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Report of the Committee on Ballistic Acoustics (1982) / Chapter Skim
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APPENDIX A CRITICISM OF PROBABILITY CALCULATIONS
Pages 35-40

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From page 35...
... Please APPENDIX A 35 APPENDIX A CRITICISM OF PROBABILITY CALCULATIONS A-L. CRITICISM OF BRSW PROBABILITIES 0.88, 0.88, 0.50, AND 0.75 This criticism refers to the calculation by BRSW of probabilities of 0.88, 0.88, 0.50, and 0.75 for the identification of 4 impulse patterns of the DPD tapes as representing four shots.
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From page 36...
... We would suggest that a conservative estimate of this probability based on the BRSW reasoning would be 2/9. Instead, BRSW apparently misinterpreted their own words, reading "equally likely" to mean that the probability of a false alarm for each detection is 1/2, an interpretation consistent with the somewhat ambiguous language but not with the reasoning.
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From page 37...
... In that case the significance of the layout is considerably reduced and one may question the conclusion on page 64 of the BRSW report that "the motorcycle was moving through Dealey Plaza and did, in fact, detect the sounds of gunfire." (To be specific, a two by two table with entries 1,3,4,0 yields a significance value P=0.07, rather than the P<0.01 claimed by BRSW.) use the print version of this publication as the authoritative version for attribution.
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From page 38...
... The adjustment used by BRSW/WA is somewhat ad hoc, depends mainly on adjusting three of these parameters use the print version of this publication as the authoritative version for attribution.
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From page 39...
... . For the BRSW hypergeometric probability calculations to be appropriate, it is necessary to use use the print version of this publication as the authoritative version for attribution.
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From page 40...
... These might invoke the nature of the bursts of noise prevalent during the period under study and a consideration of other possible non-Poisson distributions. use the print version of this publication as the authoritative version for attribution.
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Key Terms

  • grassy knoll
  • print version
  • false alarms
  • impulse patterns
  • conjectured shot

  • alternative hypotheses
  • initial position
  • dpd tapes
  • hypergeometric probability
  • remaining nine

  • probability calculations
  • contingency table
  • initial positions
  • false alarm
  • brsw apparently

  • brsw calculations
  • brsw hypergeometric
  • msec total
  • calculated probabilities
  • impulse locations

  • requires review
  • microphone detected
  • calculations claim
  • brsw observe
  • brsw certainty

  • table analysis
  • nine remaining
  • dpd tape
  • using prior
  • knoll fails


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