Tilting in online poker. In poker, making bad decisions due to negative emotions is known as tilting. A study in the Journal of Gambling Studies (Mar. 2014) investigated the factors that affect the severity of tilting for online poker players. A survey of 214 online poker players produced data on the dependent variable, severity of tilting (y), measured on a 30-point scale (where higher values indicate a higher severity of tilting). Two independent variables measured were poker experience (x1, measured on a 30-point scale) and perceived effect of experience on tilting (x2, measured on a 28-point scale). The researchers fit the interaction model, E1y2 = b0 + b1x1 + b2x2 + b3x1x2. The results are shown below (p-values in parentheses).

b n 1 = .22 b n 2 = -.25 b n 3 = -.11 R2

= .18 F = 31.98 t = 5.75 t = -5.44 t = -5.61 16 .0012 16 .0012 16 .0012 16 .0012

a. Evaluate the overall adequacy of the model. Use a = .01 to test statistical significance.

b. The researchers hypothesize that the rate of change of severity of tilting (y) with perceived effect of experience on tilting (x2) depends on poker experience (x1). Do you agree? Test using a = .01.