fieldwork motivation

When I interview people for entry level scientist jobs (i.e. involving fieldwork), it's hard to suss out how good a potential employee will be, unless of course there is some sort of obvious negative. Everybody is on their best behavior in an interview, and most technical stuff can be taught if someone's background is lacking.

I am looking for someone who is a "self-starter", which is unfortunately near-impossible to determine from entry-level interviews. What I mean is someone who can be taught the rudiments of what we need and who I can trust to go out and do that work independently, and who will a) ask if they have any questions and b) see what needs to be done and actually do it without constant nagging.

This isn't critical for officework because if somebody is lazy and playing solitaire all day, it will be discovered quickly based on the billable hours/work actually completed ratio. A manager (or anybody) can also drop by to hand off more work or see how things are going. When I'm in the field, however, there are consequences if work doesn't get done - there are equipment rentals to consider, idling drill rigs with antsy drillers, and we may have a strict client-dictated or regulatory time limit for doing the work. And there is always work to be done. Prep samples! Fill out health and safety paperwork! Catch up on your field logbook!

The independence thing is critical. If I'm managing a field site, I've got a million things of my own to do and I'm generally not working right next to other people - we're often spread out over a fairly large area. I physically cannot hover and make sure shit gets done. If someone seems bored, I have an extensive list of things to do, and if work gets slow, then that person can go help someone else who could use another hand. If you're doing soil sampling with a drill rig, you can always use another hand. But I need to hear that you've finished with whatever so I can give you something else to do.

I once had to supervise someone who was an anti-self starter. During a somewhat slow field day, I had told her to clean out the trailer and then go help someone else when she was done. Well, what she did was a half-assed sweeping job (this is bad because then I think, if you can't even sweep the goddamn floor properly, how can I trust you to watch a drill rig), then moseyed over to the person who could have used help and said, "are you ok with that?", got a sort of affirmative answer ("I guess I'm ok"), and then disappeared to take a nap. She was booted out in short order.