Laura Conducted a Study to Determine Whether Her New "Puppet

Multiple Choice

Laura conducted a study to determine whether her new "puppet" therapy works better than the traditional "talking" therapy. After randomly assigning her own patients to either the "puppet" or "talking" group, Laura herself administered the therapy. This study is most obviously flawed due to the potential for

A) random variables.
B) experimenter bias.
C) the placebo effect.
D) participant expectations.