Differences distract from reading - True or not ?

[hrant]

> the time a word was displayed was increased or decreased

I would posit that the minimum duration a word needs
to be exposed to be read with near-total accuracy is roughly
proportional to some compound of its frequency and bouma
distinctiveness. Roughly, because foveal decoding is different
than parafoveal decoding, with the latter playing a very large
role in reading, at least according to the model I believe in.

hhp

[John Hudson]

Hrant: I actually believe that saccade-free reading is not only achievable, but also highly desirable.

Hmm. A saccade is a zero-input eye movement between fixations. The shorter the saccades and the longer the fixations, the slower the reading. The longer the saccades and the shorter the fixations the faster the reading. The upper limit of reading speed has always been comprehension: the longer the saccades and the shorter the fixations, the greater the chance of comprehension error and the more regressive saccades necessary to correct false readings. Even at these highest, most error prone speeds, though, the mechanism of reading remains the same: fixation and saccade. Not only do I not see grounds to consider 'saccade-free reading' achievable, I can't even imagine what it would be like. If you're getting rid of saccades, that implies you are also getting rid of fixations, since the two are part of a single mechanism. So what is left? What is the mechanism of 'saccade-free reading'? How does it work?

[Christopher Dean]

Perhaps I don’t understand the question, “What is the mechanism of 'saccade-free reading'? How does it work?”

You put on eye tracking equipment, look at a dot, present words in an RSVP fashion, and ask the subject questions about what they just read. Look at the eye-tracker data, their eyes haven’t moved, and presto, saccade-free reading. It’s just one long fixation. It’s clearly possible to attend to a single location without eye movements, I watch people in a lab do this all day. If their eyes move, the trial ends, and they try again. Are we on the same page?

Regarding “I would posit that the minimum duration a word needs to be exposed to be read with near-total accuracy is roughly proportional to some compound of its frequency and bouma distinctiveness.” It is my understanding that frequency and semantics play the primary roles in determining duration. Again, I’d have to do a little more digging to find references to support this, but I know there’s a lot out there on just that.

[Christopher Dean]

@Kevin: “Can anyone point to empirical evidence that making letters less individually recognizable ever results in improved word recognition?”

Not to my knowledge, but after a quick scan, I came across these two which I thought I’d throw out there for discussion (The second authour of the first paper caught my eye — pun intended).

————

Bouwhuis, D. & Bouma, H. (1977). Visual word recognition of three-letter words as derived from the recognition of the
constituent letters. Perception & Psychophysics, 25 (1), 12–22.

Abstract:
Word recognition is one of the basic processes involved in reading. In this connection, a model for word recognition is proposed consisting of a perceptual and a decision stage. It is supposed that, in the perceptual stage, the formation of possible words proceeds by separate identification of each of the letters of the stimulus word in their positions. Letter perception is taken to be conditional on position because of interaction effects from neighboring letters. These effects are dependent on both position in the word and retinal eccentricity, which are of particular relevance in reading. The letter-based approach rests on the strong relationship between the results from single-letter recognition in meaningless strings and in real words. Next, in the decision step, the many alternatives generated in the perceptual stage are matched with a vocabulary of real words. It is supposed that the final choice from among the remaining words is made in accordance with the constant ratio rule; frequency effects are not separately incorporated in the model. All predictions of the model are generated by means of data from earlier experiments. Despite being not optimally suited for this purpose, the predictions compare favorably with responses in word-recognition experiments.

————

Legge, G. E., Mansfield, J. S. & Chung, S. T. L. (2001). Psychophysics of reading XX. Linking letter recognition to reading speed in central and peripheral vision. Vision Research, 41, 725–743.

