Anchoring bias means the first number a client hears becomes their reference point for every number that follows, regardless of the caveats attached to it. To give a ROM without anchoring, lead with the full range rather than a midpoint, restate the basis of estimate every time the figure is repeated, and put the caveats in writing immediately rather than trusting a verbal disclaimer to survive being retold.
The psychology: why the first number wins
Amos Tversky and Daniel Kahneman's 1974 paper "Judgment under Uncertainty: Heuristics and Biases," published in Science, described the anchoring-and-adjustment heuristic: people estimate an unknown value by starting from an initial value — the anchor — and adjusting from there, but the adjustment is almost always insufficient. In their best-known demonstration, subjects spun a rigged wheel that stopped on either 10 or 65, then were asked what percentage of African countries belong to the United Nations, a question with nothing to do with the wheel. Subjects who saw 10 guessed 25% on average; subjects who saw 65 guessed 45%. The anchor moved the answer by twenty points even though everyone in the room knew the wheel was irrelevant.
The same mechanism applies to a ROM estimate. Once a client hears a number — even a number explicitly framed as "just a rough range for planning" — that number becomes the reference point against which every later number is judged. A caveat spoken in the same breath does not neutralize the anchor; the research finding is precisely that adjustment away from an anchor is weak even when the anchor is known to be uninformative.
Why this is a commercial risk, not a soft-skills nicety
For a presales or delivery lead, an anchored client produces two specific, costly outcomes. Either they negotiate the definitive proposal against the wrong number — pushing back on a fee that is objectively fine but subjectively "higher than what you said" — or they hold the anchor against you later, treating a legitimately higher definitive price as evidence you underquoted on purpose. Both outcomes damage the deal and the relationship, and neither is fixed by having technically stated a correct range at the time.
When the risk is highest — and when it's manageable
Risk is highest when a ROM is given verbally, off the cuff, under pressure to fill an awkward silence in a first call — exactly the moment a rep is least prepared to phrase it carefully. Risk is lower, though never zero, when a ROM is presented as a written range with an explicit basis of estimate attached, because the full context travels with the number instead of a bare figure traveling alone. The wrong way is blurting a single number to end the silence; the right way treats the range itself, and what would move it, as the actual content of the answer.
How to state a ROM so it doesn't anchor
- Lead with the range, not a midpoint. Say "somewhere between $112,500 and $262,500" — never round that down to "call it $150k" or "around $190k," both of which hand the client a single anchor to fixate on.
- State the basis of estimate every time the number is repeated — verbally and in writing — covering what's included, what's excluded, and what's assumed. A number without its basis is just an anchor; a number with its basis is a starting point for a scoping conversation.
- Anchor the conversation on the range's width and its drivers, not the number itself. Explaining why the range is $150,000 wide (undefined data volume, unconfirmed integration count) gives the client something more useful to focus on than either endpoint.
- Put the caveat in writing immediately. Do not rely on a verbal disclaimer surviving the retelling — the client will very likely forward just the number to their own boss, stripped of everything you said around it, unless the range and its basis are already in an email or proposal document before that happens.
Where Managed Margin's scenario and rate-card design fits
Managed Margin's pre-sales workflow supports saving more than one staffing option for the same deal, each with its own team, price, and calculated margin, so a presales lead can compare a leaner option against a heavier one side by side rather than committing to a single remembered figure. Rate-card permissions keep the underlying cost rates visible only to Owners and Admins, so a presales user can present a calculated margin percentage without ever exposing what the team is actually paid — which supports presenting a defensible range grounded in real staffing options, without the client-facing conversation leaking the cost data behind it. See project pricing and scenario planning and the project rate card guide for the current implementation; this workflow does not remove the need to state the range and its basis out loud, it simply gives presales more than one real option to anchor the conversation around instead of one guessed number.
How this plays out on a real proposal
Consider an illustrative case: a 40-person IT-services firm is in discovery for a mid-size systems-integration engagement.
- The discovery call: the client asks the rep to "just ballpark it," and under the pressure of a pause, the rep states a single number instead of a range. Handling: rehearse the range as the default answer to that exact question before the call, so the pressure doesn't produce an ad hoc single figure.
- The internal budget slide: that single number appears, without any caveats, on the client's internal approval slide two days later. Handling: this is why the written follow-up with the full range and basis needs to go out the same day — before anyone else's summary of the call becomes the record of it.
- Mid-proposal: the actual staffing scenario built in the pricing tool lands meaningfully different from the number that was blurted in the first call. Handling: reintroduce the range explicitly — "as we said at the time, the number would move with scope; here's what discovery actually found" — rather than presenting the new number as if the first one never happened.
- Contract stage: the client references the original blurted figure as "what you told us it would cost." Handling: point to the written basis-of-estimate record sent after the call, not memory, to settle what was actually said and what it was conditioned on.
Worked instance: how a stated number reshapes the negotiation
A comparable past project's actual cost is $150,000. Applying the traditional PMI ROM band of -25%/+75% produces a range of $112,500 to $262,500 (see what is a ROM estimate for the calculation).
If presales states the bare point estimate — "$150,000" — that figure becomes the anchor. A subsequent definitive estimate of, say, $172,000 now reads as a $22,000 overrun against the anchor, even though $172,000 sits comfortably inside the correctly computed range and reflects normal scope refinement, not error.
If presales instead states the full range — "$112,500 to $262,500, and here's what would move it toward either end" — the same $172,000 definitive result reads as exactly what it is: a number inside the previously communicated range, closer to the lower half, consistent with a scope that turned out to be more contained than the worst case. Nothing about the underlying delivery cost changed between the two framings. Only the anchor did — and the anchor is what determines whether $172,000 looks like a win or a problem.
Sources and methodology
- Amos Tversky and Daniel Kahneman, Judgment under Uncertainty: Heuristics and Biases, Science, Vol. 185, No. 4157 (1974). Used for the anchoring-and-adjustment heuristic and the wheel-of-fortune demonstration.
- Project Management Institute, PM101: Estimating. Used for the range-and-basis-of-estimate framing applied throughout.
- Product statements about scenario comparison and rate-card permissions were reviewed against the current Managed Margin implementation on 6 September 2026. The proposal scenario is illustrative and not a customer result.