Is Google Analytics Accurate?

Question

My records show a particular page of my web site was visited 609 times between July 2 and November 15.

Google Analytics reports only 238 page views during that time.

Answer 1

Justin's answer is very good. I would just add this as a comment but I'm lacking powerpoints :P

One thing to keep in mind, too, when comparing analytics systems, is that there's always some discrepancy to be expected:

The methodology of page tagging with JavaScript in order to collect visit data has now been well established over the past 8 years or so. Given a best practice deployment of Google Analytics, Nielsen SiteCensus or Yahoo Web Analytics, high level metrics remain comparable. That is, can be expected to lie between 10-20% of each other.[ link ]