Effective methods of data collection related to a criminal justice organization.

Describe one or two of the most effective methods of data collection related to a criminal justice organization.
Discuss the importance of collecting unbiased data for research.
What type of evidence or facts would you use when making a decision?
Respond to at least two of your peers, addressing the following:

Identify some possible benefits to their suggested data collection methods.
Identify some possible drawbacks to their suggested data collection methods.