Latest / MBA Training AI / Right context, wrong assumption: what Morgan Stanley learned about prompting at scale
Transcript
- 0:00Welcome to the Leaders' Insights podcast.
- 0:07Today's episode, right context, wrong assumption, what Morgan Stanley learned about prompting
- 0:13at scale.
- 0:14Morgan Stanley gave its financial advisors an AI assistant, stuffed it with the firm's
- 0:19entire research library, and discovered something that should embarrass half the industry.
- 0:24More context made the answers worse.
- 0:26Explain that.
- 0:27The counterintuitive part everyone skips.
- 0:30Morgan Stanley wired their assistant to something like 100,000 internal research documents through
- 0:36OpenAI's models.
- 0:37And the early lesson wasn't, we need more data.
- 0:41It was, we're drowning the model.
- 0:43When you dump everything into the prompt, the prompt being the instructions and background
- 0:47you hand the model before it answers, it starts treating irrelevant paragraphs as if
- 0:52they matter.
- 0:53But that's the whole pitch, isn't it?
- 0:55Feed it your knowledge base and it gets smarter.
- 0:58You're telling me the pitch is wrong?
- 1:00The pitch is lazy.
- 1:01There's a well-documented failure mode researchers call, lost in the middle.
- 1:06Models pay attention to the start and end of a long context window and quietly ignore
- 1:11what's buried in the middle.
- 1:13So if the one document that answers the advisor's question is on page 40 of 60,
- 1:18the model may skim right past it.
- 1:20More pages doesn't mean more accuracy.
- 1:23It means more noise competing for the model's attention.
- 1:26So the fix is retrieval, right?
- 1:28Only pull the relevant documents.
- 1:30That's not new.
- 1:32Retrieval is the tool.
- 1:33That's RAG, Retrieval Augmented Generation, where you search your documents first and
- 1:38only feed the model the top matches.
- 1:41But Morgan Stanley's real insight was upstream of that.
- 1:46Retrieval only helps if you've decided what relevant actually means for that user in that
- 1:50moment.
- 1:52An advisor asking about a client's retirement allocation doesn't need last
- 1:56week's oil market commentary, even if the words overlap.
- 2:00The discipline isn't fetching context.
- 2:02It's ruthlessly deciding what to leave out.
- 2:05Give me a concrete example of that going wrong.
- 2:07Picture an advisor asks, what's our house view on municipal bonds for
- 2:12a high net worth client in California?
- 2:15A naive system retrieves 20 documents mentioning municipal bonds,
- 2:19including a technical piece on bond mechanics,
- 2:22a dated 2023 tax note, and a national overview.
- 2:26The model blends them and produces something generic and slightly stale.
- 2:31The right system knows the query has three constraints.
- 2:34The security type, the client tier, the state tax situation, and
- 2:38pulls only the current California specific guidance.
- 2:42Same model, completely different answer.
- 2:44This sounds like a lot of manual curation.
- 2:47Doesn't that defeat the point of automation?
- 2:49It shifts where the human effort goes.
- 2:52You're not answering questions manually.
- 2:54You're building the selection logic once.
- 2:56Morgan Stanley put real work into evaluation,
- 2:59having actual advisors grade responses before rollout.
- 3:03That grading is what tells you your retrieval is pulling garbage.
- 3:07Most teams skip it, ship the demo, and
- 3:09wonder why adoption dies in month two.
- 3:12Let's be honest about the numbers though.
- 3:14Morgan Stanley says advisors love it.
- 3:16That's the firm talking about its own product.
- 3:19How much do we trust that?
- 3:21Right to be skeptical.
- 3:22Vendor and first party numbers on AI adoption are almost always polished.
- 3:27What I trust more is the behavioral signal.
- 3:30They reported the assistant getting used across the vast majority of their
- 3:33advisor teams, and they kept investing in it rather than quietly shelving it.
- 3:38That's more telling than any satisfaction percentage.
- 3:41Firms kill tools that don't work.
- 3:44This one survived, which suggests the context selection discipline
- 3:48actually moved the needle.
- 3:49So for someone building this at a much smaller scale,
- 3:52a lawyer, a small consultancy, what's the transferable lesson?
- 3:57Stop thinking, how do I give the model everything I know?
- 4:01Start thinking, what are the three or
- 4:02four facts that actually determine the answer to this specific question?
- 4:07Structure your retrieval around those, not around keyword overlap.
- 4:11And test it against real questions from real users,
- 4:14not the tidy examples you invented.
- 4:16Give me the one thing to do Monday morning.
- 4:18Take your last ten prompts, and for each,
- 4:21delete half the context you fed the model, the least specific half.
- 4:25Run them again.
- 4:26If the answers hold or improve, that context was never helping.
- 4:31It was diluting.
- 4:32You'll learn more about what your model actually needs in 20 minutes than in
- 4:36a month of adding documents.
- 4:38That's a wrap.
- 4:39Fresh AI briefings drop daily at MBA-training.com.