Operating Appliances with Mobile Phones - Strengths and Limits of a 
Universal Interaction Device 

Christof Roduner and Marc Langheinrich and Christian Floerkemeier and Beat 
Schwarzentrub Institute for Pervasive Computing, ETH Zurich, 8092 Zurich, 
Switzerland 

Abstract 

Mobile phones are increasingly becoming ubiquitous computational devices that 
are almost always available, individually adaptable, and nearly universally 
connectable (using both wide area and short range communication capabilities). 
Until Star Trek-like speech interfaces are fully developed, mobile phones seem 
thus poised to become our main devices for interacting with intelligent spaces 
and smart appliances, such as buying train passes, operating vending machines, 
or controlling smart homes (e.g., TVs, stereos, and dishwashers, as well as 
heating and light). But how much can a mobile phone simplify our everyday 
interactions, before it itself becomes a usability burden? What are the 
capabilities and limitations of using mobile phones to control smart 
appliances, i.e., operating things like ATMs or coffee makers that typically 
do not benefit from remote control? This paper presents a user study 
investigating the use of a prototypical, mobile phone-based interaction system 
to operate a range of appliances in a number of different task settings. Our 
results show that mobile devices can greatly simplify appliance operation in 
exceptional situations, but that the idea of a universal interaction device is 
less suited for general, everyday appliance control.