About 8 years ago life was simple: we all started with big laptops and small simple mobile digital assistants. Since then the laptop has become more portable and the PocketPC has become more all-round and powerful. But life has become even more complicated because the mobile market has become more and more crowded: we now have Windows Mobile powered smartphones, PocketPC phone editions, UMPC's (Ultra Mobile PC), TabletPC's and laptops. All these platforms are converging towards a specific form factor: TabletPC, UMPC and PocketPC are starting to look alike. But where does it lead us? What does it bring us in real life?

Some people really argue that these form factors in the mobile market are competing for the same user, while others see them as supplements to each other. To make matters even more complex, PocketPC's are getting keyboards and VGA screens, approaching their capabilities and really giving laptops a run for their money. Some even make their PocketPC completely behave like a laptop. The executives of Symbian even say that the laptop will be completely replaced by the smartphone, while in practice we actually do see people switching back from PocketPC to TabletPC. When comparing the HTC Universal with a smaller TabletPC, the difference is in fact quite small. This raises the question: how feasible is it to just use the PocketPC as a laptop?

For many of the mobile professionals, the goal of the exercise is reducing the weight carried around while remaining flexible. With an average weight of 4 Kg (9 lbs) for a laptop and many papers to carry, many people have the ambition to reduce the weight of the stuff they carry. While everybody has this ambition to reduce the weight, many people look to integrate as many devices into one device (preferably weighing much less than the items combined). We saw this with the integration of the mobile phone and PDA, and now a lot of people are wondering if they cannot replace the laptop with a powerful, much smaller and lighter, device to reduce weight even more. Especially since PDA's are becoming more powerful and keyboard equipped.

The trend

Mobile devices have been becoming more powerful every year. Looking at the current state of affairs, currently sold Windows mobile devices have as much power as a laptop 6 years back. Current mobile devices are getting VGA screens and keyboards, making them resemble laptops even more. With the introduction of internet connected devices the gap in terms of connectivity with laptops are closed even further. Some people even state that all types of mobile devices will be replaced by one big device, where others say this already happened and declaring the mobile phone as the winner.

In fact, there is a continuum of mobile devices, each having specific capabilities. PDA's were traditionally seen as desktop extensions, a simple way to take data from a desktop into the field where desktops or laptops might get in the way or get hurt. However, with the introduction with devices like the OQO there are also laptops with a PocketPC formfactor, but with PC capabilities. These are some exotic exceptions, but in the general product categories, supported by Microsoft, another shift is taking place: the mobile space is getting crowded. We always had the laptop, but a lot of additions have been made in the space between the Laptop and the smartphone. First there was the TabletPC. The TabletPC has come to an accepted standard screensize of about 12" and a weight of about 2 kg (about 5 Lbs). But this was not the latest addition. The introduction of the Ultra Mobile PC (UMPC in short, but also known as Microsoft's Origami) followed: with a screensize of about 7" somewhere between the TabletPC and bigger PocketPC's.

However, with PocketPC's becoming more powerful every day, they could very well be considered small laptops, replacing UMPC's, TabletPC's and even laptops. But are they up to the task and capable replacing these devices, or is it just a mobile utopia to have a small device that is capable of replacing all other devices?

Pro's and con's of mobile devices

The sales volumes of PocketPC's have been tremendous, so they must be useful for something. There are certain advantages of PocketPC's which make them more appropriate for mobile users above laptops. Advantages that make some people consider choosing the PocketPC over the laptop. But others really object to the idea of PocketPC's replacing laptops. But besides subjective feelings, there are some real arguments there.

Pro's of mobile devices

Generally speaking, PocketPC's have a better battery life than laptops, even when the one considers the smaller batteries used on PocketPC's. This is partially due to a PocketPC using less CPU power to run more basic applications and being more efficient with resources. A big factor is the screen, which is one of the biggest users of energy in both devices. With PocketPC's having screens to 4" and laptops starting from 11", a PocketPC screen is a lot more energy efficient than a laptop screen. Besides having smaller screens and more efficient hardware, PocketPC's also lack moving parts (like harddisks and floppydrives) that consume lots of energy. Therefore it is no wonder that a PocketPC has about 4 to 6 hours of battery life when used continuously, while an average laptop just makes 2 to 3 hours on a battery.

Although there are specific exceptions, especially the MIL-specification designed laptops, PDA's are generally better conditioned for the use outside an office environment than laptops are. Laptops and TabletPCs have big reflective screens that do not react well to sunlight, were PocketPC screens are translective and stil remain readable in direct sunlight. But also the physical size and design of laptops makes them more vulnerable with respect to physical damage, dust, moisture and rain.

Another benefit of PocketPC's is that they are much easier to carry around than a laptop. When you have to carry a laptop from and to meetings, running through airports, walk to trains, etc. the weight and physical volume is becoming a problem. PDA's are much smaller and lighter, making them easier and comfortable to carry them along, also greatly increasing the availability of the device for the user. Besides being much easier to carry along, PocketPC's also have much shorter boot times: you turn the device on and its ready and willing to serve you. A laptop has to come out of hibernation, taking at least 1½ minute, which is a long time when you quickly want to check your mail or make an appointment in a hurry. So basically, it is a choice between a device that is requires a huge bag to transport and reacts slowly on the one hand and something that can easily be transported wherever you go and is directly there when you need it on the other. Most people do prefer the later simply out of practicality and comfort.

