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RESULTS—EXPERIMENT TWO 379

TABLE 7.17. Results of MANOVA, Experiment Two
MANOVA Effects Studied: 1—visibility, 2—day
Effect Wilks’ Lambda df 1 df 2 p-Level
1 0.839068 2 9 0.454033
2 0.479769 2 9 0.036698
12 0.631314 2 9 0.126213

• Independent variables:
1. Visibility, with 2 levels: visible and invisible.
2. Day (repeated measures), with 2 levels: day 1 and day 2.

The results are shown in Table 7.17. The p-level for the interaction effect is
bigger than the significance level (0.05), pointing to no significant interaction
effect. This means the result for one independent variable is not modified by
the other independent variable. The p-level for the visibility factor is also larger
than the significance level, so the null hypothesis should be accepted. In other
words, the overall human performance is not affected by the visibility factor. The
p-level for the day factor suggests a slight effect of the day (training) factor on
human performance. This reconciles with our knowing that the overall subjects’
performance was better on day 2 compared to day 1.
In order to see which indicator of human performance might be affected by
the day (training) factor, multiple univariate ANOVAs have been performed.
4. ANOVA was applied to the path-length-dependent variable in Experiment
Two. The variables involved are as follows:

• Dependent variables:
1. Path length.
• Independent variables:
1. Visibility, with two levels: visible and invisible.
2. Day (repeated measures), with two levels: day 1 and day 2.

The results are shown in Table 7.18. The p-levels for the main effects and
interaction effect are larger than the significance level 0.05. Each null hypothesis
for the main effects and interaction effect should hence be accepted. We conclude
that there are no significant effects of the visibility factor and day (training) factor,
and that these results do not change across the levels of the independent variables.
In other words, surprisingly, the visibility factor has no significant effect on the
subjects’ path length, and the day (training) effect has no significant effect on
the path length as well.