What we build on
Every design decision we make for a child or a teen rests on what developmental science knows about their age, not on our taste alone. This page lays out what any children's project needs to know before design: the age bands and their limits, the lenses we check every decision against, the methods we use as the need calls for them, and the sources we return to and name.
The age map
The lines between bands are approximate, and their use is practical rather than theoretical: each band is designed by its own logic, not the logic of a band older or younger.
Imagination leads play more than reality does, a new word is understood from context before definition, and self-control is still in its earliest stage.
We design for Things to touch before symbols to read, and short encounters that end on time.
We avoid Long stretches of on-screen text, and a session that drags with no clear sign it is ending.
Reading turns from a skill being learned into a tool being used, logical thinking works well on what can be touched and seen, and the first real friendships take shape.
We design for A near goal whose effect shows quickly, and a comment that describes the effort, not the child.
We avoid An abstract step with no visible payoff, and praise that describes the child instead of the effort.
Logic moves past the concrete into an idea that cannot be seen, comparison with peers occupies more thought than before, and the child tries out who they are through several characters and roles.
We design for A bigger challenge than before, real creation tools, and small, tangible responsibilities.
We avoid An overtly childish look on the surface, and messaging addressed to the parent instead of the child.
Independence becomes an urgent demand, standing among friends gets measured by new yardsticks, and feelings intensify faster than the teen's ability to settle them.
We design for Small decisions the teen makes for themselves, and an address style closer to a friend's than a lecturer's.
We avoid Hidden algorithmic steering the teen cannot see, and a tone that lectures more than it talks.
The near future becomes something planned for, not just imagined, personal values settle more than before, and thinking about one's own thinking becomes possible for the first time.
We design for Clear information without alarm, and full trust in a mind nearing independence.
We avoid An exaggerated simplicity that reads as condescension, and withholding information they actually need.
Our guide in every decision
Each lens here follows one format: the question it asks, what it protects, and what it actually changes in the design.
This lens asks: is the play here free, letting the child test their own guesses, or is it bound by a clear rule? It protects the space for trial and error the child learns from directly. In design, it keeps disguised instruction off the screen, and gives the adult's role clear limits inside the game.
This lens asks: does this decision widen the child's choice, or narrow it? It protects intrinsic motivation from over-reliance on external incentives that weaken it over time. In design, it cuts reliance on daily streaks and random rewards, and replaces them with progress the child actually feels.
This lens asks: how much cognitive load does this decision carry against the age of who uses it? It protects working memory and the capacity to wait from early fatigue. In design, it cuts the number of steps for younger bands, and makes instructions something seen, not memorized.
This lens asks: what does the child learn about their feelings from this exact scene? It protects their right to name and regulate feelings rather than suppress them. In design, it turns a moment of conflict inside a story or game into learning material, not a bug removed from the final version.
This lens asks: after this design, do the parent and child talk more, or less? It protects the parent's place inside the experience from being fully replaced by a device. In design, it adds a question the child asks their family, or a small role the scene cannot complete without.
This lens asks: have real children tried this decision before it launches? It protects the child's right to an opinion heard in their own words, and their right to withdraw at any moment. In design, it makes the child's note visible in the version that actually ships, not in a report archived afterward.
Alongside the six lenses
The same format for every method: its name, and one line on when it is used.
Used when setting the youngest suitable age for a product, and when choosing between offering a symbol of a thing or the thing itself.
Used when building the difficulty curve in a learning experience, and when deciding how much help a system or person gives, then withdraws.
Used in all work aimed at the general public, with greater weight inside schools and government products.
Used wherever learning is the declared goal, not a side effect of fun: in a school curriculum, a digital platform, or an enrichment program.
No single digital product is exempt from it, and it tightens further whenever a product collects personal data or becomes the go-between for two people communicating.
Without a single exception; this is our default starting position from the first line written, not an addition requested later.
Used specifically in early-childhood work, and in any experience where we want the child and the adult to actually look at each other, not each absorbed in a separate screen.
Used wherever people work side by side with a digital system, such as a government program or a spatial experience run by a field team.
Used in any wide national or behavioral program, because a single point of intervention usually fails however much it is polished.
Used in every commitment we make to a specific effect, so that a guardrail indicator exposing unintended harm travels alongside the success indicator.
The reading we build on
These are general sources we read, not endorsements of our work. We name them as they are, and the responsibility for applying and interpreting them stays ours.
World Health Organization: physical activity and sedentary behavior
From it we take the baseline on limiting continuous sitting and favoring movement, which guides session length and pacing in our design.
UNICEF: the United Nations Children's Fund
From it we take the general frame that holds a child's protection and participation together, not one instead of the other.
General Comment No. 25 on children's rights in the digital environment
From it we take the idea that a child's digital rights are protection and participation together, not protection alone.
American Academy of Pediatrics: the family media use plan
From it we take the idea that a single rule does not fit every age, and that any usage guide needs revisiting as the child grows.
W3C: web accessibility principles
From it we take four base principles (perceivable, operable, understandable, robust) we check every interface against before launch.
Piaget, J. (1952). The Origins of Intelligence in Children. International Universities Press; Vygotsky, L. S. (1978). Mind in Society: The Development of Higher Psychological Processes. Harvard University Press.
From them we take the idea that abstract thought builds up gradually, and that the richest learning happens with light help withdrawn over time.
Deci, E. L., & Ryan, R. M. (2000). The What and Why of Goal Pursuits: Human Needs and the Self-Determination of Behavior. Psychological Inquiry, 11(4), 227-268.
From it we take the three needs that keep intrinsic motivation alive: autonomy, competence, and relatedness.
Questions about our scientific base
Yes. The science of child development keeps moving, and we do not treat any single framework as final. When what we know changes, our lenses and methods change with it, and this page gets updated rather than left as an old version.
Because a tool shown without its limits often gets used where it does not belong. Every lens here is named for what it does and what it does not, because knowing the limits of a piece of science is part of using it honestly.
An age band describes typical development, not a fixed level; one classroom can genuinely span more than one developmental band. That is why we do not rely on age alone, and we test the assumption with real children before anything launches.
Tell us about the age band and what you hope changes for it, and we will read it back to you through these lenses.
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