In-flight entertainment systems – Part 2a (User interface paradigms)

Introduction

In part 1 of this review (http://geekswithblogs.net/twickers/archive/2006/02/15/69535.aspx) I provided an introduction to the handsets used by Air New Zealand and Virgin Atlantic systems.  In this part we cover how the features offered by those handsets are utilised to provide the user interface.  This has been split into two separate posts due to the amount of content involved; here we cover the Air New Zealand system.

The simplest means of describing the two differing approaches to designing a user interface is to examine their similarity to more familiar technologies.  The Air New Zealand system uses a web browser metaphor, based on selecting ‘links’ within the interface by moving an on screen selection device.  The Virgin Atlantic system is more similar to using a DVD menu system or a Macromedia Flash interface where ‘on screen buttons’ change colour as they are highlighted and colour coded ‘shortcut’ keys are displayed as on screen items.

User interfaces

Air New Zealand

Interestingly, our first introduction as passengers was an announcement by the flight crew not to press buttons too quickly as it can cause the system to hang.  So, even before we got our hands on the system we had our expectations lowered. I didn’t personally try overloading the system with manic key pressing; the prospect of 11 hours without an entertainment system was too grim a scenario.

For anyone who has used the Liberate interactive television system the Air New Zealand interface will feel familiar.  Here in the UK that means Telewest and NTL subscribers, in Europe UPC subscribers, and the same system was also used by some US cable services.  The kernel of the Liberate system was based on the Netscape 3 browser, with specific extensions for handling video and audio, such as displaying video in a window.  This allows pages to be created in standard HTML tools with the ability to use JavaScript to provide more complex functionality.

I would suspect that the Air New Zealand system, while probably not being a Liberate system, has a very similar framework.  It uses a cut down web browser to provide the user interface.  With no mouse to select links, an on screen selector device is used.  A gold/yellow rectangle (very Liberate) can be moved between active links with the cursor pad on the handset.  The gold rectangle can be moved in all four directions, and a press of the button in the middle of the cursor pad is used to ‘click’ the highlighted item.

Air NZ User Interface

The concept behind this user interface is fundamentally sound.  Reusing browser technology can provide faster authoring of new pages using tools familiar to web designers.  However, using a browser which is not designed for cursor navigation between links is not trivial. The browser has to intelligently move the cursor, calculating which link should next grab focus depending on the direction selected. 

As an end user this can result in what appear to be fairly random selections at times.  Quite often when moving up a screen, instead of the next item selected being the link that has the ‘majority’ of content above the current item, it selects an item above and to the left or right of the item you were trying to select.  It gives the impression that the link selection logic is based on a single point algorithm (such as top left comparisons) rather than using comparisons of the bounding rectangles of the links on the page.

Random link selection breaks a cardinal rule mentioned in a previous post, Don’t make the user feel stupid. 

Moving between links on web pages using cursor keys is implemented by other devices. Pocket Internet Explorer on the Windows Mobile Smartphone platform has used this approach for some time.  However, I believe Pocket IE is more successful, with a less invasive on screen selector and more logical movement between items.  The smaller screen of the Smartphone platform may actually help here, as it constrains the number of options for automatic link selection.

However, the fact that Windows Mobile achieves sensible navigation even on pages not specifically designed for the platform makes the eccentricities within the Air New Zealand system even more unacceptable. With an in flight system the operator has complete control on the design of screens and theoretically should be able to create layouts which can be navigated logically.

Finally, brightness control on the LCD display is can be controlled from the handset. There was no instructions on how to achieve this in the in flight magazine.  I somehow managed to hit the correct button by luck.  If I remember right you had to guess that you should press the ‘b’ button (for Brightness? if you speak English, of course).  After pressing ‘b’ an on screen menu appears allowing the user to adjust the brightness level with the cursor keys.

Coming up

User interface paradigms (2b - Virgin Atlantic), Video on demand (VOD), Music playback and Games, Conclusion.

[apologies for the delay in getting this post you, I recently got swamped with work from clients, and these articles took a back seat, however, I promise, Part 2a will be out by next week]

Print | posted on Wednesday, March 15, 2006 5:49 AM

Feedback

No comments posted yet.
Post A Comment
Title:
Name:
Email:
Comment:
Verification: