An investigator wishes to conduct a test of the effect ofalcohol consumption on the performance of automobile drivers,possibly to gain more information about the legal maximum for DUIarrests. Before the driving test, subjects drink a glass of orangejuice laced with controlled amounts of vodka. Their performance ismeasured by the number of errors on a driving simulator. Fivesubjects are randomly assigned to each of five groups receivingdifferent amounts of vodka (either 0, 1, 2, 4 or 6 ounces), and thefollowing results were obtained: DRIVING ERRORS AS A FUNCTION OFALCOHOL CONSUMPTION (OUNCES)
ZERO ONE TWO FOUR SIX
1 4 6 15 20
1 3 1 6 25
3 1 2 9 10
6 7 10 17 10
4 5 7 9 9
Total: 15 20 26 56 74
SumX= G= 191 SumX2 = 2371
A) Using SPSS, conduct an ANOVA, including post hoctests if necessary.
B) Using either h2 or Coen’s d, calculate effect size. What kindof effect does this indicate?
C) What, in plain English, does all this mean?
