Table 3.

Test statistics from analyses comparing each visual aid with the no visual condition on accuracy measures.

Accuracy Measure	Pie chart vs. No visual	Bar chart vs. No visual	Table vs. No visual	Pictograph vs. No visual
Print Ad
Absolute frequency	0.80, P = 0.42	2.95, P = 0.003	2.74, P = 0.006	−0.01, P = 0.92
Percent	0.96, P = 0.34	3.40, P = 0.001	2.81, P = 0.005	0.36, P = 0.72
Relative frequency	2.07, P = 0.04	2.93, P = 0.003	3.11, P = 0.002	1.70, P = 0.09
Placebo	0.91, P = 0.36	2.85, P = 0.004	4.23, P < 0.001	2.38, P = 0.02
Television Ad
Absolute frequency	5.45, P < 0.001	7.57, P < 0.001	4.68, P < 0.001	3.99, P < 0.001
Percent	5.01, P < 0.001	7.26, P < 0.001	4.70, P < 0.001	3.69, P < 0.001
Relative frequency	1.91, P = 0.06	2.81, P = 0.005	−0.01, P = 0.99	−0.13, P = 0.90
Placebo	5.66, P < 0.001	7.26, P < 0.001	6.57, P < 0.001	5.73, P < 0.001

Note: Accuracy (absolute frequency, percentage, relative frequency, and placebo) was measured as the percentage who reported the correct quantitative efficacy information. Bonferroni-adjusted significance was defined as P < 0.005. Print condition t-tests had 1,308 degrees of freedom. Television condition t-tests had 1,194 degrees of freedom.