Your subject matter expert knows everything about the topic. That's the problem.
Every instructional designer has lived this moment: the SME reviews your draft and adds three paragraphs to every slide. "This is really important - they need to know this." By the time you've incorporated all their feedback, your lean, focused module has become a textbook with a progress bar.
The SME isn't sabotaging your training. They're doing exactly what you asked them to do. The trap is in the question.
The Curse of Knowledge
Cognitive scientists call it the curse of knowledge. Once you know something deeply, you can't remember what it was like not to know it. Every detail feels essential because, for the expert, every detail connects to a web of understanding built over years.
A clinical nurse educator with fifteen years of experience sees a medication administration procedure as a network of interlocking decisions, contraindications, and edge cases. They can't separate "what a new nurse needs to know on day one" from "what I've learned matters over a career." To them, it's all one thing.
That's not a character flaw. It's a cognitive reality. And it's the instructional designer's job to navigate it, not fight it.
The SME's real value isn't content. It's judgement.
What the SME Actually Provides
The mistake most IDs make is treating the SME as the content source. Hand them a template, ask them to fill it in, build whatever they give you. This produces courses that are accurate, comprehensive, and completely ineffective.
The SME's real value isn't content. It's judgement. They know which mistakes kill people. They know which steps get skipped under pressure. They know what the textbook says versus what happens at 3am on a Sunday in a regional hospital with two nurses and a locum.
That knowledge is gold. But you have to mine it with the right questions.
Better Questions
Instead of "what does the learner need to know about this topic?" try:
"What's the most dangerous mistake a new person makes in their first month?" This gives you the scenario that matters. Build the training around preventing that mistake, not around the full body of knowledge.
"What do you wish someone had told you when you started?" This surfaces practical wisdom that never makes it into policy documents. The shortcuts, the workarounds, the unofficial rules that actually keep patients safe.
"If you could only teach them three things, what would they be?" This forces prioritisation. The SME will resist - they'll want to teach twelve things. Hold the line. Three things learned properly outperform twelve things skimmed.
"Where does this go wrong in practice?" This gives you the failure modes. Real scenarios emerge from real failures, not from best-practice flowcharts.
The Boundary Conversation
The hardest part of the SME relationship is saying no. Not to the person, but to the content.
"This is all accurate and important. But not all of it belongs in this course. Some of it belongs in a job aid. Some belongs in a mentor conversation. Some belongs in advanced training six months from now. This course needs to do one thing well: get a new person through their first week without making the mistakes that matter."
Most SMEs respect this when you frame it as a design decision, not a content cut. You're not saying their knowledge doesn't matter. You're saying the learner can't absorb it all at once, and the best way to honour that knowledge is to deliver it in the right dose at the right time.
The Real Job
The instructional designer's job isn't to capture everything the SME knows. It's to translate what the SME knows into what the learner can use. That translation is the craft. And it starts by asking better questions.
Nic