Abstract:
Our goal is to link spatial and temporal properties of letter recognition to reading speed for text viewed centrally or in peripheral vision. We propose that the size of the visual span — the number of letters recognizable in a glance — imposes a fundamental limit on reading speed, and that shrinkage of the visual span in peripheral vision accounts for slower peripheral reading. In Experiment 1, we estimated the size of the visual span in the lower visual field by measuring RSVP (rapid serial visual presentation) reading times as a function of word length. The size of the visual span decreased from at least 10 letters in central vision to 1.7 letters at 15° eccentricity, in good agreement with the corresponding reduction of reading speed measured by Chung and coworkers (Chung, S. T. L., Mansfield, J. S., & Legge, G. E. (1998). Psychophysics of reading. XVIII. The effect of print size on reading speed in normal peripheral vision. Vision Research, 38, 2949–2962). In Exp. 2, we measured letter recognition for trigrams (random strings of three letters) as a function of their position on horizontal lines passing through fixation (central vision) or displaced downward into the lower visual field (5, 10 and 20°). We also varied trigram presentation time. We used these data to construct visual-span profiles of letter accuracy versus letter position. These profiles were used as input to a parameter-free model whose output was RSVP reading speed. A version of this model containing a simple lexical-matching rule accounted for RSVP reading speed in central vision. Failure of this version of the model in peripheral vision indicated that people rely more on lexical inference to support peripheral reading. We conclude that spatiotemporal characteristics of the visual span limit RSVP reading speed in central vision, and that shrinkage of the visual span results in slower reading in peripheral vision.

————

I think a simple series of RSVP word recognition tasks using trigrams and different fonts for individual letters would be a step towards answering this question.

#ifyoureagradstudentijustgaveyouyourthesis

[hrant]

The main problems with RSVP:
- The parafovea is ignored.
- The pacing is artificial.

Just one of those would be enough to kill RSVP in terms of
providing true insight into immersive reading. With two the
second one can sit on the grave and make sure nobody lays
any flowers. But some people still have a shrine at home.

BTW, the reason boumas (assuming that's even being tested
as a data source) seem irrelevant in RSVP is because in the
fovea you don't need boumas: the individual letters are clear
enough to unambiguously compose the word.

hhp

[Denis_Masharov]

I understand so - that the important thing is not to cross the line between "recognizability" and "personality" of the letter.

[William Berkson]

John, I was trying to argue that there is not a linear relationship between the legibility of individual letters, summed, and the recognition of those letters in a word, even if they are well spaced. I don't know if it's true, but I can imagine that ornate, highly differentiated letters might be easier to distinguish, but do worse in word tests. By letter legibility I mean that the letters could be recognized in very short, millisecond times, without many errors. And the same for "word legibility": recognition in short time periods, reliably. I don't understand Hrant's theory, but on Peter's that might be possible.

[dezcom]

Has there ever been any research or even discussion on what is "readable enough for a given task". One end of a continuum might be a phone book number and another might be "War and Peace". We could place things like brochures, ads, posters, etc.., wherever they may fall.
My point in this is that I assume there are points where the optimum for one task differs from another. There is a place where the form of the typeface may aid communication of the message of the text yet reduce continual reading. There may be a place where the form of the text has so little communication of content (beyond just as a letterform) as to be a non-factor.
When designing a typeface for a given target use, it might be valuable to know where these breaks occur.

[hrant]

> If you stare at one point fixedly enough to suppress saccades,
> within seconds your visual field will narrow to a small point.

I'm assuming that doesn't happen when the view
is changing, otherwise RSVP couldn't even exist.

> healthy reading of extended texts (i.e. where the
> reader is not moving his lips) is mostly saccade-free

?

--

If there could be a good way for a reader to trigger the refreshing of
the display* then we should be able to read [even more] immersively
by not having to saccade (even if my technique of enlarging** text in
proportion to parafoveal depth isn't implemented).

* And a way to trigger a regression...

** And probably also loosening.

hhp

[quadibloc]

@hrant:
I actually believe that saccade-free reading is not only
achievable, but also highly desirable.

This comment might be more controversial than it deserves to be, on the basis of the fact that saccade-free seeing is not possible. If you stare at one point fixedly enough to suppress saccades, within seconds your visual field will narrow to a small point.

However, while eye movement is an essential component of vision, and hence of reading, and, on top of that, the saccade is typically a largely involuntary motion... you're still not nearly as wrong as all this makes you sound.

Because, of course, when reading, one doesn't stare at a single word, with one's eyes wandering back and forth along that word, the way one watches a movie or TV screen, or even admires a painting or sculpture.

One's gaze is in constant motion, but even with occasional saccades, in general, over the majority of words, one's gaze will pass unidirectionally, if one is reading at a good speed. Only if one is reading very slowly will a saccade be likely to take place during the reading of the majority of the words, or, say, even the majority of the words longer than three letters.

Thus, despite the universality of the saccade, the time scale of that phenomenon needs to be kept in mind. Normal, healthy reading of extended texts (i.e. where the reader is not moving his lips) is mostly saccade-free, and proper typography will facilitate that.

