Brainstorming does not work.
This is old news. Dating back to the late 1950s, research shows that “all ideas are good ideas” brainstorming produces fewer ideas than if individuals are left to their own private ideations and then share and compare them in groups.
Further, evidence is solid that if you do exactly the opposite of what Alex Osborne, the “O” in B.B.D.O., espoused in his 1948 bestselling book, Your Creative Power — that is, you add the element of debate and disagreement to a typical “keep it positive” brainstorming session — the quality of ideas also increases. Dramatically so. 
A central problem, according to Rebecca Greenfield in her July 2014 article for Fast Company, is what’s called “conformity pressure.” Here’s what she says:
Because brainstorming favors the first ideas, it also breeds the least creative ideas.” She continues: “People hoping to look smart and productive will blurt out low-hanging fruit first. Everyone else then rallies around that idea both internally and externally.
What she suggests instead comes from a number of thinkers who on their own developed an idea remarkably similar, but now is referred to as “brainwriting.”
It’s simple and obvious. Participants write down their ideas first before a group discussion. They post those ideas on a board anonymously. Everyone in the group reviews those ideas and votes/comments on the best. Only then, according to Greenfield, does discussion commence. 
Greenfield notes that Leigh Thompson, management professor at the Kellogg School, in her book Creative Conspiracy, discovered that “brainwriting groups generated 20% more ideas and 42% more original ideas as compared to traditional brainstorming groups.”
Professor Thompson made this remarkable observation:
I was shocked to find there’s not a single published study in which a face-to-face brainstorming group outperforms a brainwriting group.
So what can creative brief writers learn from this research? Two things.
First, as powerful as the argument is for collaboration—the idea that no single person should write the vital “first-step” document in the creative process—individuals who make up the small team that writes the creative brief must still contribute individually before they collabrate.
Greenfield’s article (“Why brainstorming doesn’t work; try this technique instead”) demonstrates the dangers of “group think.” I think this is less likely to happen in the smaller team (two, at most three) who writes a brief, but it can still happen. One person can dominate. One person can be more senior.
Collaboration helps to eliminate at best, minimize at least, a dominate voice by employing this “brainwriting” technique before the creative brief writing team assembles to discuss and write the document. Key questions on a creative brief are uniquely difficult to answer and require thought.
Consider the way a creative team functions: a copywriter and an art director meet to review the project’s details, acquired from the creative brief. They may spend some time batting ideas around, but typically, in short order, they go off to mull over and meditate on their own.
In a day or two, they regroup and compare notes. That’s when the real work begins. They discuss, debate, edit, revise, shape, form and reform…until they arrive at a concept, or a portfolio of concepts. These ideas may bear some resemblance to their original thinking, or not.
The point is, each creative team has a process: meet, discuss, mull alone, regroup, debate, edit, polish, present. The process may vary with each team, but in 25 years as a creative, I can vouch for the importance of and need for a process.
The same must be true for the collaborative process of writing the creative brief. The team can meet for a general discussion of what the document should include, but time must be set aside for individual ideations before the team meets again to write the brief.
Second, brainwriting research makes it clear that the process of producing the creative brief may need more time to allow participants to nurture the best possible “spark” for the creative team.
I have no evidence to suggest that today’s brief writers are denied sufficient time to produce this document, except to say that the nature of the business world makes it harder and harder to build in “thinking” time for anyone.
We live in a “It’s due yesterday” time crunch. That was true when I started in the ad business in the early 1980s. It’s worse today.
However, the price you pay for a poorly conceived and poorly executed creative brief is measured in both dollars and lost time. 
I am reminded of a poster I saw on the wall of a production department manager, which sums up the dilemma succinctly, and serves as a gentle reproach:
There is never time to do it right, but there is always time to do it over.
Old-school brainstorming is dead.
Brainwriting works. Use its principles to ensure the creative brief writing team has time to do its job well.
