EPOC User Interface
Chapter by Nick Healey, Slash Design
Presented by Sasha Giacoppo
EPOC “platform”
A custom written software “platform” (OS+apps)
Designed for the Psion Series 5 PDA (ca. 1997),
but based on the Series 3 PDA original fxnality
Also intended for licensed use in other
Information Appliances
“targeted at maximizing the speed of access to
the information people wanted while mobile,
while minimizing the amount of UI to learn”
Designing EPOC
“support all the Series 3a’s functionality and
build on it”
“large-scale field research…would have been
impractical for a company of our size”
“All our ideas about usage patterns, key tasks,
users’ conceptual models, and so on were
informally generated by the company as a
whole.”
Deciding on the software
components of EPOC
New additions
WYSIWYG
Database mgmt
Flash disk support
PC agenda sync
Object embedding
Omissions
Multiple apps on screen
Handwriting recognition
Drag and drop
Universal password
protection
Data compression
As it turns out…
“all fell by the wayside because they [the omitted
apps] turned out, in our estimation, not to be quite
as beneficial or practical”
“In our estimation”…an educated guess vs.
scientific research…which would you rather rely
on?
So, in mid-1995, “after a false start in 1994”, a
year + later, an HCI design team was called in
1 Year+ later
 HCI team brought in…because of “far too many major
unknowns to make progress”, for reviewing the fxnality
of the apps
 Wrong thing to do, should’ve been there at the
beginning!
 Even after the HCI team was brought in, they still used
“Thought Police” to make decisions
 A lot of time/problems could have been avoided if a
more scientific process had been laid…as opposed to
the “shoot from the hip” method, which was documented
(no less by the London Business School!)
UI Design Principles in EPOC
Hide the Computer
Simple Language
Let users work their ways
Make the UI as Quick to Use as Possible
Make It Pleasant to Use
Protect the User
Hide the Computer
Hide the system model
Ex. Save changes function
Novices don’t need to see it
Experts can find/understand/use them if they want to
Hide complex or scary things
Complex/rarely used/intimidating items are hidden on
complex menus
Again, if a user wants them, they can find them
Simple Language
Use English, avoid technical jargon
Meaningful error messages
Let Users Work Their Ways
Don’t force one input method
Users can use screen or keyboard
Minimize the amount to learn
Consistent menu structures and dialogs across the
platform
Avoid cluttering
Plug and Play
Let user’s customize it their way
(If they want to)
Make the UI as Quick to Use
as Possible
Require as few user actions as possible
Dedicated buttons
Display the desired info as fast as
possible
Show as much of the user’s info as
possible
Agenda squashes up empty time slots
Make It Pleasant to Use
Don’t make the user feel stupid
Avoid blame-implying beeps
Try never to annoy the user
Delight the user
Record sound to set as alarm
Protect the User
Don’t let users shoot themselves
Hidden archive
Think what might go wrong, at each stage
Design Trade-offs in the
EPOC UI
Market Position vs. Range of Use
Usability vs. Power
Standards vs. Usability
Market Position vs. Range
of Use
Cannot just add features without
considering the effect on others
Application priority
Fun & games
Does more fxnality equate with market
position??
Usability vs. Power
Simple vs. Complex dialogs
Extent of toolbar functions
Does usability equate a decrease in
power (for expert users)??
Standards vs. Usability
Drag & Drop; Use of “file”; Templates
Deny usability for the sake of standards?
What I think…
Interface design issues were “decided on” or
“estimated” or “informally arrived at”
Considering this, the designers did a pretty good
job (these are smart guys), but…
Solid HCI research could have provided
definitive answers to many of the UI questions
Solid HCI procedures (e.g. incorporating HCI
during planning) could have saved much time
and many problems
Scientific methodologies could have provided
quantitaive answers during trade-offs