The candles, the matches and the tacks were already in the boxes. People tried to pin a candle to the screen. The platform they needed was the thing they were using to hold the tacks. The new idea never had a chance while the old job was still sitting on the part.
Robert E. Adamson repeated three of Karl Duncker's problems in Functional fixedness as related to problem solving, Journal of Experimental Psychology, 1952. Duncker had run them with 14 people, and Adamson thought the conditions were too loosely specified to trust. Adamson used 57 college students from elementary psychology classes, 35 men and 22 women. Twenty-nine were in the experimental group and 28 in the control. If you are about to pay for a day of ideas, the useful part is what the box was doing when the person first saw it.
The box arrived full
The first problem asked a person to mount three candles vertically on a screen, at a height of about five feet, using the objects on the table. Among them were three pasteboard boxes, five matches and five thumbtacks. The solution is ordinary once you are allowed to see it. Melt wax on a box, stick a candle to it and tack the box to the screen. One candle on each box. The box has to stop being a container and become a platform.
For the experimental group the candles, the matches and the tacks were placed in the three boxes before the problem began. The boxes arrived already doing a job. Duncker called that group the after pre-utilisation group. The control group got the same objects without that prior job. The empty boxes sat on the table at varying distances from the candles, the matches and the tacks. Nothing crucial had been used for something else first.
The other two problems made the same demand with different objects. The gimlet problem asks a person to hang three cords from a board on an overhead beam. Two screw-hooks and the gimlet itself can hold the cords. In the experimental group the gimlet had first been used to start the holes. In the control group the holes were already drilled, so the gimlet had no earlier job. The paperclip problem asks a person to attach four small black squares to a large white square and hang that square from an eyelet. A paperclip, bent into a hook, does the hanging. The experimental group had first used paperclips to attach the small squares. The control group found those squares already stapled on.
What the prior use did
Each person had at most 20 minutes a problem. On the box problem the experimental group was markedly worse, both in how many people solved it and in how long the solvers took. Only 12 of the 29 who had first used the boxes as containers solved it. Prior use as a container inhibited use as a platform. The control group, who saw empty boxes, did better on both counts. Adamson treated that as confirmation of Duncker. The old function was not a hint. It was a lid.
The other two problems show why a room that eventually finishes is not evidence that nobody was stuck. On the gimlet problem only three people failed, and all three were in the experimental group. Almost everyone got there. The time still separated the groups, and the difference was highly significant. On the paperclip problem every person solved it. The experimental group was still slower. A workshop that scores only whether the team produced an idea will miss the delay. The prior use did not always block the answer. It taxed the minute in which the answer could have appeared.
Adamson dropped one of Duncker's measures, the count of wrong attempts before the solution, because it depended too much on the experimenter's judgment. Number of solutions only separated the groups on the box problem, because almost everyone solved the other two. Time did the separating on all three. A buyer who asks only whether the wall filled up is using the measure that failed on two of the three problems. Ask how long the current use sat on the part before anyone moved it.
Talk to the people who use it
One easy misreading does not survive the split. The control group was not a room of more creative people. They were the same classes, divided so that 29 saw the prior use and 28 did not. The difference was the job the object already had. A sponsor who explains a dull wall by the quality of the team has skipped that split. Put the same people in front of parts that arrive already employed and you should expect the experimental result, including from people who would have seen the platform if the box had been empty. The day is allowed to change the arrival. It is not allowed to pretend the arrival was neutral.
One solver is not the room
Adamson then asked whether the person who was quick on one problem was the person who was quick on another. He split the experimental group around the median time, and for the box problem around solved or not solved, because only 12 of 29 solved it and a median time could not be taken. The box problem and the paperclip problem were related, at the 0.05 level. The other pairings were not. He is plain about what that means. Achievement on a single problem that begins with a prior use is not a reliable measure of who is susceptible.
A proposal that points at one volunteer who emptied the box, and treats the room as fixed, has used the measure he already found unreliable. The person who sees the platform on a candle problem may not see it on the next object. The day has to put the prior use in front of more than one part, and more than one person has to take it off. A highlight reel of the clever table is the single problem. It will not tell you who will still be stuck when the object changes.
What an idea wall gives away
Read the running order before you book. If the current process stays intact while people produce options, the boxes are still full. The options will be ways to pin the candle harder. Stickier notes, a new colour, a faster version of the same container. If the first hour is a tour of the product as it is sold today, the prior function has been rehearsed, which is the experimental condition, not the control. Empty boxes were the easier room. A day that begins by admiring the current job has chosen the harder one and then acted surprised.
The control was not a lecture about being open. Nobody told those students to think differently. The objects arrived without a job already stuck to them. You cannot ship that literally. A live process arrives with its job on. The substitute is a deliberate emptying, done out loud, before the options. Name the part. Name the use it has today. Take that use off, on paper, and only then ask what the part could hold. Skip that and you are timing people who are still looking at a full box.
What a later task should show
Bring one process the team already runs. Break it into parts a person could point at: a form, a queue, a handoff, a screen, a rule about who may say yes. For each part, write the job it has this week. Then write one job it cannot do while that use is still on it. The candle cannot sit on the box while the tacks are in it. The second sentence is the one a weak day never asks for. People will list features to add. They will not name the use that has to come off.
The standard I would take into a proposal is small. Did they empty at least one part before anyone proposed a replacement. Did more than one person do it, on more than one part, because a single solver is not a measure. Did the slow table get as much attention as the fast one. Adamson's time result is the warning. A table that finishes can still have paid the tax. If the only record is a photograph of a full wall, you bought the measure he discarded.
Be willing to let a current use die in the room. The box does not become a platform by being praised as a box. Someone has to tip it out. A sponsor who needs every existing step to survive the afternoon has booked the experimental condition and forbidden the solution. Say that before the day, not after the wall is covered in ways to keep the tacks where they are.
What the room has to be allowed to hear
The awkward sentence is the one that names a use people are proud of. The weekly pack, the approval chain, the dashboard that proves the team is busy. Each of those can be a box that arrived full. Calling them valuable is not the same as asking what they are preventing. A room that is only allowed to add, and never to tip a box out, will produce a longer version of the process it walked in with. The candles will be better candles. They will still be in the box.
Collective Campus has done capability building for teams since 2015. The design thinking workshop is for a team that can bring a live process and is allowed to take its current use off the parts. What the notes have to become before anyone ideates is in what the day must show before the ideas. What the agenda should cover once that is settled is in what a corporate design thinking workshop should cover. A feature that left before anyone had the problem is in the feature the customer never asked for.
What to bring
Bring one process, the parts it is made of and permission to take a current use off at least one of them. If every part has to leave the room doing the job it arrived with, the box stays full.
