done.

A video of Rudd speech can be found here. More about the response to Rudd's speech can be read here.

12 February 2008

But wait for 2009

Darwin in 1840Happy Darwin Day!

Next year is the 200th anniversary of Darwin's birth and the 150th of his best known book. I hope to do something a little more substantial than a blog post next year.

Urbanization and biology education

Lewis Black's take on creationism is not, shall we say, work friendly. Those who are offended by profanity will be offended by this.

Seeing this made me think about something, though. Fossils. Where I grew up in southern Manitoba and southern Alberta, there were a fair number of fossils to be found if you looked around. Manitoba used to be a shallow inland sea, so there were lots of shell fossils. Quite a few people had gravel parking lots in the town I grew up in, and sometimes I would look through rock after rock in a parking lot with that obsessiveness that kids have, and occasionally would find something.

Alberta's fossil riches are really well known because of Dinosaur Province Park and the Tyrrell Museum, but I picked through limestone in Frank Slide, too. Limestone is great for fossils.

I had direct experience with finding fossils as part of my general running around in the countryside as a kid. And in talking to my colleagues, a lot of them seemed to have that same sort of experience with the outdoors when they were kids.

This got me thinking about whether part of the reason so many people express doubts over evolution is not just because of religious fundamentalism (which undoubtedly is big), but because more and more people are growing up in urban environments were they have less and less contact with anything biological. Even setting aside the urban thing, I suspect that more and more parents so closely regulate and monitor their kid's every move that there's a lot less time for kids to go mucking about on their own in the outdoors environments they do have available to them. Woodlots in parks, say.

There's a huge difference between reading about fossils and finding them yourself. It stops being theoretical. Now it's a real thing that you might want to have some explanation for.

And since seeing Black, I really want to find a fossil that I can carry around in my pocket. Maybe on my keychain. Maybe a trilobite or a small ammonite, but even a simple shell would do. So that, when necessary, in discussion on evolution, I can pull it out, point to it, and say, "Fossil."

09 February 2008

Triage versus health

Was having an informal discussion about some of our lab with colleagues and some teaching assistants. The teaching assistants were talking about students not showing up for quizzes in the lab, and so on. One of my colleagues said, "That's not our problem."

Of course, what was meant was, "That's not our immediate problem."

My colleague was thinking about the immediate needs of running a lab: Are there adequate supplies? Do the teaching assistants have the information they need? Immediate, high-priority needs.

Like so many things, there's a hierarchy of needs. You can't worry about your relationship with your partners or parents (long-term, low priority need) if you don't have food and shelter (immediate, high priority need).

Unfortunately, trying to deal with those immediate needs means that we don't have too much opportunity to spend time discussing the sorts of things that we ultimately want to be talking about. How do we make students eager to learn more? How do we give students tools to learn in a way that works for them?

07 February 2008


The title of professor doesn't hold a lot of resonance with me. Someone who professes. Eh.

But I am very happy and proud to be a doctor.

Someone who makes people better.

Usually, people think of that in narrow physical terms: healing the ill. But I'd like to think you can also make people better by education. By creating ideas. Maybe by inspiring people, if you're lucky.

(This post draws directly from a line by Russell T Davies in "The Sound of Drums" in series 3 of Doctor Who. Thanks, Russell!)

06 February 2008

Why do it again?

I'm toying with the idea of re-writing the GRE.

The GRE is a standard test required by many schools to enter their graduate and doctoral programs. When I took it way back to enter graduate school, my good scores really tipped the scales in my favor in admissions.

I'm not thinking about going back for another degree, but I'm considering retaking for a few reasons. Most importantly, if I scored well enough on it, I could become an instructor for some of the agencies that offer GRE preparation classes. Our students could really benefit from GRE prep classes, and having someone on-site who could teach them might help. Plus, I could earn a little extra cash.

Plus, there's the masochistic question. "Do I still have 'it'?"

05 February 2008

Evidence based teaching

Academic scientists are both typically supposed to be both researchers and teachers. Scientists pride themselves on looking for data and evidence in research. So it's interesting that so few scientists look at data and evidence in teaching.

There's very little data in biology instructions on whether textbooks actually help students. I very rarely see discussions like, "I found a 5% increase in comprehension when I used this teaching technique." So while scientific research makes progress and improves, scientific teaching has stayed pretty much the same: Talk a few times times a week, test once a month.

I wonder if it's a matter of, "I learned okay listening to lectures, so it's okay for my students."

04 February 2008

Motives for teaching

Today, Seth Godin writes:
People take action (mostly) based on one of three emotions:

Seth is, as usual, talking about marketing. But he could also be talking about teaching.

Bad teachers motivate students by fear. "Look to the left. Look to the right. One of you will be gone by mid-semester."

Good teachers motivate students by hope. "If you work and study right, you will get a good mark in this class."

The really extraordinary teachers motivate students by love. They inspire students to become passionate about the subject at hand, and the students become self-motivated to learn out of curiosity and pure enjoyment.

Teaching by fear is easy. Teaching by love is damn hard.

Not surprising that so many students have curiosity beaten out of them, when they have primarily been motivated by fear.

M.D. vs. Ph.D.

Thor #2 excerpt
Joe Straczynski reminds us of how society values different doctorates.

From Thor #2, written by J. Michael Straczynski, art by Olivier Coipel, published by Marvel.

