Slide 1Course UpdatesOutlinePerspectivesDefining Application-Led ResearchSelecting ApplicationsImplementing ApplicationsEvaluating ApplicationsRecommendationsSlide 10Allen Newell’s Research StyleGood science responds to real problemsGood science is in the detailsGood science makes a differenceSlide 15Mark Weiser’s VisionAre We There Yet?Did Their Work Have Impact?Next TimeSlide 20GoalsChallengesChallenge: Immense ScaleChallenge: Limited Physical AccessChallenge: Extreme Dynamics1EECS 598Wireless Sensor NetworksTechnologies, Systems, and ApplicationsLecture 2: Computer Science IssuesPrabal DuttaUniversity of MichiganJanuary 12, 20102Course Updates•Twitter feed for late-breaking updates:–http://twitter.com/eecs598w10•Writeups–Content looks good so far–If you decide to take a “pass,” send an e-mail saying so–Please send as e-mail plain text (no attachments)•Today’s office hours immediately after class•No class on Thursday, but writeups are still due!3OutlineWhat makes good application-led research?Picking research problemsComputer Science issues in Ubiquitous Computing4Perspectives•“Applications are of course the whole point of ubiquitous computing”–Mark Weiser [Wei93]•“We need to increase the applications deployed to books written ratio in sensor networks”–Deborah Estrin [Personal Communications]•“In the future, increasing proportion of computer science research will be application-driven”–Eric Brewer and Mike Franklin [CS262A]5Defining Application-Led Research•Application-Led Research–Driven by domain problem–Evaluated by quantifying benefits brought to domain•Technology-Led Research–Not necessarily motivated by potential domain benefits–Interesting or challenging from a technical perspective•Research Goals Should (do you agree?)–Identify users’ problems and application requirements–Provide infrastructure developers with application requirements–Validate technology and provides insights into its use6Selecting Applications•Will this change the way people think?–If nothing changes after your research, what’s the point?•Must make an impact on computer science–Just impacting biology or civil engineering is not enough–Starting from scratch can make this more difficult or easier•If system building, what will you learn from it?–There must be an important question in there!•Identify and attack “severe and persistent problems”•Avoid trivial “proof-of-concept” research projects–Team up with domain experts when selecting problems–Make sure there’s a concept and it’s worth proving7Implementing Applications•To start from scratch or not?–Benefits?–Drawbacks?•Is building reusable infrastructure worth it?–Research community values novelty over good engineering–Research community doesn’t value implementation as research–Do you agree?•Reframe the question: What are your options? (Aside)–Your efforts can be directed structurally or strategically•Structural: change the community so that it values infrastructure•Strategic: pick the right topic, and your work will be broadly used (and well referenced)8Evaluating Applications•Small, lab-scale evaluations–Useful: in the early stages of design–Insufficient: impossible to understand the impact of•Environment on technology•Technology on environment•Often hard to teach these apart – hence “systems” research•Applications are evaluated only against themselves–Self-evaluation is insufficient–Requires applications, infrastructure, and data to be shared•Is this a good idea?•Is it done in other fields?9Recommendations•Choose applications carefully–Address severe persistent problems; avoid trivial ones•Share technical infrastructure–Design reusable SW/HW; publicly release code•Evaluate applications in realistic environments–Only way to investigate interactions between tech/env/users–“The real world is it’s own best model” – Rodney Brooks•Perform comparative evaluations–Release data sets from field trials; allows other to analyze10OutlineWhat makes good application-led research?Picking research problemsComputer Science issues in Ubiquitous Computing11Allen Newell’s Research Style•Good science responds to real problems•Good science is in the details•Good science makes a difference12Good science responds to real problems•Don’t pick fantasy problems•Don’t pick trivial “proof-of-concept” problems•Too many real pressing real-world problems!•Pick “severe and pressing” problems13Good science is in the details•Takes the form of a working model–The artifact is about understanding, not building–Must build when analysis is too complex–Brooks’ quote: “The real world is its own best model”•Includes detailed analysis or implemented models–Allows others to benefit from work at an abstract level–Enables comparisons between difference approaches14Good science makes a difference•Measures of contribution:–How it solves a real problem–How it shapes the work of other•Solves a real problem–The problem sets the crucial context for the work–A million ideas to pursue, but which ones are worth doing?•Shapes the work of others–Highest goal: change other people’s thinking–Paradigm changes are the most impactful [Kuhn]15OutlineWhat makes good application-led research?Picking research problemsComputer Science issues in Ubiquitous Computing16Mark Weiser’s Vision•Who is Mark Weiser?–Michigan alumnus: MA(‘77), PhD (’79)–Father of ubiquitous computing–Work is incredibly influential•What are the principles of ubiquitous computing?–The purpose of a computer is to help you do something else. –The best computer is a quiet, invisible servant. –The more you can do by intuition the smarter you are; the computer should extend your unconscious. –Technology should create calm.17Are We There Yet?•Hundreds of Tabs?•Tens of Pads?•One or two Boards?18Did Their Work Have Impact?•Yes! Due to emphasis on computer science issues:“The fruitfulness of ubiquitous computing for new computer science problems justified our belief in the…framework”•Issues like–Hardware components•Low power (P=C*V^2*f gives lots of degrees of freedom)•Wireless (custom radios (SS/FSK/EM-NF bits/sec/meter^3 metric)•Pens (how do you write on walls?)–Network Protocols•Wireless media access (MACA: RTS/CTS)•Gigabit networks (lot’s of