The words printed on the cover of a solicitation are the least reliable thing in the packet. One buyer calls a two-line price request a request for quotation. Another calls the identical errand a request for proposal, because that is the heading its purchasing system prints on everything. A third issues a document titled a request for proposal that scores nothing except the number on the last page.
Neither term is defined on any of the pages consulted for this article, and the omission is not a gap in the reporting. The two labels are a buyer's own vocabulary rather than a category any authority assigns, so a cover page identifies the template a purchasing office happens to run and very little else. What can be observed, reliably and from the document itself, is the rule the buyer intends to award under. That rule is the whole difference, and in a properly assembled packet it is written down some distance behind the cover.
So what follows is a key rather than a pair of definitions. It works the way an identification key works in a field guide. Each couplet offers two observations of which only one can be true of the document on the desk, and each observation is made on a different part of the packet, so a reader who cannot find the evaluation section can still reach an answer from the response form. In a solicitation assembled by somebody competent, all five couplets land on the same side. Where they disagree, the document is saying something in itself, and the last section takes up what.
Couplet one, read against the evaluation section
A. The award goes to the responsive and responsible bidder offering the lowest price, or the lowest evaluated cost, among those meeting the stated requirements. Nothing else is scored.
B. The award is decided against criteria that are listed, weighted or placed in an order of importance, and price appears as one entry in that list rather than as the list itself.
Observation A is a price instrument. Observation B is a method instrument. This couplet is decisive whenever the evaluation section exists and says anything definite, which is most of the time in public work and rather less of the time in a corporate packet. The remaining four couplets exist because the section is sometimes vague, sometimes buried in an attachment, and occasionally missing.
Couplet two, read against the description of what is being bought
A. The thing is specified to the point where two competent suppliers reading it would deliver the same item: a part number, a material grade, a quantity, a delivery date, a named standard the work has to satisfy.
B. A situation is described and an outcome is asked for. The document states what the buyer needs to be true when the work is finished and leaves the route to the supplier, sometimes explicitly inviting alternatives.
A closed description leaves nothing to compete on except price and terms, which is why it travels with a price instrument. An outcome description cannot be scored on price alone without the buyer conceding that every route to that outcome is equally good, and buyers who believed that would have written the closed version instead.
Couplet three, read against the response form
A. The form is a schedule. It has line items, units, quantities and a space for a unit price, and the only free text it invites is an exception or a substitution note.
B. The form is an outline. It carries section headings, a page allowance per section, and instructions to describe an approach, name the people who will do the work and supply references for comparable jobs.
This couplet is the most honest of the five, because a response form is the buyer's own forecast of what it expects to read. A supplier writing narrative into a schedule has produced something the evaluator has no box to put it in. A supplier returning a price sheet against an outline has answered a fraction of the questions and will be scored on the fraction.
Couplet four, read against who is named as evaluating
A. The purchasing office receives, opens and decides. No other function is named anywhere in the document.
B. A committee, a review team or a named group of staff will read and score, and the document says so, often with a note that contact with those people during the process is prohibited.
The second arrangement costs the buyer real staff time, and organizations do not spend it to compare numbers a clerk could rank. Where several functions are named as reading the submission, judgment is being exercised somewhere, and judgment has to be given something to work on.
Couplet five, read against what becomes public afterward
A. Submissions are opened at a stated time and the prices are recorded where anyone can see them.
B. Nothing is opened publicly. The document describes clarifications, presentations, negotiation or a revised submission before an award is announced.
Public opening is the signature of a price instrument, and public buyers leave the evidence standing afterward. Dallas Fort Worth International Airport keeps an announcements and tabulations area on its procurement pages, listing released solicitations alongside bid tabulations, which is the sheet showing what each bidder offered. A tabulation is only publishable because price was the thing being compared. Where an award turned on scored judgment, what a losing supplier gets is a debrief rather than a document, and the two are not the same evidence at all.
The two terminals
A price instrument makes a winning response an exercise in reading. The number has to be the lowest one that complies, so everything persuasive in the file is inert weight, and the only real levers sit before the price is written: what the specification actually obliges, which exclusions are permitted, whether the quantities are firm, and whether the work is worth bidding at the price it would take to win. Suppliers lose these on scope, not on eloquence, and they lose them by quoting a job slightly different from the one described.
A method instrument makes a winning response an exercise in scoring. The evaluator is filling in a sheet, section by section, in the order the sheet prints, and a claim without evidence attached is worth what an unsupported claim is worth. Answering in the printed order matters more than it should, because a reader hunting through a brochure for the answer to criterion three is a reader who has already scored criterion three badly. The same firm with the same capability wins one of these and loses the other, purely on the shape of what it sent.
Both terminals sit late in a longer process, and by the time either document reaches an outside supplier, the requirement it describes has already passed through several hands inside the buying organization. That earlier stretch is traced in a completed order read backward through the people who shaped it, and the routine it belongs to is set out across the section on how buyers are put together.
Where the key fails
Three kinds of packet defeat it, and all three defeat it in the same way, by carrying two award rules at once.
A staged process runs a qualification round before it runs a price round, so the early document reads as a method instrument and the later one as a price instrument, and both are correctly labeled. A heavily price-weighted proposal request scores approach and cost together, which makes the criteria list real and the arithmetic decisive at the same time. A quotation request that asks for references and insurance certificates is checking responsibility rather than scoring merit, and a supplier that treats that appendix as an invitation to write an essay has misread a threshold test as a beauty contest.
In every one of those, the key still works. It just has to be applied to the award rule rather than to the packet, and where two rules are present the document is running two processes in sequence. That is a harder thing to answer well, and it is also a thing a supplier can only discover by reading the solicitation itself, which is what the state's own posting system tells bidders to do in as many words: For instructions on submitting bid responses, please review the posting entity's solicitation and attached bid documents.
That instruction is more useful than it first sounds, because the documents are open to anybody. The Electronic State Business Daily states that signing in is not required to view what is posted there, and the entities posting to it include state agencies, universities, cities and counties. A supplier can therefore read finished solicitations in both shapes, from several kinds of buyer, at no cost and with no deadline attached, which is a cheaper way to learn the difference than discovering it inside a live bid. Where those postings appear and on what schedule is the subject of the section on where public work is advertised.
None of this makes an award predictable. It makes the question answerable before any writing starts, which is when the answer is worth having. A firm that can name the instrument in front of it knows whether it is competing on a number or on a method, and the rest of this publication's map of the ground between forming a company and invoicing a large one is arranged around distinctions of that kind rather than around encouragement.