(1) Resources. What data do you want and need. Do you have the correct tools to get it (measuring tape, calipers, thermometers, colorimeters)?
(2) Training. Have you trained those who are collecting the data in how to use those resources and what the expectations are?
(3) Accountability. Does the team know that falsification of data can result in demotion, reassignment, or even disciplinary action?
Now, use the audit to engage those who are collecting the data. I used to have to check that certain paperwork (with measurements) was complete. I would look first for the form to be present and filled out. Then I began to ask the operations folks, "Can you show me how you got these values?" You learn a lot by watching them. If they struggle, then you may rightfully question the data, If they breeze through the measurements like "an old pro," the data is probably decent. That said, you should also understand how the data is generated so you know whether or not they are doing things correctly. I had an operator measure something, tell me what he got, and then I would measure it and see if we got the same answer.