Table 4 Chi-square goodness of fit test whether the proportion of correct or incorrect fiber tests is significantly different than 0.5 (alpha = 0.05, DF = 1, critical value = 3.84, N = number of fibers tested across all individuals performing the test). Fraction of correct fibers tested (fcorrect) is also tabulated
Material | HNT 1 | HNT 2 | ||||||
|---|---|---|---|---|---|---|---|---|
fcorrect | \(\boldsymbol\chi^{\mathbf2}\) | p | N | fcorrect | \(\boldsymbol\chi^{\mathbf2}\) | p | N | |
Nylon | 0.94 | 12.25 | 0.0005 | 16 | 1.00 | 11.00 | 0.0009 | 11 |
Polyester | 0.76 | 5.76 | 0.02 | 21 | 0.79 | 4.57 | 0.03 | 14 |
Acrylic | 0.81 | 8.05 | 0.005 | 21 | 0.42 | 0.33 | 0.56 | 12 |
Cigarette filter | 0.64 | 1.64 | 0.20 | 22 | 0.57 | 0.29 | 0.59 | 14 |
Cigarette filter-digested | 0.22 | 7.35 | 0.007 | 23 | 0.55 | 0.09 | 0.76 | 11 |
Polypropylene | NA | 1.00 | 15.00 | 0.0001 | 15 | |||
Spartina grass (dead) | 0.81 | 6.25 | 0.01 | 16 | NA | |||
Cotton | 0.50 | 0.00 | 1.00 | 18 | 0.82 | 7.12 | 0.008 | 17 |
Viscose | 0.65 | 2.13 | 0.14 | 23 | 1.00 | 17.00 | 0.0001 | 17 |
Silk | 0.76 | 4.76 | 0.03 | 17 | 1.00 | 12.00 | 0.0005 | 12 |