... Difference1 0.40 0.37 -0 .032 0.37 0.14 -0 .233 0. 56 0.40 -0 . 16 4 0 .63 0.50 -0 .13Start of Impact5 0.33 0. 26 -0 .07 6 0.45 0.22 -0 .23Mean DifferenceBefore -0 .138After -0 .150Figure 6. 3 Results from ... 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., 19 86) . Sometimes information is ... Table 6. 2, and plotted on Figure 6. 3. The mean difference (impact - control) for times 1 to 4 before theaerial drop is -0 .138. The mean difference after the drop for times 5 and 6 is -0 .150,...