@Christopher Dean:
You put on eye tracking equipment, look at a dot, present words in an RSVP fashion, and ask the subject questions about what they just read. Look at the eye-tracker data, their eyes haven’t moved, and presto, saccade-free reading. It’s just one long fixation.

Possibly I misunderstood Hrant's comment, if in order to engage in the saccade-free reading of a book, it is necessary to somehow have its pages presented to me as one word at a time flashed on a screen.

But in checking, I see I misunderstood the word "saccade", and was mistakenly restricting it to involuntary movements of which we are generally not consciously aware which allow us to look at a wider visual field than our fovea can handle.

Those shouldn't normally be part of reading, but the voluntary movement of the eye from one word or part of a word to the next also counts as a saccade - and, indeed, some words are long enough not to be contained in the fovea if presented in a legible size.

One could still see the whole shape of a word and recognize it without having applied acute foveal vision to every letter of the word, but I think it would take a dedicated speed-reading enthusiast to be able to employ such a technique to advantage.

[quadibloc]

While you (Hrant) were replying to my post, I was editing it to reply to Christopher Dean's post as well as yours. Hopefully, things are clarified a bit.

[John Hudson]

Christopher, I wasn't talking about RSVP -- and I don't think Hrant was either. Based on previous discussions going back several years, I understand Hrant to believe it is possible to massively increase typical reading speeds, not involving presenting text in new ways à la RSVP. So I'm interested to know how Hrant sees 'saccade-free reading' working.

[Personally, I consider RSVP a kind of parlour game, sort of interesting in that it shows that our word recognition skills are immediately adaptable to 'reading' text presented in novel ways. But it doesn't seem to me very relevant to how we actually encounter text, to how we are likely to continue to encounter text, or to understanding a reading mechanism broken down into saccades and fixations.]

[hrant]

Uh, if we agree that "massive" is like 20%, OK. :-)
That's if we start making fonts like we're supposed
to, as opposed to how we've been making them.

To go beyond that I believe we do in fact need
to move to the "active display" of text, instead
of forcing the reader to keep moving his field
of vision, not to mention his neck, hands, etc.

hhp

[John Hudson]

Aside:

If you stare at one point fixedly enough to suppress saccades, within seconds your visual field will narrow to a small point.

Which can produce some very cool optical effects. I was staring at the Blessed Sacrament exposed at a href="http://farm6.static.flickr.com/5257/5461485268_403245c316.jpg">Brompton Oratory, and suddenly a massive baroque church all became disconcertingly parafoveal.

[John Hudson]

Bill, I don't think there is a strictly linear relationship between letter recognition and word recognition, but I do think they are mutually supporting, not in opposition, and improve or degrade more or less in parallel. Linguistic context gives word recognition an advantage that enables some letters to be more easily recognised in words than in isolation, but I don't see any basis to assume that such letters result in better word recognition than more individually legible ones would.

I do think, however, that individual letter recognisability probably gives diminishing returns to word recognition, which is why reading speeds seem only marginally affected across a significant range of typeface designs and styles. In other words, endlessly refining individual letter recognisability will obtain smaller and smaller gains in reading speed and accuracy. But the point is that they do seem to continue to move in the same direction, albeit at increasingly disproportionate rates. There doesn't seem to be a point at which improving individual letter recognisability degrades word recognisability.

[hrant]

OK, let me try an actual image (although I feel that the
imaginative requirement of textual communication is
generally more fruiful)...

Taking the invented phrase from my (admittedly
extremely over-simple) "How We Read" page*:

* http://www.themicrofoundry.com/ss_read1.html

Imagine this is what an "active text display" (which I
now dub AcTeD :-) would show when the fixation is at
"wasn't". In addition though I would probably change
the serif-ness of the text, from none at the fovea to full
serifs in the parafovea. (But I'm not yet sure the "He"
there makes sense).

hhp

[John Hudson]

Hrant: Uh, if we agree that "massive" is like 20%, OK.

In Thessaloniki you were claiming c. 700 words per minute. No?

Average adult reading speed in English is 250 words per minute. More significant to my mind is that average comprehension at that rate is only 70%. Comprehension demonstrably drops as reading speed increased, with tested 'speed readers' averaging a mere 50% in comprehension.

Now, I'm of the perhaps idiosyncratic opinion that the purpose of reading is to understand, so I'm only interested in increases in reading speed that do not reduce comprehension, and most of the time wish that people would take the time to read more slowly.

