As an Architect, how can you fairly judge technology on which you have never or seldomaly worked

I aspire to become a Software Architect. I have question in mind which bothers me a lot.
As a Software Architect, when you have to judge between two or more technology solutions, how can one decide which one is better?
Suppose one is more inclined towards Java technologies because of past experience in that and haven't worked much on Microsoft technologies, how will he/she fairly judge between two?
Wouldn't he/she always try to do that in Java first? How to be neutral in these kind of situations and collect proper knowledge about both technologies first, to find the solution?

Thanks!

In my view,

-- You will have to look at what your developers are skilled in to get the job done. If you have a pretty strong Java team then go with Java.
-- You will have to look at ways in which you can leverage existing investment and infrastructure.
-- You will have to look at the licensing arrangements, support arrangements and overall cost.
-- You will have to make the build versus buy decision.
-- Come up with the alternatives and pros and cons for each alternative and then the reasons for your decision. You will also have to communicate this to the relevant stakeholders and get their approval.
-- A proof of concept is often required.

Would like to hear from Dave.

Hi Bhagwant,

I agree with Arulk's reply.

A few other things that should be considered are:
-- what is the strategic direction of the company/division/department?
-- what are others in the industry doing (look at things like tech radars)?
-- what are the operational costs?
-- has anyone else in the company already solved this problem, if so, how?

Good question!