Anyone who has taken a small child around a museum has watched the same phenomenon. Twenty minutes of careful curatorial thought, ignored. Then a drainpipe with a ball in it, and forty minutes gone.
The drainpipe is not a failure of the museum's ambition. It is a clue, and museum researchers have spent decades taking it seriously. What they have learned is a reasonable summary of what holds a young mind, which makes it useful well beyond museums.
Dwell time, and why it is not enough
The oldest measure in exhibit research is dwell time: how long a visitor stays. It is easy to collect and it correlates with almost everything else you might want.
It is also gameable, in the way any single metric is. Flashing lights raise dwell time. So do queues. A gallery optimised purely for dwell time drifts towards a fairground.
Which is why the better research uses conversation as well. Recording what families say to each other at an exhibit gives a much richer signal: whether they are describing, predicting, disagreeing or explaining. An exhibit that generates explanation between a child and an adult is doing something a button cannot.
The difference between manipulation and consequence
Here is the central distinction, and once you have it you cannot walk through a science centre without applying it.
Manipulation means the visitor does something. Consequence means what they did changed something in a way that carries information. A button that plays a recording is manipulation without consequence: the outcome is fixed, and after one press there is nothing more to learn.
An exhibit with consequence responds differently to different inputs. A channel of water with movable gates. A rack of levers where the arrangement matters. A pile of blocks with an awkward centre of gravity. In each case the child can form an expectation, act, and be right or wrong.
This maps directly onto what is known about exploratory play, described in what play actually does. Children explore what is uncertain and abandon what is settled. An exhibit with a fixed outcome settles itself in one press.
The entry cost problem
The second thing good exhibits get right is the cost of starting. A child at an exhibit has a few seconds to work out what it is for. If the answer requires reading, or requires an adult to explain, most children have moved on.
The design solution is affordance: making the possible action visible in the shape of the thing. A handle wants to be turned. A slot wants something put in it. Good exhibits are legible at a glance and reveal their depth afterwards.
The corollary is that instructions are usually a symptom. A panel explaining what to do is a repair for an object that did not communicate itself, and children do not read repairs.
Designing for the pair, not the child
The most underrated finding in museum research is that the unit is rarely a child. It is a child and an adult, and the exhibit shapes what the adult does.
Some exhibits turn adults into supervisors, standing back and saying be careful. Some turn them into instructors, reading the label aloud and asking test questions. And some turn them into co participants, which is the version associated with the richest talk.
Exhibits that produce co participation tend to have room for more than one pair of hands, no single correct outcome, and something genuinely uncertain about them, so that the adult does not already know the answer. An adult who knows the answer asks questions to check. An adult who does not asks questions to find out, and the second sort of question is worth far more.
The same logic in libraries
Public libraries in the United Kingdom are, in the terms of this piece, an extremely well designed children's exhibit that nobody calls one. The entry cost is low. The material is open ended. Choice belongs to the child. The adult is a companion rather than an instructor.
They also have a property that no museum has, which is repetition. A child returns weekly, and the sequences that develop over months are the ones the exhibit literature says are most valuable and least measurable. The National Literacy Trust has documented the role of library access in reading engagement at length. We take the subject up separately in libraries and what they do.
Why so many children's galleries disappoint
Rarely for lack of care. Usually for structural reasons.
Exhibits with genuine consequence break, because things that respond to force get force applied to them. Fixed outcome buttons survive. Maintenance budgets therefore select against the good version.
Second, safety and throughput pull towards the fixed. An exhibit that lets a child arrange heavy objects needs supervision and space.
Third, funders like measurable outcomes, and dwell time and headcount are easy to report while the quality of a conversation is not. The metric shapes the gallery, which is a story this magazine tells about several fields, most directly in effect size in plain words.
What to look for, as a visitor
Not a recommendation of venues, since this magazine does not rank places it has not assessed, and the reason is set out on our editorial standards page. But there are things you can notice.
Does the thing do something different when you do something different? Can two people use it at once? Is there anything here the adult does not already know the answer to? Can a child start without reading? And is there any way to be wrong, because an exhibit in which nothing can fail is an exhibit in which nothing can be learned.