When you go to your render settings, and click on artificial (or sun+artificial) it will give you the option to check which lights are turned on or not. Also changing the time settings for your render will reduce this somewhat...if its darker outside you will get more reflections inside.

Thanks for your reply. What I'm wondering about, though, is what's causing the dome shaped reflection under each ceiling light in the windows. I'd like to get rid of it but still have the lights turned on. why would something show up in the reflection that isn't visible on the fixture itself?

if you edit the light fitting itself, you will see what kind of "diffusion" is set on your light fitting.
You probably need to just play around with this a bit, maybe also the lux value of your light might be messing with it.
I can say Im only starting to mess around with lighting in renders and its a freaking PITA so many little nuances but to me, that ball resembles the diffusion type which will be visible in the light family itself - and it will be those little spots hidden in the ceiling, not the long fluro lights.

I would have to look in the actual light family itself to see whats going on, check how that family is made it might be a piece of junk



also you might find that link useful