Erez Kikin-Gil | Interaction + Design

Light wall

The Light Wall
Tangible manipulative in Systems thinking
Key words: Physical prototyping, Illustration, Tangible manipulative, children, play, learning, learning from nature
Skills used: Physical prototyping, Illustration, game design, interaction design
The light wall Prototype

The Light Wall Overview

The Light-Wall project allows children to explore core concepts in systems thinking. It uses a representation of connected water containers to mimic the systems thinking process. In this representation, water containers stand for stocks and the tubes that connect them stand for flows. Stocks and flows are systems thinking building blocks. The stocks represent the value of an entity at a certain time while the tubes stand for flow value, the rate of change.

By connecting the water containers with the tubes, one can see how their value changes over time. By using different connections length, direction and quantity, one observes how the systems structure constantly changes, and explores systems thinking at first hand. The Light Wall use light tiles to represent the water container. Each tile is divided into two parts, an inner and an outer one. The tile parts are sensitive to pressure and change their light intensity according to it. The outer tile represents light containers (stocks) while the inner tile represents light tubes (flows).

In Light Wall, children “deposit” a certain amount of light in containers (stocks) by pressing on an outer tile for a certain time. Then they can structure paths (flows) between two containers. They can assign how much light flows in each path by pressing for longer or shorter on the inner tile. Then they can specify how long it takes the light to move from one container to the other, by structuring the path. As the child connects more and more tiles, it becomes more and more challenging to maintain the flow of light in equilibrium.


Design process

The Light Wall design takes its inspiration from the constructivist approach, especially the use of abstract objects to create concrete meaning. From the start, the design focused on finding a way that will convey the act of placing energy or matter in a container, channeling it to another container, and showing interrelations as they change. By this, children could learn about systems and change in a holistic way. They could explore and construct changing structures in an engaging way and gain insights from their peers.

The design process started with animation prototypes that I presented to my colleagues. I gained several insights from this review. One was that a narrative that would allow children to construct a proper mental model of the process should accompany the use of abstract form. Using several abstract forms to convey different meanings could help users associate the right objects with the right task. This differentiation within the unified language I designed could help users to construct better mappings of the process. Providing basic layout could help in the preliminary stages of the game.


The work on the Light Wall took three weeks. In this time, I was able to create a working prototype and present it to my peers. From the reactions I received from both peers and education specialists, I concluded that the ability to visualize paths within the systems is a promising start. On the other hand, the use of abstract form made it difficult for users to create appropriate mental models of systems thinking. Another insight was that the outputs, whether light or other sensorial stimuli, should not be subtle as the environment “noise”, such as distracting light, sound or movement, tend to dominate it.