Research Results Design lessons [IEEE Pervasive, 9/02] Systems Issues [Pervasive’02] Evaluation [Consolvo, Ubicomp’02] H.S. Education application
Design Lesson: UI before AI Relative Utility Flexibility Take 1: summer ‘00 Sensor driven Plan recognition Emphasize flexibility Take 2: summer ‘01 UI driven Plan representation Distributed/Robust/Reliable summer ‘02 Flexibility Usability Proactivity (w/ Asst. Cog.)
Design Lesson: Values Matter Exploratorium (HP CoolTown) Kids and lay people doing science experiments Value is in the experience Interface became implicit at expense of functionality, quality UW Immunology Lab (Labscape) Professionals doing biology experiments Value is in the results Interface became explicit (the physical platform may disappear!)
Design Lesson: The Rubicon Users should not have to “cross the Rubicon”. The true essence of invisible computing. Our design goal: 100% task focus. All interactions with Labscape result in domain benefits to the user. Automatic persistence (no explicit file I/O, etc) Tolerate disconnection Dynamic reconfiguration Robust Available (like gas, water) Responsive Distributed
System Architecture Asynchronous communicating components
one.world Runtime Env. [Grimm] environment Tuple Store Component = collection of event handlers. No threads (except AWT), open connections, etc. Environment: a padded cell for components Node A Node B Change Discovery (late binding) Asynchrony and notification Migration Checkpointing Composition Remote events Environments (interposition) Sharing Tuple Store Events over Standard IO
Exploiting one.world environments Client Device A Labscape User2 Replication Device Access Client Device B Server Root Labscape Database Prox. Service ack validate update node tag user tag version ack multicast one.world discovery
Ubiquitous Access: Migration Virtual Terminal Low latency, low performance Easy but inadequate Does not support disconnection State Migration Move all model and some view state High latency, high performance Easy in principle but fragile State Replication Low latency, high performance Potentially high cost unless we are smart about it Some is necessary. Hybrid approach will be best App developer: trade-offs between what and when. Not how! We need ocean store!
Result Stable Fast response (all local speeds except DB query) Migration strategy evolving. Built-in mechanisms not good enough… Disconnection/standalone OK. May have conflict resolution problems, but usually single writer! Dynamic reconfiguration yes. Location sensing, no. Replication works. Multiple users w/ different views of same model stay in synch Instrument interfaces are a huge problem. Just have file system snooper now. Seems scalable and evolvable (maintainable)
Evaluation Goal: Do no harm! Assess impact on key aspects of user ubiquitous computing user experience Does it increase interleaving of information utilization with physical activity? Does it decrease thrashing associated with lack of readily available information? Does it make new things possible?
Ballard HS Experiment Concept: Integrate Theory and Practice Does it improve learning? Are requirements different?
Student 1 Staining with EtBr Allows pictures to be made of the gels Unexpected result? Pipetting error Thermalcycler busted No DNA Ran the gel too long Staining with EtBr Binds to DNA and fluoresces under UV light Unexpected result? Forgot to load DNA - no bands Forgot forward/reverse primers - no bands Too short running time - Results not definitive Too high DNA concentration - a big bar (smudge)
Student 3 Incubating at 100C - thoroughly breaks the chelex so it'll attach onto all DNA cells dNTPs – I don't know what it stands for EtBr – used to stain the gel to keep all data on the gel Incubating at 100C - breaks open the cells to release the DNA dNTPs – This is the most important reagent, because it creates all the guanine, thymine, As and Cs for the DNA strand EtBr - sticks onto the DNA and helps the analyzer see the results with UV light
Interview Less magic Less text to read!? Better conceptual integration
Deployment CSI Marginal regular use Immunex Amgen User study phase. Ballard High (Seattle Public Schools) Successful pilot study completed Lisa Jenschke, director of educational outreach for CSI Summer push: editing, math/control, usability, import/export, etc. DARPA NSF NIH Intel MSR
Dynamic Reconfig: Indirection First try (java sockets): Device proxies make connections to app over sockets. Proximity system sets up connections Fragile, costly Second try (one.world): Asynchronous messaging w/ indirection through late-binding discovery Increased latency (minor issue) Lost of in-order delivery guarantees (major issue) Robust, scalable System has to provide many delivery options and different guarantees. App developer chooses
Automatic Persistence Fail safe persistence w/ local responsiveness Stand alone operation Reconnect Synchronization Multi-user synchronization Key: separation of concerns