Guide to writing Multimedia Software

Introduction

Here at Cheshire Interactive Technology, we are very keen that all kiosk projects are successful, whether they use our kiosks or not. We believe that the kiosk market is really beginning to take off and that the more quality systems that are sited, then the faster the market will grow.

To compliment our well developed hardware range, we have produced this brief guide to enable our software developing partners develop their software. This guide brings together all the experience of Cheshire Interactive Technology over the last 15 years.

It must be recognised that what constitutes a good multimedia application is very subjective. Since this is an emerging market, there will be success stories and those that do not do so well. Hopefully this guide will lead to more winning projects.

Structuring a Multimedia Program

There are three parts to a multimedia program;

· the foreground which the user directly interacts with,

· the background software hidden from the user, e.g. printer driver, database contents,

· the maintenance mode. This is often overlooked but is one of the most important.

The foreground has two elements, the attract mode, a sequence of screens with moving graphic to attract people to the screen and show the unit is working and the play mode, the main program entered once the screen is touched anywhere in the attract mode.

The 'attract mode' consists a number of screens which;

· prevent screen burn

· explain to the potential users what the kiosk offers them

· help on how to use the system

· what to do to start using the kiosk

· attract people to the unit, e.g. an MPG video clip with sound

The Cheshire Interactive Technology test for a good kiosk program is "Can a user satisfactorily interact with the unit within 14 seconds", i.e. can he / she make a correct selection by touching the right button and bring up on the screen what he / she expected ?.

Deciding the Scale of the Program

Applications fall into one of two categories;

· single offering (e.g. Citroen), customer crystal clear as to which product / services are on it

· multiple offering, customers may get confused as to what kiosk is offering.

There will be a financial decision to be made, for example, if you put more than one offering on a kiosk, then the cost of the kiosk and servicing can be split between those companies who have product on the kiosk. If the kiosk is for a single application then we would suggest that an artificial level is put on the scale of the program for number of reasons:-

· e.g. if you listed every CD ever published, the database would be huge, taking up lots of hard disk space. Search times would be unacceptable, people would spend too long doing endless searches. If your contents/database had say 1% errors, then on 10,000 entries you start to have unacceptable levels of entries.

· accept that the authoring package or language you are using will have limitations (which may not be published)

User Interaction

The most common interaction is via a touch screen and touch active buttons. Following on from this there are two approaches:-

· tree structure

· scroll & select

The approach adopted for the customer to use is decided be the program's designer and must suit the type of clientele who are likely to use the kiosk. e.g. are they 'Windows' literate and comprehend scroll bar interfaces

Preparing Assets

The software requires careful structuring and laying out of graphics to have the right "feel", areas to pay attention to include;

· use of colours

· buttons; size, shape, how many etc.

· sound; how much and when to use it ?

· number of levels

We shall now look at a number of these in more detail;

Video

The most common method to show video clips as part of a multimedia presentation is to use MPEG. Since this is a compression technique, some detail from the original video quality is lost. Therefore, if you start with an 'average' quality video sequence and digitise it, on playback the quality will be poor. However, if you start with a 'high' quality video sequence and digitise that, the playback will be better.

Still Pictures

Again, new technology has made an impact on the processing of images. Until quite recently, you used an existing photograph and had it scanned in, and converted to a file format of your choice (TIF, GIF, BMP etc).

Now you can use a digital camera and import the picture directly into the computer - No developing, no scanning. Since less processing work is being done, the picture quality is not diminished.

Colour

As computers have become cheaper, their specification has increased and in particular the number of colours available and the screen resolution. Whilst graphics designers can create superb images and effects, the end user needs to be borne in mind.

If a company's logo is to be used, then the image should be carefully reproduced using the correct colour, font and symbols.

Where colours are used to emphasise headings, then their use should be consistent throughout.

Sound

Sound when used correctly can be a very important asset to a kiosk system in a variety of ways;

· it can be used periodically in the attract mode to stimulate interest

· can signal that a button has been selected correctly,

· can signal that a poor selection has been made on the screen,

· used to convey the message; e.g. sound track on a CD selection.

