In an exploratory study such as this, one problem is defining what the "data" are - - the information we should collect. Also, what should have been done to minimize the effects of experimenter bias on the outcome of the study?

In the experiment related Stanfornd Prison, the fact that acted as a bias on the outcome of the study was that the researchers had to worry about aspects of sequirity instead of focusing on the research.

Explanation:

The rumor of the escape plot in the Stanford Prison, took a turn in the investigation, as the researches tried to take the matter in their hands,

This misslead the investigation, which involves observation more than taking part of the incident.

The investigator should have kept distance from the problem and let the prison superinendent solve the problem. This way the researches could have continued their exploratory study, without causing this bias to affect the investigation.