I try to do this as much as possible in my current position, but I can't help but feel it does me a disservice when it comes time for a promotion.
It's viewed as a sign of weakness or incompetency.
I feel like those who never admit they don't know something are promoted up the chain. They don't trust you if you say "I don't know."
I do a lot video/motion graphics work. I'm often asked if I can accomplish something or finish by a certain deadline. Many times I can't give a definite answer, so I say I don't know. My bosses response was a sarcastic, "I like that confidence."
I find this to be the case for me, too. I'm a network tech at a non-technical (very non-technical) workplace. We're constantly dealing with new situations, new tech, a fast-changing media environment, and new requirements.
I'm honest when I don't know something, mainly because I don't want "my mouth to write checks that my ass can't cash." Claims of competence are going to be tested.
This doesn't impress the bosses. It kind of pisses them off.
This is a side effect of two things. First is a hierarchical kiss-up, kiss-ass culture -- this is in labor unions, so the organizational hierarchy is extremely important. Second is that they don't deal much with creating new IT services, but deal with people selling IT services or products. So the perception is that IT is magic, and it'll fix everything, if you just buy it. (LOLz)
There's also another reason, and it's that to a great extent, being able to get ahead or get things done within hierarchical organizations is about being a good salesperson. It's to bullshit enough to convince someone else with more power that something great is possible. It's useful to be a good salesperson.
Organizations value this quality in different quantities. An engineering consultancy, for example, would value having one person like this, to help make sales, but if they had too many it would be harmful - all the engineers would quit from being abused by salespeople making impossible promises, and there'd be no business at all.
A political consultancy, in contrast, would require this of almost every employee, except for people doing research or analysis. It would be a critical skill, because being able to bullshit many powerful people at once, in a coordinated way to achieve a specific result, is extremely difficult.
It's viewed as a sign of weakness or incompetency.
I feel like those who never admit they don't know something are promoted up the chain. They don't trust you if you say "I don't know."
I do a lot video/motion graphics work. I'm often asked if I can accomplish something or finish by a certain deadline. Many times I can't give a definite answer, so I say I don't know. My bosses response was a sarcastic, "I like that confidence."