Tomorrow, I have to attend an orientation for a selective summer science program. In an email, the coordinators said “dress is casual”, however I have no idea what that means. As a teenage girl, “casual” can mean a whole lot of different things (just look at school hallways - one person is in their pajamas and the next looks like a fashion model). Are shorts ok? How should I dress? At the interviews for the program everyone was in a pantsuit/formal attire. Any tips? Agh fashion is confusing?
Sincerely,
Fashion-ly challenged student
My opinion: shorts would be fine, with a shirt of some sort; could make it khakis with a nicer shirt if you’re worried. I’d personally also make sure I wasn’t showing any butt or boob beyond what is tasteful. 
If you wont die of overheating I would recommend long, darker jeans just ot be on the safe side but idk.
Nothing torn or too revealing. No tee shirts.
I think this means neat and comfortable but not sloppy. Agree with @TomSrOfBoston – not revealing. A polo short with (not too short or tight) shorts would be fine. A sundress would be fine (if your boobs and butt are covered.) After the program starts, you’ll know what the daily standard is. As a rule of thumb, it’s generally better in situations like this to err on the side of being overdressed. You already know that you don’t need to be formal or “business-y”, so pitch it at the level just below that.