In financial accounting a public company (say General Motors) will create aggregated financial statistics that they publish in their quarterly reports.
They hire an accounting firm (say Deloitte) in to check their work by looking at some sample of their documentation. This is a lot like Deming-style quality control; they look at some fraction of the checks that came from car dealers, or that were cut to parts suppliers and see that the story makes sense.
In fields like insurance where fraud is particularly dangerous they do things like look to see if there is a real person for some of the policies, etc.
I would look to the same model for other kinds of accounting too.
For instance, if the company said that 42% of its employees are women they could let a third party look at a sample of 1000 employees that the third party chooses, going so far as letting the third party see employement records filed with the state, contact those employees, etc.
Like a public opinion poll it is not an exact answer, maybe they will find 40% or 44% of the employees are women, which is close enough.
That is just one trick in the toolbox that accountants have, sometimes they will see a bunch of deposits with round numbers ($7700) and then you get one for $345.34 and that is the one they ask you about.
So that's the subject you should be looking up, the kind of people you should be talking to.
