<p>In most situations it’s not very important, but in some cases it can be extremely important. </p>
<p>For example, if you’re interested in engineering, you need to find a school strong in engineering. However, if you’re interested in fields like history, biology, etc. it’s not as essential you find a strong program, although that’s a plus. You’re more trying to find schools with an overall fit.</p>
<p>Say you really like Brown. It’s physics department isn’t the greatest, but that’s ok. You need a solid foundation, and then you’re off to graduate school. However, the location, student body, etc. are more likely to make you happy than a school with a stronger physics program (like Caltech).</p>