Software Engineering for Internet Applications - Student Community

In mid-2000, Webvan purchased HomeGrocer, acompeting grocery delivery company, andconverted the old HomeGrocer users to the newWebvan user interface. Orders fell by more thana $375,000-peryearfor liferetirementpackage.half. The HomeGrocer business went from breaking even to losinglots of cash simply because of the inferior usability of the Webvansoftware. Ultimately Webvan went bankrupt, taking with it $1.2 billionof invested cash.How is it possible that people follow what they imagine to be theirown good taste instead of either copying the successful Internetservices (e.g., Yahoo!, Amazon, Google) or listening to the users?And that people continue to believe in the value of their own ideaseven as the red ink starts to dominate their financial reports? JustinKruger and David Dunning, experimental psychologists at CornellUniversity, wondered the same thing and wrote up their findings in"Unskilled and Unaware of It: How Difficulties in Recognizing One'sOwn Incompetence Lead to Inflated Self-Assessments" (Journal ofPersonality and Social Psychology; Vol 77, No. 6, pp 1121-1134).Kruger and Dunning found that people in the 12th percentile of skillestimated themselves to be in the 62nd. Furthermore, theseincompetent people failed to recalibrate themselves when shown therange of performance by their peer group. The authors concludedthat "those with limited knowledge in a domain suffer a dual burden:Not only do they reach mistaken conclusions and make regrettableerrors, but their incompetence robs them of the ability to realize it."simultaneously on both the dedicated circuit-switched connection inuse for a voice call and also monitor GPRS frequencies for incomingpackets. In practice, GPRS may provide only three or four timesfaster throughput than existing WAP systems. More important is thefact that GPRS can, in theory, deliver an "always-on" experiencesimilar to that of i-mode or a hardwired desktop computer.As noted above, with GPRS the wireless Internet will become a placethat supports simultaneous voice and text interaction. For example,the following scenario can be realized:• User dials an airline phone number.• Airline: "Please speak your departure city"• User: "London"• Airline: "Please speak your destination city"• User: "Paris"• Airline: sends a WAP document via GPRS to the user'sphone, listing alternative flights• User: scrolls through WAP document, scanning with eyesthe flight times and prices, and picks with the phone keypadthe desired flight• ...Notice that voice prompting and recognition are convenient when auser is choosing from among hundreds of alternatives, e.g., theworld's airports. However, voice becomes agonizing if the user mustlisten to a long list of detailed choices--prompting with text may bemuch better when more than 2 or 3 choices are available, especiallyif each choice requires elaborate specification. Keep in mind "TheMagical Number Seven, Plus or Minus Two: Some Limits on OurCapacity for Processing Information" by George A. Miller (ThePsychological Review, 1956, vol. 63, pp. 81-97;http://www.well.com/user/smalin/miller.html).There is no evidence that the phone companies outside Japan willwise up to the power of revenue sharing. However, with theintroduction of GPRS the wireless Internet will become somethingbetter than a novelty. Seehttp://www.rysavy.com/Articles/GPRS2/gprs2.html for more on thesubject of GPRS.164185