Hi.
I'm Dave Goldberg with the Computer Science Laboratory
at the Xerox Palo Alto Research Center,
and I'm here to tell you about some thinking we've been doing
about pen-based computers--
so computers that use a pen instead of a keyboard.
And in particular, we're interested in the problem
of how you get text into such a computer
if you don't have a keyboard.
Now, the more I work with pen-based computers
or styluses, the more impressed I
am about the invention of the keyboard.
And one of the great things about the keyboard
is it works well for beginners and experts.
A beginner can enter text just by picking out
one letter after another.
And it's slow, but it works.
With practice, you actually get pretty fast at it.
And if you want to go even faster still,
you can learn touch typing.
It takes a little while to learn touch typing,
but touch typing is really fast.
And not only is it faster, but you have eyes-free operation.
You don't have to look at your hands while you're typing.
Well, let's see what happens with a stylus
and how people write with a stylus.
I have here an NCR 3125, a pen-based computer.
It's running PenPoint.
And the way this system works is that you get a grid of boxes.
You write one letter per box.
Print your message.
And then when you're done printing,
you hit the OK button.
It tries to recognize your writing.
If there are any errors, you just write over it correct.
Try to get that I there.
Change that to an M. And then when
you're happy with your message, you hit the OK button.
And it's inserted into your text.
Now, this is fine if you're just entering a little bit of text.
But it gets pretty tedious if you're entering a whole memo.
So imagine you're at a dull meeting,
and all you have is your pen-based computer.
And you want to make use of the time by writing some documents.
This is going to be pretty tedious,
and you're going to wish you knew something
like touch typing.
So that's what we've been thinking about
is what's a system that you can learn
that will make text entry with a stylus easier.
Now, you'd like the system to be better than printing.
And what does "better" mean?
It means faster, of course, but there's more than that.
We want it to be more flexible.
And computers come in all sizes.
Here, we have a little experimental pen computer
with a tiny screen.
You'd like the system to work very well on a small screen.
And you'd also like to be more accurate
than ordinary printing.
The problem with ordinary printing
is that it's a very ambiguous process.
Let me show you an example.
Let's take the letters R and V. An R looks like that and a V
like that.
They're different if written carefully.
But in real life, people tend to do that--
can't really tell if that's an R or a V.
And there are many examples of letters
which blur together like that.
So we'd like a system which is more accurate,
as well as being faster and more flexible.
So what I'd like to do next is tell you
about our idea of a system that plays the same role as touch
typing for keyboards does, but this is for pens instead.
Well, our idea is to use a special constrained version
of the alphabet, which is easy to learn--
takes about 10 minutes to learn--
but works much better with a stylus
than the ordinary alphabet.
And here's our alphabet.
There are five different shapes, and each of them
come in four different orientations.
And unlike the ordinary alphabet,
each shape is quite different from the next.
So as you write more quickly, you
don't get the shapes confused.
They don't blur into one another.
Well, let me show you how easy this is to learn.
Many letters are the same.
For example, a V is just a V. An S is just an S.
And other letters are kind of the obvious subset.
So for example, an F, that consists of two parts.
And in our alphabet, we just take
the one half of the F, kind of a natural subset.
Other letters are the same.
For example, a T--
normally, that's two parts.
We just take the crossbar of the T.
This, again, is just an easy-to-remember subset.
Now, you notice that each of these letters
is a single stroke.
So we call our alphabet "unistrokes."
And the reason why this is useful
is because when you're writing on a teeny little tab,
it's very convenient to write one letter on top of the next.
Not only does this save space, but you don't
have to look at your hand.
It's like touch typing that it's eyes-free.
So you can be taking notes or maintaining eye contact
while you write with your pen.
The reason why this ties in with single strokes
is that with the ordinary alphabet,
many letters are multiple strokes.
For example, capital T, capital H--
there are five strokes all together,
even though there are only two letters.
And so if you wrote one on top of the next,
the computer is going to see five separate strokes
and has to figure out, oh, the first two of those group
together to a T. And the next three,
that groups together to an H.
And that's-- it can try to figure that out,
but that's going to be a cause for errors and make the system
less accurate.
With our alphabet, every letter's a single stroke.
It's completely unambiguous where
one letter starts and the other letter
ends, because each letter is a single pen up, pen down.
Well, another advantage of our system
is that it's much less ambiguous than ordinary writing.
What do we do about things like U and V?
That's a pair which is easily confused in ordinary writing.
And what we do in our system is we use stroke order
to distinguish those.
So a U in our alphabet, what we do is it's the same shape.
It's easy to remember.
It's an ordinary U shape.
But whereas a V, you write that in the ordinary direction, a U,
you write that in the opposite direction.
So it's easy to remember.
The shapes are the same as the ordinary shapes.
But to the stylus--
to the computer reading the stylus,
they look completely different because the pen is
traveling in a different order.
And so that solves the ambiguity problem
in a way that's easy to remember.
A final example-- advantage of unistrokes
is that they're faster to write than ordinary letters
because the common letters are all straight lines.
So whereas a T in the ordinary Roman alphabet
is two strokes, in ours, it's just a single straight line.
And we've mapped all the common letters
to straight lines, which makes it easier to write quickly.
Well, enough of this theory-- now,
let me show you the system in action.
Here's the program we use for testing our system.
It's a mail sending program.
Users send real mail messages using this.
There are no modes.
You just write letters in this writing area,
and they appear on the top.
To enter a subject line, I tap on the word Subject.
And I can enter my subject line.
And then for a message, I tap on Message.
Now, you'll notice by default, every letter is lowercase.
To make an uppercase letter, I hold down this side button.
So I can erase the lowercase i.
Press the side button--
makes an uppercase I.
And I can insert at any point.
So if I draw a caret at the end, that moves the insertion point.
And now, if I want to, say, put an exclamation point
at the end, for those rare letters that you can't remember
the symbol for, we've got little reminders here with buttons.
So I tap on the exclamation point button,
and it inserts my exclamation point
at the end of the sentence.
A stylus is useful because it scales from the very small,
like this teeny tab, to the very large, like this live board.
Now, the problem with a live board
is that although it has a keyboard, the keyboard's
way over there.
And if I'm standing over here, it's
not very convenient to use the keyboard.
And that's where a stylus comes in.
I'm always holding the stylus in my hand,
and so it's much easier to enter text with the stylus
than to walk over to the keyboard.
Well, to summarize, the problem with a stylus
is that entering text is not as easy as it is with a keyboard.
So the stylus is good because it scales.
It's not so good when it comes to text.
And that suggests that if a stylus is
going to be a truly useful input device,
we need to discover some analog of touch typing, a system that
can be learned.
But once you learn it, entering text is a whiz.
And although we don't know what that system is,
it seems that unistrokes may be the solution
to the problem of finding a good analog of touch
typing for a stylus.