Page 330 - Solid Waste Analysis and Minimization a Systems Approach

308 MODEL VALIDATION AND CASE STUDY APPLICATION

TABLE 19.2 MODEL VALIDATION TESTS (HYPOTHESIS TESTS* TO EXAMINE IF
SIGNIFICANT DIFFERENCES EXIST BETWEEN THE MODELS DEVELOPED FROM
†
SURVEY DATA VERSUS ADDITIONAL DATA COLLECTED ) (CONTINUED)
DEVELOPED
DEVELOPED MODEL
MODEL COEFFICIENT
COEFFICIENT USING
WASTE SIGNIFICANT USING ADDITIONAL CRITICAL
GROUP VARIABLE SURVEY DATA DATA T VALUE †† VALUE P VALUE
EDU Employees 0.25 0.28 0.270 2.776 0.801

ELM Employees 2.29 2.58 0.948 2.110 0.349
Disposal cost −0.83 −0.78 −0.121 2.110 0.904

ISO 14001 −53.31 −55.25 −0.136 2.110 0.892
ARG Employees 1.29 1.38 1.020 2.179 0.326

FDM Employees 7.19 7.48 0.830 2.228 0.426
Disposal cost −5.17 −5.08 −0.410 2.228 0.691

ISO 14001 −183.50 −173.81 0.730 2.228 0.482
FDS Employees 2.71 2.58 0.840 2.306 0.425

HTL Employees 2.01 2.18 0.980 2.447 0.365
MED Employees 0.98 0.94 1.070 2.365 0.32

MLM Employees 8.43 8.54 0.270 2.776 0.801
Disposal cost −7.51 −7.21 −0.460 2.776 0.669

ISO 14001 −214.90 −211.05 −0.730 2.776 0.506

REC Employees 1.87 1.73 0.380 2.447 0.717
RST Employees 5.91 6.05 0.810 2.306 0.441
RTL Employees 0.78 0.84 0.180 2.12 0.859

TRM Employees 2.97 2.81 0.640 3.182 0.568

Disposal cost 1.73 −1.64 −0.510 3.182 0.645
ISO 14001 −56.22 −58.92 −0.430 3.182 0.696

WDM Employees 17.40 15.81 0.790 2.776 0.474
Disposal cost −7.76 −7.51 −0.810 2.776 0.463

ISO 14001 −217.59 −207.73 −1.080 2.773 0.341

*Hypothesis tests conducted at the 95 percent confidence level with H : regression coefficients are equal and
0
H : regression coefficients are not equal for survey data versus Greene County data for each waste group.
1
† Waste generation data was available for 16 of the 21 waste groups from the Greene County Solid Waste
District (external data source).
†† All hypothesis tests resulted in a “do not reject H , the null hypothesis.”
0