A researcher conducted a study to examine the effect of the number of tasks on performance accuracy. Participants were randomly assigned one or three tasks to perform simultaneously. Accuracy on the...

A researcher conducted a study to examine the effect of the number of tasks on performance accuracy. Participants were randomly assigned one or three tasks to perform simultaneously. Accuracy on the target task (the task performed by both groups) was measured for both groups. Accuracy was found to be similar for the two groups.

Describe two possible sources of bias in this study and explain how each source of bias could have caused the results reported.