I have an interview for a PhD position (engineering) at a Central German University. I am not sure what to wear (formal wear for woman). Since certain countries are very particular about what you wear to an interview, I want to make sure that I don't look out of place. Any suggestion about formal wear for woman would be appreciated.
I think this is highly field dependent, but in general overdressed is better than underdressed. In fields close to mine (math, computer science) things are quite relaxed, so no one would expect a (skirt) suit (although this would be ok) and nice trousers (usually including jeans) and shirt are most probably ok. Ragged jeans and t-shirt may not always work, though. Avoid wearing something revealing.
I can tell you that as a female grad student in Sweden in mathematics, I wore a nice pair of jeans, a (ironed!) white shirt, ballet flats, and discreet jewelry (small gold studs and a thin gold bracelet) for my interview. I got the position. I did not stand out in any way from the other interviewees or professors.
In general, I would perhaps switch the jeans for a pair of slacks, and if it's cold outside, switch the ballet flats for a pair of (freshly polished!) boots. Then you would blend, but be on the nicer side, in any northern European science department I've ever visited.
Scientific academia in Germany is very informal these days; dress codes barely exist at all, and there is no expectation to dress up, or to dress gender specifically. This includes engineering.
In general, for interviews, the rule “better overdressed than underdressed” applies of course. However, in my experience it’s even more important that you feel comfortable. I’ve been in a very similar situation to yours and felt uncomfortably overdressed, which made me nervous and certainly didn’t help my chances in the interview.
So: if you feel comfortable dressing formally, do that. If not, I’d suggest dressing slightly less formally rather than facing discomfort. At any rate, as others have noted, I’d avoid a too casual/careless clothing style, as for any interview.
Here are two tips:
1) Look at the current faculty's (or PhD students') departmental headshots and webpages online. If most people dress in a suit or blazer for the photos, then I would suggest you dress in that way for the interview.
2) If you wear a pantsuit or slacks/blazer, try to wear a shirt underneath that would also be perceived as appropriate without the jacket (i.e. no sleeveless shirts). Then you will be able to remove the jacket and leave it with your luggage if you perceive yourself to be overdressed.
I know these don't precisely address the German context, but I thought the ideas might be helpful to the OP.
You can't go wrong with a pants suit. That's why women politicians favor them. You don't look overdressed in a pants suit; yet they also fit when the men in the group are wearing a suit and tie. You would only look overdressed in a pants suit if you were attending an informal outdoor party! And even there, you'd be okay, by just taking off the jacket.
The top worn under the jacket should be a simple knit top (not form-fitting as you might wear to a nightclub, but not baggy like a T-shirt you'd wear for sports). It can be long sleeved in the winter if you wish. Avoid anything sleeveless. Make sure that even when bending forward, no under garments or straps are visible.
Wear comfortable shoes in case there's a lot of walking to do. (Thank you to Robokaren for this advice on another clothing question.) Don't wear perfume or scented personal hygiene products (e.g. deodorant). If your shampoo or conditioner has a subtle perfume, that is okay, however.
Note, if you are a person who likes wearing a skirt instead of slacks, that's fine too.
Blouses are a bit unusual these days, but you could wear one if that's your style. However, please avoid ruffles, lace, garish colors, or partial transparency.
Don't forget to let your personal style come through. If you are someone who enjoys wearing a warm Scandinavian style sweater in the colder months, go for it! As long as the sweater is still in very good repair (no pilling or thread pulls). If you wear a pullover, make sure you have a formal sort of top on underneath, in case you find yourself in an overheated room and need to take off a layer.
To play it safe, do not wear jeans. Once you know the group better, you'll know whether jeans are okay or not.
Make sure your winter coat is warm, clean and tidy.
If the weather is bad, do not hesitate to wear sturdy boots that will keep you warm and dry.
EDIT: In Germany
Women also dress conservatively, in dark suits and white blouses or conservative dresses. This form of dress is observed even in comparatively warm weather. Do not remove your jacket or tie before your German colleague does so.
I would dress professionally. You are interviewing for a job at a university, not a tech startup. So for a woman I would wear something more conservative - perhaps a nice skirt and blouse? However, the important thing is to be comfortable! That's how you'll do your best.
The dress code in engineering in Germany varies widely. I know one institute where the professor forces his PhD-students to show up in suits every single day. At the other end of the spectrum are institutes where even professors just wear normal clothes all the time, even for interviews with candidates.
I would recommend to look at the homepage of the institute you're applying to and check out the pictures of your potential supervisor and his/her PhD-students. If all of the students are wearing suits on their pictures, wearing something similar for the interview is definitely a must. If even your potential supervisor wears something very casual, you should be fine with a clean t-shirt and jeans. For the cases in between, I would recommend a blouse combined with a skirt or slacks. (I would even recommend this for the casual supervisor, just to be on the save side. You will never appear as overdressed if you dress like this.)
First, as said by others, do as "they" do, whoever they are. We don't really know what's en vogue at your place.
This triviality aside, I would strongly suggest for you to look past this interview and, along with a possible new job, decide on which style you are seeing yourself sporting in the future. Do you wish to come accros as a hands-on "techie"? Do you see yourself in a management position in 5 years?
Put yourself in that mindset, and wear appropriate clothes. I know you are asking which the appropriate clothes are, but I suggest that it is most important four you to decide which image you want to portrait. Google "woman business clothing" and switch to the image search, everything you see there will be appropriate for about any professional setting in Germany, from universities to companies.
Looking at said google image result, not being a woman myself, I believe the most important choice you have to make is whether your clothes end above or below the knee, or at the shoes. That is a personal choice for you, as in Germany, most everything will be accepted (with a certain minimum height which should be pretty obvious). And it will also depend on your character a bit, and what makes you comfortable.
Being comfortable is of the utmost importance, so if in doubt, do as you really want to!