02 February 2008

Dirty water

ResearchBlogging.orgJohnson, P., Chase, J., Dosch, K., Hartson, R., Gross, J., Larson, D., Sutherland, D., & Carpenter, S. (2007). Aquatic eutrophication promotes pathogenic infection in amphibians Proceedings of the National Academy of Sciences, 104 (40), 15781-15786 DOI: 10.1073/pnas.0707763104

You might notice that your local lake or pond or river is a lot less clear than it used to be. More green, more brown, more algae growing on the rocks. This is eutrophication.

How much algae can grow in freshwater is typically limited by how much available nitrogen or phosphorus there is in the water. Human have been putting in a lot more of these chemicals into watersheds for lots of reasons. They're in soaps, for instance. More nutrients, more algae. More algae, more things that eat the alage, like snails. More snails, fewer frogs.

Wait. Fewer frogs? That's what this paper from P.T.J. Johnson and colleagues attempts to show.

The missing link in the little story is a parasite, a trematode fluke named Ribeiroia ondatrae (right). This parasite has a complex life cycle requiring three hosts: snails, frogs, and birds. It initially infects snails, castrating them when they do so.

They next infect tadpoles of frogs. This infection doesn't kill the tadpole or the adult frog, but when the infection is heavy, they do cause quite serious limb deformities: extra appendages, and so forth.

The final stages of this life cycle weren't studied by this paper, but it seems that the limb deformations would make the frogs more likely to be eaten by birds, which is the final host for this parasite and will be where the trematodes reproduce sexually. They pass out in the feces of the bird, back into water to infect more snails.

So when you have eutrophication generating more snails (more food for them), there's more hosts for the parasites, which then go on to really hammer the tadpoles, which are not benefiting quite so much from all the extra algae.

The downsides to this study are that it covers a very short time span: only two months. And these are artificially created pools the experimenters set up, so they're really only documenting the establishment of a small ecosystem. It's much harder to tell what a final, steady state condition might be. Considering that the trematodes castrate the snails before they infect tadpoles, it's possible that the big differences they see between low, medium, and high levels of water eutrophication in tadpole infection might get smoothed out somewhat over time. That is, as the parasite population jumps, the snail population might crash, removing some of the pressure on the tadpoles.

A very clean, straightforward experiment, but, nothing terribly surprising here. It probably is only published in a major journal because of the concerns over amphibian decline. If one of the hosts was something other than an amphibian, it might not be have been published in PNAS.

The Zen of Presentations, Part 17: Cutting the cord

Wireless remoteOne of the most useful tools for anyone using slides on a computer screen is a good wireless remote. They free you from a lectern, allowing for a much more dynamic and mobile talk.

I recently was given a gift of a new wireless remote (pictured). I don't want to turn this into a review / ad for this particular product, but I'm very happy with this one so far, and it gives me a good opportunity to talk about some of the different kinds of wireless remotes for slideware.

I've used a few different remotes, and they vary dramatically in their shape and feel. Some are wide, some are round, some are slender. Finding one with the right "feel" is probably a very personal thing. You should probably look to see if you can borrow some and test a few before buying. (Unfortunately, most remotes get stuck in those impossible to open packages, so you can't handle them.)

Wireless remote pluginsSimilarly, another thing that you often can't see in the packages are how big the receiver that plugs into the USB port is. Again, these differ a lot from one to the other. My old one (top right), from a Targus presenter, was quite wide and chunky, which typically meant that I needed a hub or a short extension cable to plug in anything else along with the remote. (Chunky, fat USB receivers seem to be a feature of pretty much every Targus remote, alas.) My new one not only has a smaller profile, but has a slot where the receiver fits into inside the remote itself, so the receiver is less likely to get lost.

Surprisingly, a feature I have yet to see (or perhaps I've seen once) is an integrated flash drive and radio plug-in. It would seem to me to be logical to combine these two so that you would only have one thing to plug into the USB port, not two.

Pretty much every remote has a laser pointer in it, but they can very somewhat in terms of their brightness. They're almost all red, although I see green ones are just starting to become available. Green lasers are much brighter, but they are tricker to find in stores, more expensive, and probably has fewer features.

Besides backwards and forwards, remote presenters have a wide range of other features.

The feature that attracted me to my new presenter is that it has a built-in timer. I've written before about how important it is to stay on time, and with this presenter, you almost have no excuse. When you start, you pick a time, and the remote vibrates when you have five minutes left, and again at two minutes. Brilliant. It's not perfect -- it only goes up in increments of 5 minutes, for example -- but it's so useful that it's amazing that more remotes haven't copied this idea.

Some can act like a mouse, allowing you to move the cursor around screen. The ones I've tried, however, are so painful to navigate with that I would invariably walk back to the lectern and just use the mouse instead of trying to use the mouse mode int the remote. One from Targus that has a little trackball (like old school Centipede!) that might be a little more manageable.

I've seen at least one remote that has a built-in voice recorder (Targus again). This might be an attractive feature, provided that you never put your remote down! I find that I occasionally set mine down to draw on a board or gesture with both hands. I've taken to recording my lectures for podcasting, so I think this might be another feature that could be built in more often.

Many do not have an off switch, which is fine if it sits on your desk. Perhaps not so good if you travel, and have to stash it in luggage or other places where the buttons might get pressed accidentally.

Few have a battery indicator. Again, this is a nice feature of my new presenter. Many do not, potentially leaving you stuck without warning in the middle of a presentation. Although, in fairness, most remotes will probably last for years on a single set of batteries.

And the list is nowhere near done! Can it start and end a presentation? Blank a screen? Control sound volume?

For something that is usually going to have a simple function -- next slide, repeat until done -- there are a lot of details to consider, and shopping around is definitely worth it.