Another effect of of the limited physical size of PDA'a is that, even with external keyboards attached, they can be used in the most idiotic small places. They are better equipped to be used in small compartments, like train cabins and airline seats. A PocketPC can be used in the most crowded train compartments, while a laptop can be embarrassing in an empty train. This makes them more usable than laptops/TabletPC's in specific situations.  For people being regularly in such environments a PocketPC might be the most optimal solution.

Downsides of continuous use of mobile devices

Although PDAs certainly have their practical advantages, there is a downside to using PDA's as a laptop replacement. There are some severe ergonomic downsides to using mobile devices continuously, both in medical as in productivity perspective. As some people indicate, PocketPC's are better used for accessing data than for generating data, although the casual gathering of small parts of data it could be quite successful.

The effectiveness of the keyboard in continuous use as a laptop replacement can be questioned. According to research, reducing the keyboard size severely reduces the effectiveness of the keyboard. The integrated keyboards are quite small, so basically a short e-mail might take much longer to make, even if it is made in time that was otherwise wasted. A bigger e-mail might take about 30 minutes to compose, instead of the 10 minutes it would require on a laptop. But that is not the only concern. Using such a small keyboard isn't just ineffective; it might even be dangerous for your health. Although the seriousness is still under discussion, there are cases known of people getting RSI on their thumbs from the small keyboard. Some companies see it as a threat to their employees, while others (especially physical therapy companies) see it as a business opportunity. So using a keyboard as an input method for longer periods of time might not be the smartest thing to do.

Other input options, like using handwriting recognition, are less straining on the concentration and reducing the physical strain on the user. In fact it could be the best way to interact with a PocketPC in a setting where not much attention can be given to the device. However, after extensive training the handwriting recognition ratio is around 95%, which sounds great but in practice means that 1 in 20 words need some correction before it can be sent to someone else. In practice, a keyboard might be a lot less of a hassle than handwriting recognition. So a PocketPC might lack an effective way of data entry.

Even for reading large portions of data, a PocketPC might not be your technology of choice. Screen size greatly determines the information processing capabilities of an user and small screens are not suitable for reading large texts or complex operations. According to research fnded by apple, a bigger screen might double your productivity. So that huge spreadsheet or 80 pages of text might become a disaster when it ends on your mobile device. And again it is not just a question of effectiveness, there are health issues concerning the prolonged use of small screens for reading text: there are cases known of eye strain because of the small screen. So even for reading documents, a PocketPC might not be able to replace the laptop.

Besides this, the overall positioning of the screen might prove to be vital as well. Where laptop, TabletPC and UMPC have the option to add an external keyboard and monitor, the PocketPC lacks that kind of capabilities. As safe computing guidelines advice, there has to be some distance between screen and keyboard as well as a good viewing angle for the screen. Both the distance and viewing angle are impossible to create with a PocketPC, making it impossible to use it for a prolonged time in an ergonomic acceptable way.

Real life experiments 

Sometimes a hardened user experiments (voluntarily or forced by failing equipment) with the possibility of just using its mobile device. Kevin C. Tofel experimented with a UMPC as a laptop replacement and quickly discovered that it was a workable solution with some restrictions. But an UMPC is a bigger than a PocketPC and following the above research, it might make a big difference. But there have been some real life experiments conducted with PocketPC's.

The best documented and thorough experiment is from Don Sorcinelli who replaced his desktop with a PocketPC for 5 complete days. He did not stop at the easy parts of webbrowsing and reading small e-mails. He focused on his role as an "information worker" and used his PocketPC for all his tasks. The PocketPC used was augmented with a lot of extra applications, to compensate for shortcomings in the OS. Although he could perform most tasks (like writing documents using Textmaker, creating powerpoint presentations etc.) he does mention that for spreadsheets etc. he misses the overview of the larger screen. He does conclude that it is possible for highly mobile people to use a PocketPC within meetings and perform daily tasks. An omission in this experiment (in our view) is the effectiveness effects.

Another experiment concluded that, besides the slightly impractical work posture, functionally the same can be done on a PocketPC as with a laptop, when the PocketPC is expanded with a full-fledged keyboard. A similar experiment has shown that replacing a laptop with a Palm device is technically possible and achieves quite acceptable results. However both experiments omit the effectiveness improvements/losses due to this construction. They are more proof-of-concept kind of experiments: is it functionally possible to replace a laptop with a PocketPC.

Some are less optimistic: they realize that when you really want some serious work done, you need at least a TabletPC. They acclaim that the PocketPC simply is not powerful enough to do complex tasks. I also performed my own experiment as well, realizing that although technically it is possible to perform all functions on a mobile device, its effectiveness can be seriously questioned. The experience of the platform and applications will never match a desktop.

Conclusion

PocketPC's certainly have huge benefits over laptops, especially for people that travel a lot. Most beneficial factors are the reduced weight and faster availability. In our opinion however, a PocketPC cannot replace a laptop: PocketPC and TabletPC/Laptop are complimentary devices:  PDA's are extensions of laptops, not replacements. For short interactions and lookups of data, a Mobile Device could replace the laptop perfectly; a PocketPC outperforms the laptop easily at such moments. But as a permanent replacement for a laptop, the PocketPC is not feasible. Although a PocketPC can perform the same functional tasks of a laptop, both research and practical experience have show that for real long-term effects the laptop/TabletPC holds the better cards to keep the interactions effective and medically acceptable. This is mainly due to the bigger screen and keyboard combined with a better physical positioning of the screen and keyboard, which improves effectiveness and reduces strain on people.