Showing is not explaining

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Pat Hanrahan's Tapestry Conference 2013 short story slide presentation

Text of Showing is not explaining

1. Showing is not ExplainingPat HanrahanStanford and TableauTapestry 2. Euclids Algorithm**First known algorithm 3. Greatest Common Divisor2, 3, 4, 6 divide 122, 3, 6, 7 divide 426 is the GCD 4. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn a 5. Demonstration 6. Problems with Animation [Tversky et al.] Motion is fleeting and transient Cannot simultaneously attend to multiple motions People try to parse motion into events, actions andbehaviors We strive to infer causality and intention Anthropomorphizing: physical motion may causeconfusion or lead to incorrect conclusions Difficult to estimate paths and trajectories 7. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn aa=15, b=6a=15b=6 8. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn aa=9, b=6a=15b=6 9. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn aa=9, b=6a=3, b=6a=15b=6 10. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn aa=9, b=6a=3, b=6a=3, b=3a=15b=6 11. Euclids Algorithmdef gcd(a,b):while b != 0:if a > b:a = a-belse:b = b-areturn aa=9, b=6a=3, b=6a=3, b=3a=3, b=0a=15b=6 12. ? 13. Why Greatest Common Divisor?Fact 1Consider the answer rabr 14. Why Greatest Common Divisor?Fact 1Consider the answer rr divides babr 15. Why Greatest Common Divisor?Fact 1Consider the answer rr divides bConsider babr 16. Why Greatest Common Divisor?Fact 1Consider the answer rr divides bConsider babr 17. Why Greatest Common Divisor?Fact 1Consider the answer rr divides bConsider br divides a abr 18. Why Greatest Common Divisor?Fact 1Consider the answer rr divides bConsider br divides aTherefore, r divides a & babr 19. Why Greatest Common Divisor?Fact 1Consider the answer rr divides bConsider bb divides aTherefore, r divides a & bHence, r