The Good Detective Asks Validity Questions

Validity Questions	Detective Questions
Construct Validity	What do the clues really mean? Is the suspect lying? Is the eyewitness accurate? Is the alibi solid? Is my gut feeling correct? Are the relatives wrong about other people's feelings and motives? Should I trust the polygraph results?
Internal Validity	Who/what really killed the victim? Do I have the right time of death? Was that bone broken long before death, at the time of death, or after death? Was it suicide, murder, accident, or death due to natural causes?
Statistical Validity	Is it just a coincidence that the suspect was in the vicinity of the murder? Are the similarities between these murders a coincidence or are we looking at a serial killer?

Validity Questions

Detective Questions

Construct Validity

What do the clues really mean?

Is the suspect lying?

Is the eyewitness accurate?

Is the alibi solid?

Is my gut feeling correct?

Are the relatives wrong about other people's feelings and motives?

Should I trust the polygraph results?

Internal Validity

Who/what really killed the victim?

Do I have the right time of death?
Was that bone broken long before death, at the time of death, or after death?
Was it suicide, murder, accident, or death due to natural causes?

Statistical Validity

Is it just a coincidence that the suspect was in the vicinity of the murder?

Are the similarities between these murders a coincidence or are we looking at a serial killer?

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