Page 311 10.6. Interrogating Causal Claims with the Four Validities Which of the following questions are applicable to interrogating internal validity? Applicable Did the study ensure there were no variables that systematically varied with the independent variable? Press Space to open Did the study use random sampling? Press Space to open Did the study use random assignment? Press Space to open Did the study have zero in the 95% CI? Press Space to open Did the study counterbalance the order of conditions? Press Space to open Not Applicable