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Table 3 Final hierarchical model of factors affecting physical activity.

From: Relationship between objective measures of physical activity and weather: a longitudinal study

Factor Type I P-value* Type III P-value**
BMI 0.0273 0.0299
BMI2 0.0089 0.0136
Gender 0.5105 0.7973
Weekday <0.0001 <0.0001
Month <0.0001 0.0125
Weekday*Month <0.0001 0.0002
Days On Study 0.0123 0.8453
Days On Study2 0.0442 0.0348
Days On Study3 0.0169 0.0056
Total Rain <0.0001 <0.0001
Total Rain2 0.0019 0.0029
Mean Temperature 0.0002 0.0237
Total Snow 0.0541 0.0243
Total Snow2 0.4818 0.0394
Total Snow* Gender 0.0132 0.0129
BMI * Total Snow 0.5550 0.0227
BMI* Total Snow2 0.0375 0.0255
Maximum Wind Gust 0.0003 0.1455
Maximum Wind Gust2 0.0620 0.0211
BMI * MaximumWind Gust 0.9219 0.1089
BMI * MaximumWind Gust2 0.2046 0.0175
BMI 2 * MaximumWind Gust 0.6069 0.0825
BMI 2 * MaximumWind Gust2 0.0094 0.0112
Snow On Ground 0.0124 0.0124
  1. * The Type I p-value is associated with sequential tests of hypothesis, thus order of the factor in the above table is important (see example below).
  2. ** The Type III p-value is associated with "last in" tests of hypothesis (see example below).
  3. For example, consider the p-values for mean temperature. The Type I p-value measures the significance of the effect for mean temperature after adjusting for those effects in the table listed above mean temperature (BMI, Gender, Week, Month, Day on Study, Total Rain and the various interactions), but not those below mean temperature (Total Snow, Snow on Ground, and the various interactions). In contrast, the Type III p-value tests for the significance of the effect if it was the "last in" the model, i.e., adjusting for all factors in the table (BMI, Gender, Week, Month, Day on Study, Total Rain, Total Snow, Snow on Ground and the various interactions).