Case studies are meant to satisfy every professional's voyeuristic impulse—each an inspirational opportunity to observe the cloaked-in-secrecy process that took a company from challenge to success.

So what's not to like? According to Rohit Bhargava, writing at the Influential Marketing Blog, case studies are burdened with many inherent weaknesses. And that means they're not always as useful as they seem.

So when you create your next case study, or sit down to read one, consider the following four insights.

1. Accurate self-assessment is tricky

We all have blind spots (and a few not-so-blind spots) when we write about our own efforts. Those blind spots will naturally skew our viewpoints because we're prone to omit relevant details we don't see—and might feel the temptation to gloss over a few that we do. An objective critique from a trusted colleague might help to identify problematic perspectives.

2. Accurate secondhand assessment is also tricky

When someone without direct knowledge of the initiative writes the case study, readers rely on her skills to ask the right questions and get the right answers. Though accurate secondhand assessment can be achieved (just look at the demonstrated talents of former MarketingProfs writer Kimberly Smith, accurate reportage requires savvy and skill.

3. Failure is often more instructive

Think about the most important lessons you've learned in your life. If you're anything like me, you gain the most significant insights when something goes horribly wrong. "We need to see more case studies of what didn't work so we can learn from failure as well as success," argues Bhargava.

4. Case studies tend to be light on behavioral insights

The typical case study's narrative presents the challenge, explains how your team devised and implemented an action plan, and reports on pleasingly spectacular results. But, says Bhargava, though case studies note that customers did respond to a message or approach, they rarely examine why.