Category Archives: Education

Justified

I was asked on Twitter if I could clarify my views on text justification for conference posters, but decided I couldn’t come up with a good 140 character response. So here you go:

fabric-postersI recommend left-justified research posters for several reasons. First, I read in some typography/readability article (can’t find reference but will keep looking) that your brain subconsciously uses the ragged right edge to better gauge vertical reading position, allowing reader to more quickly travel through a paragraph. This matters less if you have good space between lines of text, but matters a lot if you’ve squished lines together to fit more on your poster (unfortunately, a very common scenario). Second, left-justified text has more predictable spaces within and between words, and that consistency makes sentences easier (faster) to read. Fully justified text can be especially awful when column widths are too small, and for smaller text boxes like figure and table legends. As an example of how awful those space problems can be, here’s an artificial dem on stration. These spacing issues are much bigger problems for people with dyslexia (20% of people, perhaps) and other reading disorders. That said, typesetting software such as InDesign have really good controls for minimizing the spacing problems of fully justified text. And some fonts (often the ones you have to actually purchase) are good at spacing themselves. Third, left-justified paragraphs suffer much less from the rivers and pigeonholes of white space that are sometimes created by full justification. These distracting visual elements are probably more of a problem for people or disciplines that are fond of big words, which coincidentally are those that love to have poster sessions. You can minimize rivers and pigeonholes by turning on automatic hyphenation, of course. In related news, Powerpoint doesn’t do auto-hyphenation, which makes it terrible for posters because you typically want to cram as much on a page as possible. Finally, errors in spaces between sentences (you just need one) are much easier to catch if you are using left justification.

But there are at least two reasons why you might reasonably ignore what I’ve written above. First, full justification looks so cool! If you want people to think you’re cool and professional, and you probably do, you might just go ahead and hit that button … because most viewers (and mentors, and poster judges) will also be similarly impressed. Unless they’re dyslexic, in which case they might hate you. A compounding problem is that justification looks cooler and cooler as you reduce font size … contributing to the word problem that plagues almost all conference posters. Second, there seems to be some research (again, I’m looking for citations I know I have somewhere) suggesting that full justification might increase a reader’s comprehension of the text. My guess is comprehension increases because one reads it more slowly. Changing the font every sentence might also increase comprehension in the same way, though I don’t recommend doing that. (Hyphenated paragraphs take longer to read, too.)

By the way, don’t center-justify text in figure legends and table captions. Many prestigious journals use centered text in this way, but I think they’d change to left justification if they could do so without admitting to prior foolishness.

As an aside, I recently purchased a Kobo eReader because I can specify left-justification. I couldn’t do that with my Kindle. I can also now read while floating in a pool (my Kobo is waterproof).

If for some reason the above didn’t bore you, please see more of the same at Designing conference posters. Drop me a note if you have actual data for any of the above speculation.

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Red milkweed beetles

Mating pairs of red milkweed beetles (Tetraopes tetrophthalmus) are not rare (they can couple for hours at a time), but I thought this couple looked cute, in a worried sort of way. The half-lidded expression is because their compound eyes are bisected by their antennae. Beautiful beetles.

Colin Purrington Photography: Insects &emdash; Red milkweed beetles (Tetraopes tetrophthalmus)

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Hummingbird and snowberry clearwing moths

Here are some photographs of the hummingbird clearwing moth (Hemaris thysbe) and the snowberry clearwing moth (H. diffinis).

Colin Purrington Photography: Insects &emdash; Hummingbird and snowberry clearwing moths

Day-active, colorful moths are rare enough, but these take it to the next level in their uncanny mimicry of hummingbirds and bumblebees, respectively. The mimicry presumably protects them from being eaten by predators such as crab spiders, praying mantids, and birds. In addition to the obvious behavioral and morphological resemblance to hummingbirds and bumblebees, the moths also make a slight humming noise that completes the disguise. The noise could easily be an unavoidable consequence of hovering flight (approximately 30 beats/second), but I wouldn’t be at all surprised if their wings are rigged in some way to exaggerate the noise. I’d love to know the answer to that. My other burning question is why the hummingbird clearwing moth has clear wings at all … I would expect selection to favor individuals that did not lose scales, because such a mutant would more resemble a hummingbird, which has opaque wings. I’m guessing that reason is not because fully-scaled wings are too heavy — the hummingbird hawk moth (Macroglossum stellatarum) in the Old World has opaque wings and can manage 70-90 beats/second (wow). I wonder whether a fully scaled wing might damp the humming sound. All photographs were taken at Natural Lands Trust’s Hildacy Farm Preserve in Media, Pennsylvania. Oh, and happy National Moth Week.

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) with unfurling proboscis

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) showing wing veination

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) nectaring

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) nectaring at wild bergamot

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) nectaring at wild bergamot

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) arriving at flower

Colin Purrington Photography: Insects &emdash; Hummingbird clearwing moth (Hemaris thysbe) nectaring at wild bergamot

Colin Purrington Photography: Insects &emdash; Snowberry clearwing moth (Hemaris diffinis)

Colin Purrington Photography: Insects &emdash; Snowberry clearwing moth (Hemaris diffinis)

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Sycamore tussock moth

Sycamore tussock moth (Halysidota harrisii) caterpillar at Hildacy Farm Preserve in Media, PA. I remember these as a child mainly because of their urticating hairs. But they are also really, really cute. I especially like the white ones because their orange tufts stand out better than on the yellow variety. Don’t you just want to pick it up?? If by chance you don’t know what “urticating” means, I highly recommend the experience. You won’t forget.

Colin Purrington Photography: Insects &emdash; Sycamore tussock moth caterpillar (Halysidota harrisii)

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Golden-backed snipe fly

This golden-backed snipe fly (Chrysopilus thoracicus) landed in one of my bird baths and drifted around for a few minutes on the surface tension. I’m not positive, but I think I’ve seen them do this in past years, too. I wonder whether they are looking for mosquito larvae, or perhaps adults. These flies have predaceous mouthparts, so they clearly hunt something. Sure wish somebody would PCR the gut contents of these things and let me know. Anyone ever seen them take something down?

Colin Purrington Photography: Insects &emdash; Golden-backed snipe fly (Chrysopilus thoracicus)

Here’s another one, albeit one with a damaged eye:

Colin Purrington Photography: Insects &emdash; Golden-backed snipe fly (Chrysopilus thoracicus) with dented eye

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