McConville et al. (A-12) report the effects of chewing one piece of nicotine gum (containing 2 mg nicotine) on tic frequency in patients whose Tourette’s disorder was inadequately controlled by haloperidol. The following are the tic frequencies under four conditions:

Number of Tics During 30-Minute Period After End of Chewing Patient Baseline Gum Chewing 0–30 Minutes 30–60 Minutes 1 249 108 93 59 2 1095 593 600 861 3 83 27 32 61 4 569 363 342 312 5 368 141 167 180 6 326 134 144 158 7 324 126 312 260 8 95 41 63 71 9 413 365 282 321 10 332 293 525 455 Source: Data provided courtesy of Brian J. McConville, M. Harold Fogelson, Andrew B. Norman, William M. Klykylo, Pat Z. Manderscheid, Karen W.

Parker, and Paul R. Sanberg. “Nicotine Potentiation of Haloperidol in Reducing Tic Frequency in Tourette’s Disorder,” American Journal of Psychiatry, 148 (1991), 793–794. Copyright # 1991, American Psychiatric Association.

After eliminating patient effects, can we conclude that the mean number of tics differs among the four conditions? Let a ¼ :01.