General Usability Issues - Guidelines For Design; Mobile Applications For Mobile Use; Validate Your Wml; Site Organization - Nokia 6210 Developer's Manual

5. GENERAL USABILITY ISSUES – GUIDELINES FOR DESIGN
Nokia phones are renowned for their ease of use and intuitive user interface. In order to create a
service that will be perceived as usable and easy to understand, Nokia Mobile Phones provides some
general guidelines to help service providers develop their applications.

5.1 Mobile Applications For Mobile Use

When deciding what information to include in the different applications on a mobile terminal, think
about which information might be relevant in the situations where the Mobile Phone will be used.
Because of the mobility of the small display, the user might primarily use the Mobile Phone when there
is no access to the Internet on a PC. We believe that users of the mobile applications will primarily be
interested in brief and quick information. For instance, quick access to flight schedules from the Mobile
Phone might be relevant for a user. Similarly, several short news flashes are more relevant than longer
news articles. Quick access to weather information may also be of use in the mobile situation to
quickly check out the temperatures of the destination of the traveller. However, it is less likely that
users will surf on the application on the mobile terminal, but will prefer to surf the Internet on a PC
from their office or home.

5.2 Validate Your WML

There are several XML validators available that validate your documents against WML Document Type
Definition. It is recommended that authors validate their WAP pages, because invalid WML is always
treated as an error and discarded (ie. not shown to the user!).
Several XML validators can be found at http://www.wapdevelopers.org/xml.tpl?CALLER=index.tpl.

5.3 Site Organization

5.3.1 Avoid 'doormat' pages
The user is accessing your WAP site over a GSM data call, and pays per second. It is not recommended
that you start your site using a 'doormat' page, which has no functionality other than perhaps to greet
the visitor and to display a logo. It is better to go to your service directly. If there's a need to use the
timer it shouldn't be timed for longer than 1.5 s, otherwise add a 'continue' link to give the user the
possibility of exiting the card.
5.3.2 Automatically Detect the Browser
If you are using a modern web site hosting environment, it is possible to detect the browser as well as
the language mode and supply the correct content transparently, without user interaction.
5.3.3 Optimize for Size
The size of the content is critical. If you have large decks (listings, large tables, etc.), consider splitting
them into multiple parts for faster downloading.
As for the total download time, some studies place an upper limit for acceptable delay at 10 to 15
seconds, including all images, on a PC-based browser. It is highly recommended that there be a
response time (excluding connection time) of less than 10s in a mobile environment.
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