Mac Forum / Country Specific / Australian Mac Group / September 2007

I've often wondered why it seems more difficult to read text on a screen than
on paper. There are some obvious reasons. For example, until recently, screens
were CRTs, which was like looking at a light bulb. No wonder our eyes got
tired. LCDs are a bit better in this respect.

But I suspect the real reasons are more subtle, and associated with the way we
read. The printing industry has hundreds of years of experience that
contributes to the way the printed word appears. Some interesting points are:

1. People think that we read by looking at the letters. In fact, we read by
looking at the overall shape of a word and recognising that shape. You have
probably noticed that all upper case text requires more effort to read than
lower case. This is because lower case text has more variation in the shape of
the word. Upper case is usually just a rectangle, whereas lower case has
ascenders and descenders on letters that make its shape more distinctive.

2. Words are defined by the spaces between letters. The gap allows us to
automatically recognise that there is a new word, and begin to recognise the
shape of the new word. Now sometimes fonts leave quite large spaces between
the letters of a word. The fixed pitch fonts are a classic example. If it is
not easy to distinguish the beginning of a word, our eyes have to hunt around
to find each new word. Serif fonts are helpful in this respect, as they tend
to join adjacent letters together and help to make the shape of the word.
Sans-serif fonts, OTOH, can leave small gaps between letters of a word which
make the eye work a bit harder to distinguish the beginning of the next word.

3. If you look at a newspaper, you will see that it is made up of a lot of
fairly narrow columns. Newspaper publishers, you would think, would want to
get as many words as possible on a page, and all these columns waste space
where they are right justified inside each column. Why not just have one long
line across the whole page? The reason is that when reading, the eye gets to
the end of a line, then tracks back to the beginning of the next line. If the
line is too long, the eye often makes a mistake tracking back, and will go
back to the start of the same line, or to lines further down the page. It
turns out that the eye is happiest with lines that are about 10-12 words long.

All of these things are subtle, even minor issues. But they contribute to the
work they eye has to do to perform the act of reading. Over a few paragraphs,
the extra effort is probably negligible. If you are reading a book, however,
these factors become very significant. That's why you rarely see books in all
upper case, using sans-serif fonts, or with very wide pages. (There are
exceptions, of course, where publishers are trying for an effect. For example,
sans-serif fonts tend to look more modern which might be something the
publisher wants to achieve, even at the expense of ease of reading. Magazines
often use sans-serif fonts since the articles are rarely long enough to cause
eye strain.)
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Now that background is intended to demonstrate that there are subtle forces at
work. In considering my own experience reading on a screen and on paper, I
have a few observations about the difference between paper and screen.

Firstly, even though screens are getting better, they rarely have the density
of printed text. A resolution of 100 dots per inch does not compare with the
2400+ dots per inch of a typesetter and printing press. This allows more
definition to the shape of the letters, although as stated above, the shape of
the letters is not really important. What might be important is the spacing
between the letters, and particularly the space between the lines. (Points 2
and 3 above.)

Secondly, there is the physical structure of the text being read. A book is
made up of a number of distinct units called pages. You can look at it and say
"I have read a third of the book" or "That interesting bit was about half way"
or "I remember reading that at the bottom of a right-hand page". You can stick
your finger or several fingers in between the pages and flip back a few pages
to check something. You can even dog-ear a page or write on it.

On a screen, the text is continuous. There is nothing to indicate how much you
have read (other than the scroll bar, but this requires conscious action to
note where it is). Memory of where in a document something was is more
difficult to achieve. There is no way (at present) to provide those temporary
or permanent markers.

Thirdly, at present screens are not shaped in a natural reading way. For the
line length reasons above, books tend to be printed in portrait mode. This
gives a reasonable length of text to read and absorb without interruption to
the reading process. Screens, however, are usually in landscape mode. With
reasonable sized text, you only get about half a page before you have to drag
the scroll bar or hit the next page button. Maybe it is just many years of
training, but flipping over a page is something that requires no
concentration. Finding the mouse or the next page key and clicking requires
enough effort to be a distraction from what you are reading.

I'd be interested to know how other people feel about these thoughts...

Cheers

David

[Responding to older postings after a break!]

If you hadn't mentioned it, I wouldn't have noticed. (That's a worry!)

I think you could make a reasonable argument that way - the
business-everything else divide was very powerful then.

If they could have made it possible for individuals to buy at a
reasonable price and not just institutions that could afford the higher
one, it would have worked.

When was that?

it was the Mac Pluses that were well priced - and Jobs hasn't made the
same mistake again with this - the first iMac line was brilliant for the
time, sexy (then!) and affordable.

Rifty