What to Wear

I have a interview attire question I hope you can help with, should I wear a jacket to an interview? I have an in-person interview in a few weeks and have been told that the interview attire should be business casual. I understand the basics, my confusion is whether a jacket and/or tie is appropriate, I've come across conflicting information. I feel more comfortable in a jacket than without in professional situations, but I don't want to overdress. My gut instinct is that it is better to be more formal than less, but I don't have much real experience in the business world. Some details; I'm a PhD scientist, transitioning from academia to industry. The position has some managerial duties but is still mostly hands-on. The job is in biomedical manufacturing, with probably little, if any, interaction with people outside the company. Any insight you can give is appreciated.

My gut instinct is to go with the jacket, maybe a sport coat (note to my readers, from the name on the e-mail, I assume this person is male). Definitely a tie.

I've read that you should scout out the parking lot and see what people wear and wear that. I think you should scout out the parking lot, see what people wear and wear one step higher. (Unless it's a suit and tie sort of place, then you should not show up in a tux.) So, if they all come out in jeans, you go in a blue button down shirt and dockers. If they wear dockers and golf shirts, you wear dress pants and a button down shirt with a tie (conservative colors). If they wear the latter, you wear a suit.

I'll say, when I was hiring people to report to me (not recruiting, mind you), it really bothered me when people would show up under dressed--I felt like they didn't feel like the interview was important.

My opinion may be old school though, so perhaps my readers can comment and make suggestions.