My PhD research has focused on the design, implementation and evaluation of Electronic Blocks. Electronic Blocks are tangible programming elements that can be physically stacked and arranged to form computer programs that interact with the physical world. The Electronic Blocks have been designed to provide young children, aged between three and eight years of age, with opportunities to explore technology in a purposeful and appropriate way.
The Electronic Blocks have been designed so children can connect them just as they would any other blocks. The blocks have been made by placing electronics inside Lego Duplo PrimoTM blocks. This ensures that the blocks are easy to stack and connect. The blocks have inputs and outputs and when connected, the output of one block controls the input of another. There are three kinds of Electronic Blocks: sensor blocks, action blocks and logic blocks.

There are three sensor Electronic Blocks: a seeing block, a hearing block and a touch block. These blocks are capable of detecting light, sound and touch, respectively.
Action blocks produce some kind of physical output. The light block lights a bright incandescent bulb, the sound block plays a simple children's melody, and the movement block is a four wheel car that drives in a straight line.
Logic blocks have an intermediary role. Placed between a sensor block and an action block they have the ability to alter the expected action. Logic blocks provide users with the capability to:
- produce an action if a particular stimulus is not received (not),
- toggle the input so that in the first instance the stimulus from the environment will "turn the action on" and the second instance of the stimulus will "turn the action off" (toggle),
- stretch a short signal so that the action will stay on for two seconds after the stimulus stops (delay), and
- only produce an action if input signals are received simultaneously through both inputs (and).
The Electronic Blocks are designed so that by simply playing with the blocks, children can produce interesting behaviours that they find fascinating. They might build a block tower that flashes when they talk, or moves with their touch. These are examples of simple sensor-action combinations. Given a set of three sensor blocks and three action blocks, there are a total of nine such combinations.

In the picture above, a touch block attached to a light block will cause the light to turn on whenever sensor plate is touched.
A fascinating aspect of Electronic Blocks is their ability to interact not only with the environment but also with each other. An example of two Electronic Block structures interacting is the creation of a remote control car. By creating one block stack which contains a touch block and a light block and another stack which has a seeing block on top of a movement block, a child has effectively created a remote control car. By pressing the touch block, the child triggers the light. This light in turn is detected as an input by the seeing block which actives the movement block (see the picture below).

Papers
Electronic Blocks: Tangible Programming Elements for Preschoolers
Peta Wyeth and Gordon Wyeth
Proceedings of the Eighth IFIP TC13 Conference on Human-Computer Interaction (Interact 2001).
Tangible Programming Elements for Young Children
Peta Wyeth and Helen Purchase
Extended Abstract CHI2002 Conference on Human Factors in Computing Systems.
Using Developmental Theories to Inform the Design of Technology for Children
Peta Wyeth and Helen Purchase
Small Users - Big Ideas: Proceedings of Interaction Design and Children (IDC2003), July 1-3 2003, Preston, England.
