This detail from a recent bid document (the bubbling is mine) made no sense to me . “Broom finish” is accomplished by taking a broom to the visible or troweled surface of fresh concrete (most commonly a sidewalk) and pushing a stiff broom over it. One does not broom form contact surfaces. This piece of precast will be poured upside down so the only available surface to broom is the bottom, which is not visible (“exposed”) when installed. Conflicting information.. Nonsense in the plan or specification. Whatever. Any specialized supplier subcontractor encounters similar stuff routinely. No big deal.
But how we respond, how we guess the best path at bid time, now that is a rich and complicated topic. I can only scratch the surface here. In this instance, the question for me was: do I assume exposed surfaces will end up being gray form finish or they will end up with an architectural finish? In most cases like this you can end up being contractually bound to either interpretation, no matter how silly or arbitrary it may seem to you. The architect who creates conflicting information gets to be the referee as well. If you do not understand that and you are in this business, I urge you to learn why this is reality and to do so before the best teacher, “Experience” hands you a sizable tuition bill.
This particular instance is a small job and I will simply do a proposal that prices it both ways. But there are many cases in which we have to predict (really guess) how these things will turn out. Most people experience such outcomes as totally unpredictable (“shit happens”). This is not the case. These outcomes may not be predictable in detail or with high confidence, but they are very far from random or arbitrary.
One important factor is the relationships between parties. While most contract documents put decision-making fully in the hands of the architect, there are many exceptions, formal and informal. To have any clue how things will turn out, to understand who will demand the ridiculous and who will surprise you by waiving a requirement, you have to understand the interests and inclinations of each party maybe even their history.
Rule #1: follow the flow of money. If the owner cares, so will the architect. Many subcontractors lose sight of the limited autonomy that architects often have. If the issue is not important to the owner then the architect may or may not care.
And of course the personality and quirks of the individual players is a major factor. The best project managers implicitly understand all this, though they may not be able to articulate it.