I recently attended an interview for a senior position in a large accounting company. When I met up with my sister for dinner later that day, she commented on my appearance, saying that I wasn’t suitably dressed for such interviews. Although I had thought I was well groomed, wearing a knee-length dress and cardigan, she seemed to think that only very formal wear is acceptable in interviews. How much do the details in an outfit affect first impressions in a high-calibre interview? Do I have to go out and buy some wear suits? Or would a formal dress be acceptable?