1. Case Study: Choosing an Exercise Mode in a Heart Rate Monitor
Adapt Or Not To Adapt
Case Study: Choosing an Exercise Mode in a Heart Rate Monitor
Lauri Sumari 2002

2. A Definition
Adaptive systems are systems which can alter aspects of their structure, functionality or interface in order to accommodate the differing needs of individuals or groups of users and the changing needs of users over time
– Benyon et al. (1987)

3. Case: Heart Rate Monitor UI
tested in the usability lab
a pro model
many features
comes with a PC utility
challenging constraints
small screen
few buttons
only one menu item visible at a time

4. The Problem the monitor has 10 different exercise modes
a pro user uses many modes regularly
many exercises each day
the mode must be chosen each time
tradeoff: detailed data / input effort
how to select the default exercise mode?

5. Key Characteristics a menu with many items
only one item can be shown at a time
default item carries most weight
measurable variables correlate with menu item usage
correlation is user-specific
correlation changes over time
machine learning?

6. Attributes of a Solution
menu order?
fixed, configurable, sorted
default item?
item number 1
most recent item
most frequent item (adaptivity?)
most likely item based on context (adaptivity)

7. How to Make the Choice? is the problem "hard enough"?
is the adaptive approach feasible?
limited processing power
limited memory capacity
what is the most usable solution?
missing heuristics / design patterns
must analyze options for both approaches

8. A Conventional Solution
menu order: fixed or configurable
default item: most recently used
predictable
easy to implement

9. An Adaptive Solution menu order: fixed or configurable
default item: most likely
operational life cycle
initial phase
transitional phase
mature phase (watch out for abrupt change!)

10. Building the Adaptivity
context variables
day of week, time of day
idle time, recent choices
current heart rate
pre-training at the factory
tradeoff: head-start / miss penalty

11. A Critical Look the adaptive approach currently overkill
but look at the future of adaptivity
more common?
reusable frameworks for implementation?
similar usability challenges likely
small computing devices proliferate