Wednesday 26 September 2007

User interface façade

What does user interface façade mean, and is it a good thing?

Like all good philosophy essays, let’s start with some definitions so that we know what we’re talking about. A user interface is simply what a user sees when they are trying to make use of a piece of technology. The interfaces are usually completely inflexible. A user interface façade is very similar to a user interface in that it represents the presentation layer seen by the user. It is a way of giving the user an easy way of interacting with more complicated technology – or more usually software applications. What can make a façade more than a simple interface is the ability for the user to combine other interfaces and to have some control over the appearance of the interface.


So why would you want a user interface façade? Well, you can mask almost any technology with almost any design façade you want. Typically they are used to isolate a user working from a browser from the underlying CICS or other mainframe SOA application. The business units of work that are available on the mainframe can be easily used by an end user with little or no understanding of the technology that is being invoked on the mainframe. So in many ways a façade is a good thing.


Strangely though, the definition of façade is often negative. For example, http://dict.die.net/facade/ defines façade as, “a false appearance that hides the reality”; www.thefreedictionary.com/façade gives us, “an artificial or deceptive front”; and www.m-w.com/dictionary/façade defines it as, “a false, superficial, or artificial appearance or effect”. The printed Chambers dictionary even goes so far as to suggest, “the appearance presented to the world, esp. if showy and with little behind it”.


These all seem to be rather negative uses for façade, the last implying that all those years of mainframe effort count for nothing! I guess it’s similar to the term “legacy”, which in computing terms tends to mean something old and unwanted, whereas in more general usage a legacy is something you benefit from. Rich Aunt Agatha leaves you all her money – that’s a legacy you’re pleased to receive.


I guess that the big problem with user interface façades is that the original user interface on the mainframe has grown over time to suit the users (both new and experienced), and now a completely new one is designed that starts again. All that has been learned over the years with regard to how people feel most comfortable when interacting with the application is lost – and will have to be relearned for Version 2.0 of the interface. This seems like a waste of time.

Anyway, these thoughts about mainframe applications and user interface façades were stimulated by an e-mail from Anthony Rudd.

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