Buttons

Points to bear in mind;

· Remember, most people are right handed, so either layout buttons on the right or in the centre

· People read from left to right and logically put the button at the end of the text rather than at the start, otherwise their eyes have scan back to the left to make the selection

· Don't use buttons that are the same size as windows icons; people need at least 1" square buttons to reliably hit via a touch screen

· Don't put animation within a button. Whilst the graphics are moving, users will be reluctant to interrupt them

· The psychology of perception is that people view 'items' against a background. For example, this is printed text in black on a white sheet of paper; the close the foreground and background are, the more difficult it is to differentiate the buttons

· If you have 4 buttons on a screen and you ask someone to select one, there is a 25% chance of them touching the one they want, but 75% chance of them touching the wrong one. The lesson here is, the more buttons you have, the higher the probability of touching the wrong one

· We believe that users need to be able to make a selection within 14 seconds, otherwise they will decide the unit is too difficult to use

· Don't put buttons in the corners of the screen - they can be difficult to touch and read from the side of the kiosk.

· Remember, when 'touching' a button on a touch screen there is no feedback. You either need to make a 'beep', alter the colour of the button or use small animation such as a drop shadow. This provides feedback to the user that the touch has been accepted.

· The use of the buttons will be enhanced if their layout is kept consistent. If you have a button called 'Proceed' then do not move it's position around the screen. People like things they see to be 'stable'

· The colour of buttons is important:-

· green is a 'go' condition and safe

· red is a 'stop' condition, used as 'delete'

· grey is neutral and does not draw the eye

· Once a button has been assigned a colour, don't change it's colour between screens

Maintenance Mode

· service access door to kiosk is opened, triggering a microswitch with contacts connected back to the PC,

· opening the kiosk and pressing ESC on the keyboard,

· entering a secret password / code via the touch screen,

Its purpose may be one or all of the following;

· to enter new data into the database used by the application, e.g. new prices, stock levels,

· download or export the usage statistics to a floppy disk for off-line analysis,

· run SCANDISK and DEFRAG to tidy up the hard disk and optimise performance,

· calibrate the touch screen.

The maintenance mode is "left" or exited by a button on the menu page of the maintenance mode, taking the software back to the application

Testing

Whilst it is unlikely that any program is totally bug-free, it does need to be robust when used by the public and present a quality image about your company. Software programmers are the worst people to test software, since they will only test how they believe it operates. Also you need some methodology to test the software reliably

Simple Testing

· If the software asks for a 'number', check:-

· entering a number outside high/low limits

· entering a negative number

· entering characters

· entering other symbols

See how the software responds and if it recovers

· Leave it running for a week, see if any counters/timers overflow

· Switch the machine off part way through the program and see if it re-starts okay. (someone is very likely to do this in a real environment)

· Have a test machine that will check if every title that is listed in the database actually exists, and thus avoid the 'title not found' error message

All conceivable errors need to be trapped and dealt with. If the error is fatal, then you need to advise users that the unit is 'temporarily unavailable' which is a lot better than a corrupt or blank screen

Version Control & Testing

not only will the program go though many stages of development, it will need updates whilst in operation

Reasons for updates may be:-

· new company logo to appear on screen

· phone numbers may change (e.g. 061 to 0161)

· video footage out of date

· products or services may become withdrawn

If you operate a small number of tasks, then managing the software can be quite easy. As the projects get larger and the task become more onerous

We recommend that in the diagnostics or maintenance mode, that a table is available showing:-

· date of last update

· revision of main routines

· revision of database

As more updates are carried out, the disk will become fragmented, slowing down the program. Not only must SCANDISK be run periodically, but DEFRAG as well

Interacting With Peripherals

I take a peripheral to be an appendage to the kiosk which requests a software interface

Wherever possible, select a device which uses a standard interface and a suitable driver where appropriate exits.