Problem 1

Images imbedded in random dot stereograms can be perceived by subjects through a stereo viewer. It is also possible to see the image by staring in between the two images and defocusing. An experiment was conducted to see if prior viewing of a sketch of the imbedded image affects the time it takes subjects to see the image. The data are at the bottom of this page, you should copy and paste the dataset directly into your R session. It should look like this: 
         Ftime       Group
         47.20001    NV
         21.99998    NV
         20.39999    NV
         19.70001    NV
         17.40000    NV
         14.70000    NV
           ...etc...
"NV" denotes the group with no visual preview of the image. "VV" denotes the group which got a visual preview. It will be easier to work with the data if you separate the data into two variables by group: 
NV <- FusionTime[FusionTime$Group == "NV",1]
VV <- FusionTime[FusionTime$Group == "VV",1]

We want to test the null hypothesis of no difference between the groups. We have several possible methods: the t-test, a t-test with log transformed data, a randomization test, and a bootstrap CI.

  1. Use all four procedures, and compare the conclusions each suggests.
  2. Make QQplots and Normal Quantile plots, and evaluate.
  3. Which methods seem appropriate for the data, which seem inappropriate, and why? 
 
"FusionTime" <- structure(list(Ftime =
c(47.20001, 21.99998, 20.39999, 19.70001, 17.4, 14.7, 13.39999, 13,
12.3, 12.20001, 10.3, 9.7, 9.7, 9.5, 9.1, 8.9, 8.9, 8.4, 8.09999, 7.9,
7.8, 6.9, 6.3, 6.1, 5.6, 4.7, 4.7, 4.3, 4.2, 3.9, 3.4, 3.1, 3.1, 2.7,
2.4, 2.3, 2.3, 2.1, 2.1, 2, 1.9, 1.7, 1.7, 19.70001, 16.19998, 15.9,
15.40002, 9.7, 8.9, 8.6, 8.6, 7.4, 6.3, 6.1, 6, 6, 5.9, 4.9, 4.6, 3.8,
3.6, 3.5, 3.3, 3.3, 2.9, 2.8, 2.7, 2.4, 2.3, 2, 1.8, 1.7, 1.7, 1.6,
1.4, 1.2, 1.1, 1), Group = structure(c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2),
.Label = c("NV", "VV"), class = "factor")), .Names = c("Ftime",
"Group"), class = "data.frame", row.names = c("1", "2", "3", "4", "5",
"6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17",
"18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28",
"29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39",
"40", "41", "42", "43", "44", "45", "46", "47", "48", "49", "50",
"51", "52", "53", "54", "55", "56", "57", "58", "59", "60", "61",
"62", "63", "64", "65", "66", "67", "68", "69", "70", "71", "72",
"73", "74", "75", "76", "77", "78"))