Very informal. They provide you with a brief script, and, as long as you can read, you'll likely receive a call the moment a position becomes available. You'll likely be "interviewed" with several other candidates; in some cases, you'll be interviewed one-on-one.
If you're applying for the Surveyor position, DO NOT go off-script. Just read it verbatim, and inflect your voice as though you were speaking over the phone with a potential customer.
