MetaCard Development Report

Notice:

Background:

The Ice-cream Bar shall let the customer choose how many scoops of ice-cream to buy. It shall offer 10 different flavors of ice-cream, 4 kinds of granules, 4 kinds of sauce and 5 different extra accessories.

Since some customers find it very difficult to handle screens with many elements, the choices should be limited to keep down the number of screen elements of the interface.

Assumptions:

I have made these assumptions about the system:

• This is an ice-cream vendor machine, customers pay with "plastic cards"
• The machine is placed indoors, so there is no need to accomodate customers wearing gloves.
• The users are for example shoppers in a mall or students in the cafeteria.
• The customer can choose to buy up to four scoops of ice-cream.
• All communication is via the screen, wich is a color touch screen with resolution 640x480.

First sketch:

All choices are made on the same screen which has a large number of different elements.

All choices are done in different ways, and there are many opportunities for mistakes. If the user makes a mistake, a cryptic error message is shown.

Notice that this design has a keyboard for entering text.

You shold imagine that the text has different fonts and different colors, and the backgrounds of the screen elements have different clashing colors.

Design:

• The user makes only one choice on each screen
• All choices are made by pushing buttons
• Only those buttons are shown that are available at the moment
• All text is black, using the same font and a limited number of sizes
• A limited number of colors are used
• There is always opportunity for the user to change his mind

If you want to know what my design looks like, download the MetaCard file Bjglass2.mc or the Windows 95 executable Bjglass2.exe (553 KB zip file).

Or you can look at the pictures from the Swedish version of the MetaCard Work.