* Explain that each group should begin the design process by identifying criteria for their solar water heaters. Criteria could be: low cost, simplicity, use of available materials, use of hand tools, durability (5 years), easily built and understood by non-technical people, etc.
* Explain that their plans should include: a materials list, a tools list, an estimated cost and a design drawing.
* Explain that one way for the group to decide on a design is to have each member of the group sketch as many solar water heaters as possible on notebook paper, then pick one sketch from the pile that best fits the group's criteria.
* Remind the participants that they will have only 20 hours to build and test their solar water heater, so the design should not be too complex.
* Mention that before construction can begin, each design must be checked for completeness and simplicity by the trainer and that the plans should include materials and tools lists.
* Explain that during this process, the group members should observe the group's decision-making styles since it will be discussed later in this session.
* Circulate among the small groups and offer your assistance. Do not force your ideas on the group. Encourage and support their design.
* An option here is to show the groups the copies of the solar water heater plans (from the Resources) to serve as a reference to the work they have done.