In too many businesses, challenging even the worst idea can quickly put you on the hot seat. It’s a shame because companies should strive for a culture of candor — a workplace where employees aren’t afraid to play devil’s advocate and thoroughly examine new ideas and proposals.

“Almost everyone who reads this can relate to those situations where a manager announces their latest and greatest idea and everyone in the room nods their heads while silently thinking, ‘This is absolutely crazy,’” says Dana Brownlee, a corporate-training consultant and founder of Professionalism Matters (www.professionalismmatters.com). “We all joke about it, but this phenomenon can lead to disastrous consequences — products that go to market and fail because they weren’t properly vetted or projects that consume tons of time and money but never should’ve happened in the first place.

“It’s very rare to have a workplace climate where people feel comfortable about raising their hand and expressing concerns,” she continues. “It goes against every political instinct we have in our DNA.”

The telltale signs of a culture of fear are obvious, Brownlee says. You know the drill: There’s the “meeting after the meeting,” where employees who smile and nod their approval as the boss announces another doozy of an idea then gather in a break room and whisper about the ridiculous proposal. She says she’s even seen employees sitting in on conference calls use instant messaging to tell colleagues about a particularly wild idea being proposed.

“Or if you’re attending a large, all-hands meeting and the president of the company asks if anyone has questions about a new proposal, and no one raises their hand,” she adds. “If you have that many people in a room and you have zero questions, you’re working in an organization with low trust.” Worse yet, it convinces executives that bad ideas are viable. “They’re thinking, ‘Well, that went well, didn’t it?’” she says.

The business world is rife with evidence of “great ideas” that became epic fails. Does anyone remember New Coke? Betamax video format? (There’s a good reason you may not.) The Apple Newton personal data assistant? The Microsoft Zune, which was supposed to compete with the iPod? (It didn’t.) Or how about high-definition DVDs? (Blu-ray technology elbowed it aside.) The list goes on and on.

There are many reasons why employees won’t tell the boss he or she has an ugly dog, so to speak. High on the list: concern about retribution. Or they’re afraid they’ll be the only one to say something — even if they believe others share their skepticism. Or perhaps they lack the confidence or conviction to express an opinion, fearing it’s without merit.

On the flip side of the coin, business leaders often don’t understand how the power of hierarchy dampens candor. They just can’t fathom that people wouldn’t be honest with them. Brownlee recalls one instance where she told a woman who was second-in-command at a major company that employees feared being honest with her. “She looked at me like I had five heads. Sometimes senior executives live in a totally different reality.”

Of course, everyone comes up with a loser of an idea every so often. But the problem is that bosses have the power to make them a reality, as opposed to those at the lower end of the food chain. “So there’s a responsibility at both ends,” she notes. “Good leaders rely on staffs to be honest with them, so it’s unfortunate when people don’t speak up.”

Brownlee points out that it’s not what you say when raising concerns, it’s how you say it. In other words, when you’re talking to your manager, don’t say the idea is terrible and ask what he or she was smoking. “Instead, tell them it’s a good idea, but the only concern I have is x, y and z,” she suggests. “Or say, ‘I know this is your baby, and I fully support it, but I’ve heard some rumblings that could raise red flags. Do you want me to bring those up to you or keep it to myself?’ It’s always good to ask for permission upfront, and phrasing concerns as a question is much less threatening.”

On a broader level, businesses need to let employees know that candor is a corporate value to be prized, not punished. They should encourage employees to play devil’s advocate because it’s better than having a customer discover a problem that should have been solved in-house.

There are a variety of techniques to make employees feel more comfortable with candor. Brownlee says one manager she’s worked with puts $5 in a jar every time one of his reports pushes back on a new idea. He then uses the money to fund a once-a-month pizza party.

When Brownlee was a team leader and project manager for a major telecommunications company, she would put an index card on every chair in a room where she was announcing a new initiative. On the card was written, ‘My biggest concern about this project’s success is ___________.’ When she’d finish the presentation, she’d ask employee to anonymously fill in the blank and drop the card in a bag as they left the room. “This technique gave me tons of candid feedback,” she explains.

It takes time to change a culture, and it’s the little things that matter, Brownlee says. “There’s no real formula for changing it,” she notes. “It takes a lot of role modeling by managers. It’s the small things you do at the granular level that change the paradigms.”