... called a control-treatment paired (CTP) design (Skalski and Robson, 1992, Chapter 6),or a before-after-control-impact-pairs (BACIP) design (Stewart-Oatenet al., 1 986 ). Sometimes information is ... = -0 .012 can be tested for significanceusing a two-sample t-test. This gives t = -0 .1 58 with 4 df, which is notat all significant (p = 0 .88 on a two-sided test). The conclusion musttherefore ... Table 6.2, and plotted on Figure6.3. The mean difference (impact - control) for times 1 to 4 before theaerial drop is -0 .1 38. The mean difference after the drop for times 5 and 6 is -0 .150, which...