Wisdom of Crowds of Crowds Crowds within a crowd outperform 'wisdom of the crowd'

The wisdom of crowds suggests that many independent judgments can produce surprisingly accurate results. But discussion between people can reduce the diversity on which that wisdom depends. Research suggests another possibility: small groups can deliberate together while remaining independent of other groups, combining conversation with the wider wisdom of the crowd.

The wisdom of crowds

The wisdom of crowds is the idea that, under the right conditions, the combined judgment of many people can be more accurate than the judgment of most individuals within the group.

A familiar example is asking a large number of people to estimate how many jelly beans are in a jar. Individual estimates may vary widely, but when those estimates are averaged, the result can be surprisingly close to the correct answer.

An important part of the process is that people make their estimates independently. They are not trying to agree with one another, and one person’s judgment does not influence another’s.

This independence helps preserve the diversity of the crowd.

The wisdom of crowds of crowds

Research by Mariano Sigman and his colleagues explored what happens when people are allowed to talk together before their judgments are combined.

Rather than treating the crowd simply as a collection of individuals, they divided it into small groups. People first made their own estimates, then discussed the question in groups of five and reached a consensus.

The small groups’ consensus decisions were then combined.

The researchers found that averaging the judgments of these small groups could produce more accurate results than averaging the original individual estimates across the whole crowd.

This is interesting because it appears to combine two different forms of intelligence.

Within each small group, people can question one another, explain their reasoning, notice mistakes, and draw on different knowledge and perspectives.

At the same time, the groups remain independent of one another, helping to preserve diversity across the wider crowd.

In this sense, the process becomes a crowd of crowds.

Conversation and collective sensemaking

There is an interesting connection here with collective sensemaking.

The traditional wisdom of crowds depends heavily on independent judgments. Collective sensemaking works differently. Its value comes from interaction: people listen, question, challenge, explain, and build on each other’s thinking.

The wisdom of crowds of crowds suggests that these two approaches do not necessarily have to be alternatives. Small groups can think together while the groups themselves retain some independence.

This has some parallels with the Knowledge Café, where people hold conversations in small groups and then bring what has emerged back into the wider group.

It does not mean that the research proves that a Knowledge Café will produce better decisions. Estimating the height of the Eiffel Tower or the number of jelly beans in a jar is very different from making sense of a complex organizational or social problem.

But the research does offer an interesting clue: there may be value in combining small-group conversation with diversity across a larger group, rather than relying solely on either isolated individual judgments or one large discussion.

How can groups make good decisions?

The talk below by Mariano Sigman explains the process.

How Can Groups Make Good Decisions?

video player (source)
How can groups make good decisions? | Mariano Sigman and Dan Ariely

Mariano closes this talk with the following at 07:32 . You can read the transcript below.

Partial Transcript

Good collective decisions require two components: deliberation and diversity of opinions.

Right now, the way we typically make our voice heard in many societies is through direct or indirect voting.

This is good for diversity of opinions, and it has the great virtue of ensuring that everyone gets to express their voice.

But it’s not so good [for fostering] thoughtful debates.

Our experiments suggest a different method that may be effective in balancing these two goals at the same time, by forming small groups that converge to a single decision while still maintaining diversity of opinions because there are many independent groups.

Of course, it’s much easier to agree on the height of the Eiffel Tower than on moral, political, and ideological issues. But in a time when the world’s problems are more complex and people are more polarized, using science to help us understand how we interact and make decisions will hopefully spark interesting new ways to construct a better democracy.

video

Aggregated Knowledge From a Small Number of Debates Outperforms the Wisdom of Large Crowds

Joaquin Navajas, Tamara Niella, Gerry Garbulsky, Bahador Bahrami and Mariano Sigman (December 2018)

The wisdom of crowds suggests that many independent judgments can produce surprisingly accurate results. But discussion between people can reduce the diversity on which that wisdom depends. Research suggests another possibility: small groups can deliberate together while remaining independent of other groups, combining conversation with the wider wisdom of the crowd. Continue reading

Resources

• Wikipedia: Wisdom of the crowd
• Blog Post: Crowds within crowd found to outperform wisdom of the crowd