= Practice Problem - Answers/Results =

== Effect of Deafening on Adult Song Structure ==

 * First, calculate the group means/SEM so you can get a general feel for the data.

 || Animal ID	|| Predeaf	|| Deaf7	|| Deaf14	|| Deaf21 ||	Deaf28	|| Deaf35 ||
 || r54a	|| 79.0	|| 73.9	|| 73.0	|| 71.1	|| 66.5	|| 62.1 ||
 || r55a	|| 99.5	|| 94.2	|| 89.7	|| 83.6	|| 72.6	|| 65.2 ||
 || r58a	|| 92.3	|| 92.7	|| 93.3	|| 87.7	|| 79.7	|| 66.2 ||
 || r62a	|| 90.3	|| 91.6	|| 92.8	|| 90.1	|| 85.9	|| 80.6 ||
 || r64a	|| 96.4	|| 90.8	|| 87.8	|| 82.1	|| 75.8	|| 61.9 ||
 || r78a	|| 87.2	|| 87.0	|| 85.0	|| 80.1	|| 80.2	|| 80.0 ||
 || r77a	|| 82.0	|| 81.0	|| 75.0	|| 78.0	|| 76.7	|| 76.2 ||
 || mean	|| 89.5	|| 87.3	|| 85.2	|| 81.8	|| 76.8	|| 70.3 ||
 || SEM	 || 2.8	|| 2.8	|| 3.1	|| 2.4	|| 2.3	|| 3.1 ||

 * Next, enter the data into Prism and run the appropriate analysis.  
 . NOTE: You should use a repeated ANOVA  (independent ANOVA yields p=.0002; predeaf vs d21 ns)

 {{attachment:practice2-figure1.png}}

 * Finally, construct a summary statement that accurately reflects the results obtained. For example:

  ''Repeated measures ANOVA revealed a significant main effect of deafening on song acoustic structure (F (5,30) = 14.39, p<.0001.  Similarity scores were significantly lower by 21 days after deafening than those before deafening (t=2.875, p<.05), having declined by an average of 8 + 2%.   Songs continued to degrade thereafter, and by  d35 the similarity scores were 21 + 5% lower than before deafening (t=7.16, p<.001).''

 * Note that in the text above, we provide a supplemental measure(% song degradation) to help the reader appreciate the effect of deafening.  Check the formula used in the data set below to see how we calculated % degradation.  


  || % decline	|| Predeaf	|| Deaf7	|| Deaf14	|| Deaf21	|| Deaf28	|| Deaf35 ||
  || r54a	|| 0%	|| 6%	|| 8%	|| 10%	|| 16%	|| 21% ||
  || r55a	|| 0%	|| 5%	|| 10%	|| 16%	|| 27%	|| 34% ||
  || r58a	|| 0%	|| 0%	|| -1%	|| 5%	|| 14%	|| 28% ||
  || r62a	|| 0%	|| -1%	|| -3%	|| 0%	|| 5%	|| 11% ||
  || r64a	|| 0%	|| 6%	|| 9%	|| 15%	|| 21%	|| 36% ||
  || r78a	|| 0%	|| 0%	|| 3%	|| 8%	|| 8%	|| 8%  ||
  || r77a	|| 0%	|| 1%	|| 9%	|| 5%	|| 6%	|| 7%  ||
  || mean	|| 0%	|| 2%	|| 5%	|| 8%	|| 14%	|| 21% ||
  || SEM	|| 0%	|| 1%	|| 2%	|| 2%	|| 3%	|| 5%  ||