[John Hudson]

Hrant, that's an interesting image. One thing I wonder is how the brain would cue the next fixation if the text setting is changing so completely during the saccade and, of course, how would the AcTeD system know where that next fixation would be until it happened, which is too late to change the display?

[hrant]

Well, I actually believe experienced readers (the best and only real
benchmark) can do over 400 wpm now, with existing typography.
Those much lower numbers are from flawed (far too fovea-centric)
experiments. But maybe 700 was sensationalist, sorry. Although I
do think that an AcTeD system could exceed that.

BTW, I do wish Kevin would point to the experiment that
he said shows improved reading with tighter spacing.

> I'm only interested in increases in reading
> speed that do not reduce comprehension

Me too.

--

Good questions (including some I already
wondered about above). Let's figure them out.

hhp

[William Berkson]

>the experiment that he said shows improved reading with tighter spacing.

Kevin may (or may not) be alluding to this paper, which found that the word superiority effect disappears with very widely spaced letters. I predicted that this should happen on Peter Enneson's theory. Peter then did a literature search and found this paper, which had already demonstrated this. Kevin was kind enough to repeat some of the experiments, with variations, but his conditions didn't have the same precision as the early ones, done with a tachistoscope and printed matter, rather than on a computer, whose screen refresh is on the order of the times involved in flashing the words. And the results were not very clear. Peter's view is that to get more informative results we need a good control on what is called the SOA (stimulus onset asynchrony). But it's probably too much to try to get into this here.

[quadibloc]

Since one thing has emerged from this discussion:

letter recognition bad
word recognition good

it has occurred to me how this new insight can be translated into a weird new typeface designed to supercharge the readability of text!

Since descenders and ascenders play such an important role in determining the shape of a word, have them become gradually bolder as they extend away from the x-height region of the letter.

Of course, the difference between, say, a, v, and r individually, and c, e, and o on the other hand, also affects word shape, so something might be done to exaggerate the general shape characteristics of small letters.

[William Berkson]

>Since descenders and ascenders play such an important role in determining the shape of a word, have them become gradually bolder as they extend away from the x-height region of the letter.

They're called serifs :) And with old styles there is often swelling toward the serifs...

[Kevin Larson]

I haven’t quickly found a reference showing that letters are more accurately recognized in time and distance threshold tasks with more space between them. I suspect that Bouwhuis & Bouma first showed this and that Pelli has shown this in his crowding studies. I am confident that Sheedy’s lab has done this with a distance threshold task, but I haven’t found a publication of this finding, and I have replicated this in a unpublished time threshold study. I’ll be talking about that study at the upcoming Digital Reading conference.

Rayner’s lab has published some of the findings showing that reading speed is faster with Consolas and Georgia when letter space is decreased and word space is increased.

Rayner, K., Slattery, T.J., Bélanger, N. (2010). Eye movements, the perceptual span, and reading speed. Psychonomic Bulletin & Review, 17 (6), 834-839.

Abstract:
The perceptual span or region of effective vision during eye fixations in reading was examined as a function of reading speed (fast readers were compared with slow readers), font characteristics (fixed width vs. proportional width), and intraword spacing (normal or reduced). The main findings were that fast readers (reading at about 330 wpm) had a larger perceptual span than did slow readers (reading about 200 wpm) and that the span was not affected by whether or not the text was fixed width or proportional width. In addition, there were interesting font and intraword spacing effects that have important implications for the optimal use of space in a line of text.

[Kevin Larson]

Again, I agree with John that I believe that word recognition will generally follow letter recognition. Easy to recognize letters will lead to easy to recognize words.

But in the interest adding meat to those that disagree, Arnold Wilkins has an interesting line of research where he demonstrates that fonts with very high periodicity (e.g. the picket fence) lead to slower reading speeds. He has also demonstrated that modifying the letter shapes to reduce the picket fence effect increases reading speed. He didn’t look at letter recognition for his modified letter forms, but I assume that would perform poorer on a letter recognition test.

Wilkins, A., et.al. (2007). Stripes within words affect reading. Perception, 36, 1788-1803.
http://www.essex.ac.uk/psychology/overlays/2007-177.pdf

[quadibloc]

@William Berkson:
And with old styles there is often swelling toward the serifs...

Yes, but I'm thinking of something on the order of the recent attempt at a typeface designed to mitigate dyslexia. Here is the illustration I was drawing to modify my earlier reply: