How to Underwriters Automate the Appraisal Process

[John Whitridge]

Hi BP, I am a real estate investor in Philadelphia I've been thinking about some ways to get more involved in the market, one of which was getting more familiar with the data that supports house sales.  A few friends of mine and I were talking and we realized that a lot of the prices we talk about are based on a "hunch" and not necessarily data. 

I'm curious if underwriters have any algorithms or programs that take care of this automatically based on a few inputs or if they largely pull comps manually?  Another way of asking is: is underwriting an exact science or is there some level of uniqueness that each underwriter brings to the table? 

Thanks!