Re: Are surveys and interviews considered as an objective measurement?
I can say only can be.

Being objective would mean a checklist of structured evaluation(s).
I am sure that serveys & interviews have objectives defined, but not always, and clearly not completely always.
Will these objective be efectively used is another question.
In some cases serveys might be the only validation data.
going

Is any audit completely objective?
Is a ploiceman totaly objective?
(Red sports cars, beautiful lady, ugly fat guy, old dinged-up pickup)