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Studying The Use of Handhelds To Control Everyday Appliances. Jeffrey Nichols Carnegie Mellon University August 24, 2001. The Problem. Interfaces to appliances are becoming more complex. Stereos, televisions, microwaves, alarm clocks, telephones, VCRs, etc.
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Studying The Use of Handhelds To Control Everyday Appliances Jeffrey Nichols Carnegie Mellon University August 24, 2001
The Problem • Interfaces to appliances are becoming more complex. • Stereos, televisions, microwaves, alarm clocks, telephones, VCRs, etc. • Little standardization among similar appliances.
The Solution • Observations • Many people now carry a handheld device. • Mobile phone, Palm, PocketPC • Handhelds have richer interface technology… • Large LCDs, touchscreens, text-entry • Solution • Move the interface from the appliance to the handheld!
The Personal Universal Controller • The appliance and the handheld will have two-way wireless communication. • Each appliance will have a built-in specification that is sent to the handheld, which then generates an interface. Specifications Control
Benefits • The interfaces take into account: • user preferences • conventions of the handheld device • other interfaces that the user is familiar with
Outline • A First Step • User Studies • Future Work
A First Step • Build Reference Interfaces • Remote control interfaces for various appliances that we design manually. • Verify that better interfaces can be created on a handheld • Used for understanding what functional knowledge is necessary to make a good interface.
Reference Interfaces • Interfaces were hand-designed for two appliances and two handhelds • Appliances • AIWA CX-NMT70 Shelf Stereo • AT&T 1825 Telephone/Answering Machine • Handhelds • Palm • Microsoft PocketPC
Palm Interfaces We initially designed paper-prototype interfaces for Palm telephone stereo
PocketPC Interfaces We later implemented interfaces for Microsoft’s PocketPC (simulated remote control). telephone stereo
Interface Quality? • We iteratively improved the interfaces using heuristic analysis techniques. • We conducted a think-aloud study with several Carnegie Mellon students to find problems in the interfaces. • Lastly, we conducted a user study that compared our reference interfaces with the manufacturer’s interfaces.
Outline • A First Step • User Studies • Future Work
User Studies • Two Studies • Study #1: Paper-PrototypePalm vs. Actual Appliance • Study #2: Functional PocketPC vs. Actual Appliance
User Studies, cont. • Procedure • We did a between-subjects study. • Each subject worked on two sets of tasks. • In order to minimize subjects, each worked on both the stereo and the phone. • We controlled for order and interface type.
Evaluation of Task Performance • Three Metrics: • Time to complete all tasks • Number of times help was requested • How often did the subject need the manual or online help? • Number of missteps • Misstep = the pressing of a button that does not advance the progress on the current task • No missteps were counted after the user requested help.
User Study #1: PalmOS • Paper-prototype study • Good results • Users made 1/5 as many errors and requested help 1/2 as often with the handheld interfaces • This was encouraging, but… • We wanted to verify these results with higher fidelity interfaces
User Study #2 • We implemented the interfaces on a handheld and simulated remote control of an actual appliance. • Remote control applications built in Visual Basic on a PocketPC • Control of stereo and phone simulated in software • Feedback appeared to come from the actual appliance
User Study #2, cont. • Participants • Twelve students from Carnegie Mellon • Four female, Eight male • Volunteered in response to a newsgroup advertisement • Paid $7 for their participation (30-45 minutes) • All had limited handheld experience • Half (6) owned Aiwa-brand stereos • Two had AT&T digital answering machines
User Study #2 Results All differences are significant (p < 0.05) About ½ the time and ½ the errors!
Qualitative Results • Why were the reference interfaces better? • Disabled elements were not always shown on the screen. • Less-used functions could be hidden in menus or dialog boxes. • Labels could dynamically change. • Clear feedback and explanation of the current state was possible.
Outline • A First Step • User Studies • Future Work
Future Work • Build more reference interfaces • We will create more interfaces to be sure that we understand as many of the features of remote controls as possible. • Copy machine • Microwave oven • MP3 player
Future Work, cont. • Design a specification language • This is currently in progress. • Information currently in the language: • State variables and commands • Grouping tree • Dependency graph • Lots and lots of labels
Future Work, cont. • Build an automatic interface generator • Determine the structure of the interface • Choose interface widgets for each state variable and command • Layout the widgets on the screen
The End… • For more information see… • http://www.cs.cmu.edu/~jeffreyn/ • http://www.cs.cmu.edu/~pebbles/ • Or e-mail me at… • jeffreyn@cs.cmu.edu
Actual Appliance Interfaces • Lots of Problems • Poorly labeled and overloaded buttons • Insufficient feedback • Timer example • Programming the speed-dial • Phone has technical separation between phone and answering machine
Qualitative Results • Grouping controls is important • Groups define which elements are placed adjacent to each other and how elements are separated onto pages. • Groupings vary between devices and interface styles.
Qualitative Results, cont. • Dual-associated functions are hard to make obvious for users • The record button is associated with both tapes (record onto) and each of the other modes (recorded from). • Some users expected the first mapping to used, whereas the controller used the second mapping.
Qualitative Results, cont. • Tree-based structures are not sufficient for fully describing an interface • Some interface concepts, especially dual-associated functions, break the tree because they may interact with the children of several different elements within the tree • The record button breaks the stereo’s tree structure because it is globally accessible but has different local effects.
Qualitative Results, cont. • A single function may map to multiple interface widgets (and vice versa) • Example: One state variable could be used to represent all of the playback states of a tape player. The play, stop, fast-forward, and rewind buttons all act on this single variable.
Applying These Results • We are actively applying these results to the design of the specification language • A tree-grouping structure is augmented with a dependency graph to help describe dual-mapped functions • Ranking relationships within groups using “priorities” • We will also apply them in the design of the automatic layout engine
Future Work • Build the specification language and automatic generation engine
A Hard Problem… • Automatically generating a good user interface is hard, but we think we can do it for several reasons: • Remote controls are a special class of user interface that use relatively simple interaction techniques. • Buttons, text fields, and other standard widgets. • Our approach differs from earlier work…
The Approach • Study Interfaces • Functional knowledge of the appliance • What must the appliance tell the handheld about itself so that a “good” interface can be constructed. • Design and Layout • How do we turn the knowledge about the appliance into a usable interface? • Design a specification language • Build an automatic interface generator
Our Progress… • Study Interfaces • Functional knowledge of the appliance • What must the appliance tell the handheld about itself so that a “good” interface can be constructed. • Design and Layout • How do we turn the knowledge about the appliance into a usable interface? • Design a specification language (in progress) • Build an automatic interface generator
User Study #1: Extra Slides • Participants • 13 Carnegie Mellon graduate students • Five female, Eight male • Enrolled in School of Computer Science • Seven owned a Palm device • One had no Palm experience • Four owned Aiwa-brand stereo systems
User Study #1 Results Users made five times the errors and needed help twice as often with the actual appliances! All results significant (p < 0.001 for all)
Problems with User Study #1 • Paper-prototype study introduced a high possibility of experimenter interference. • Solution • Create an environment that completely simulates what one might experience using a personal universal controller • Interfaces running on an actual handheld • Interfaces should appear to control an actual appliance
James went to the bathroom • He will return in a moment. 11:16am