Interaction scripts
Guest blog by Dave Ellender.
Interaction Scripts are a nifty technique for specifying software applications – without getting bogged down in requirements documents, use cases or wireframes.
A few sides of A4 illustrated with some key wireframes can readily describe the full range of functionality of a rich desktop or web-based application, including drag and drop, sound effects and indeed anything else. All you just need is a little structure for the words you write! Trying to do the job just with wireframes alone can typically require dozens and dozens of, er, wireframes.
Create-a-Scape
In 2006, as part of futurelab’s Create-a-Scape project, I observed many children using a desktop software application called the Mobile Bristol Toolkit, made by Hewlett-Packard (HP). Afterwards, I was asked to make recommendations for a new version of the Mobile Bristol Toolkit.
Agile… by another name
I needed to do this quickly – I think I had two days after our meeting with HP – so I decided to try using User-System Interaction Scripts (to give them their full name). This was partly because I knew the developers at HP would ‘get it’.
So what are interaction scripts?
User-System Interaction Scripts are exactly like scripts used in for plays, films or television dramas. Here is part of one of my old favourites:
OPHELIA
Good my lord,
How does your honour for this many a day?
HAMLET
I humbly thank you; well, well, well.
OPHELIA
My lord, I have remembrances of yours,
That I have longed long to re-deliver;
I pray you, now receive them.
HAMLET
No, not I;
I never gave you aught.
Don’t worry… you don’t have to be Shakespeare!
1. You don’t have to name your characters…. they are called user and system
2. It is easy to write… it’s not Shakespeare, just Plain English.
3. It is easy to read… it’s not Shakespeare
4. You can specify what the user does and what the system does at whatever level of detail is convenient. This is what gives the technique a lot of power: you can describe things in a lot of detail or a little – depending on how much time you have to do the job, how much you know from user research, whether the user interaction is ‘standard’ or novel.
An example: Copying words
The example illustrates how users can copy words in a word-processing application. A number of user tasks could be scripted in this way to form a specification for a new application. Add a few wireframes to display the interface design (e.g. menu, toolbar, clipboard) and, as we say in Bristol, “job’s a good’un”.
(One notable difference with the type of scripts used dramatically is that alternate actions can be provided at each stage of the interaction. Playwrights don’t really go in for sort of thing.)
COPYING WORDS
a. User double-clicks a word
a2. User drags cursor over a word
b User selects edit menu and menu item Copy
b2. User presses control-C on keyboard
b3. User selects Copy icon from toolbar
b4. User drags word onto clipboard
c. System adds selected object to clipboard
So, whose idea was it?
Two Microsoft employees, R. Spencer and S. Clarke, described this technique in a very good recent book called ‘The Handbook of Task Analysis for Human-Computer Interaction’.
Find out more:
futurelab’s Create-a-scape
Hewlett-Packard’s Mscape
The Handbook of Task Analysis for Human-Computer Interaction
Wireframes
Task Analysis
About the author
Every now and then cxpartners asks other user experience professionals to write a blog for us. Email cxpartners, or call +44 (0)117 946 3930
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