. Author manuscript; available in PMC: 2019 Jun 1.

Published in final edited form as: Psychol Addict Behav. 2018 May 17;32(4):426–433. doi: 10.1037/adb0000370

Table 2.

Comparing Estimated and Actual Weights of Marijuana Used in the Quantity Estimation Task

	Actual Weight (in grams)	Estimated Weight (in grams)	Absolute Difference (in grams)	n	r (p-value)	t (p-value)	Cohen’s d	% Estimated Weight/ Actual Weight
Flower-Combined	.400	.583	.182	104	.661 (<.001)	5.198 (<.001)	.557	145.75%
Flower-Bowl	.246	.414	.168	63	.406 (=.001)	5.944 (<.001)	.823	168.29%
Flower-Joint	.583	.800	.217	41	.618 (<.001)	2.866 (=.007)	.569	137.22%
Concentrate	.076	.162	.086	59	.273 (=.036)	4.177 (<.001)	.621	213.16%