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Palm OS Programming, 2nd Edition by Neil Rhodes, Julie McKeehan

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Works Great and Is Simple to Use

Now, we are into very subjective stuff and we are the first to admit it. When we say a handheld has to “work great and be simple to use” many of you may justifiably want a much more exact description of what this means—how the various combinations of features that go into the creation of a particular handheld translate into a great user experience. We would be the first to admit that how you compare and measure things like great backlit color screens against long battery life is notoriously open to debate. Whether the presence of a cool MP3 player or the ability to look at web pages is more important than the price is debatable.

It would be great to see about five years into the future when it will be obvious which were the right choices for today’s customers. We could all pontificate about how we knew all along that this set of features and device options were the golden ones. Barring the presence of a rift in the time-space continuum, however, we are forced to guess. So, we will tell you about our guesses and Palm’s guesses. We will tell you what Palm thinks “works great and is simple to use” means. These guesses have led to design decisions in the Palm OS and on Palm OS devices that will determine how you develop for this platform. Stated most generally, what Palm means when it says “works great and is simple to use” is that usability matters more than looks, and simple common features that work well are more important than lots of built-in choices. Quintessential handheld tasks better be easy to do and faster than lightning.

Let’s see how these general ideas translate into current day device and OS decisions. First, let’s examine the battery life issue, which we file under the category of “usability matters more than looks.”

Battery Life

Palm OS devices, whether built by Palm or by its licensees, last a long time between battery changes or recharging. This is a big deal at Palm. Look, for example, at Palm’s color m505 (a new device as of May 2001). Reviewers have said its screen isn’t as clear as those of Pocket PC color devices. But the m505 has a much longer battery life than the color Pocket PC devices. This is an important difference and one you should not gloss over—it will dramatically affect how people use each device.

People use a computer differently if they expect it to last weeks instead of days. Palm is betting this is a crucial difference, and we agree. Most people can take their Palm unit on a trip (whether on business for a week or rock climbing for 10 days) without worrying about the charging mechanism or extra batteries.

With an 8-12 hour rated life, a Pocket PC owner will learn to carry spare batteries or power cables (much like a notebook computer user). These differences in battery life are across-the-board differences between Palm units and Pocket PCs as you can see from Table 1-5, which shows some comparisons of screen color, processor speed, and battery life.

It should be obvious from Palm’s devices that long battery life is an important part of a great user experience. As you can see, it is more important than many other features. It’s more important than having the best color screen and more important than having a backlit screen with which you can navigate a pitch black cave. To be a great handheld, a device has to run for a long time. There is more to it than this, however. To be a great handheld, a device has to perform certain quintessential “handheld” tasks very simply and faster than lightning.

Table 1-5. Pocket PC and Palm OS device battery life and specifications

Device type

Manufacturer’s claimed battery life

Battery type

Display type

Backlit display

Processor speed

Pocket PC

Casio Cassiopeia E-125

8 hours

Lithium ion

Color

Yes

150 MHz

Compaq iPAQ H3650

12 hours

Lithium polymer

Color

Yes

206 MHz

Compaq iPAQ H3150

14 hours

Lithium polymer

Grayscale

Yes

206 MHz

HP Jornada 525

8 hours

Lithium ion

Color

Yes

133 MHz

HP Jornada 545

8 hours

Lithium ion

Color

Yes

133 MHz

HP Jornada 548

8 hours

Lithium ion

Color

Yes

133 MHz

Palm OS

Palm IIIc

14 days

Lithium ion

Color

Yes

20 MHz

Palm m505

21 days

Lithium polymer

Color

No

33 MHz

Palm m500

21 days

Lithium polymer

Grayscale

Yes

33 MHz

Handspring Visor Prism

14 days

Lithium ion

Color

Yes

33 MHz

Handspring Visor Edge

28 days

Lithium ion

Grayscale

Yes

33 MHz

Sony CLIE PEG-N710C

15 days

Lithium polymer

Color

No

33 MHz

When you further compare them with the Palm units that run on standard AAA batteries instead of rechargeable ones, the differences become even greater (see Table 1-6).

Table 1-6. Palm OS devices with alkaline batteries

Device type

Rated battery life

Battery type

Display type

Backlit display

Processor speed

Palm VIIx

2-4 weeks

2 AAA

Grayscale

Yes

20 MHz

Palm m100, 105

4.3 weeks

2 AAA

Grayscale

Yes

16 MHz

Handspring Visor

6-8 weeks

2 AAA

Grayscale

Yes

16 MHz

HandEra 330

4-8 weeks

4 AAA

Grayscale

Yes

33 MHz

Common Handheld Tasks Are Simple and Fast

Let’s start by explaining that a quintessential handheld task is one that a handheld user is going to do all the time.

A perfect example is setting an appointment. Imagine I have to set an appointment for one week from tomorrow. I am on the phone right now with the dentist and the receptionist is telling me to bring my kid in at 2 P.M. a week from tomorrow. That task had better be easy to do and fast. To accomplish this on my Palm m505 takes about 10-15 seconds (taking the device from my pocket, turning the unit on with the button push that opens the Date Book, making three quick taps, and inputting the appointment text Nick’s dentist appt. in the correct appointment timeslot).

Here is another example. I want to call someone and I need her phone number. Looking that up is also quite easy; it only takes a few seconds. To accomplish this, I switch on my Palm handheld and open to Address with the press of one button. Then, I write the first letter of her last name. At that point, most likely, the name will be on-screen along with the phone number. (I can keep writing letters to narrow the choices.)

Both of these are quintessential handheld tasks. The way the handheld is designed, the buttons it has, and the application it uses all revolve around this idea of optimizing the user’s experience with common tasks. This idea has enormous implications for you as a software designer.

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