The Outdoor Biology Instructional Strategies (OBIS) Trial Edition Set I contains 24 varied activities which make use of crafts, simulations, and basic investigative techniques to provide introductory learning experiences in outdoor biology for children aged 10 to 15. The individual water-resistant folio for each activity includes biological definitions and concepts, materials list, preparation, action, discussion, follow up, and suggested subsequent activities. Among the activities are studies of animal movement in water, leaves, natural recycling in soil and in water, seed dispersal, ponds, natural camouflage, and predator devices. Making sun prints, mapping a study site, plant hunts, and introductory census activities are also included. Set I includes 3 introductory folios."What is OBIS?" explains the project's governing concepts and goals. The "Leader's Survival Kit" notes good activity sites, sample activity sequences, and safety information. An "OBIS Tool Box" contains Equipment and Technique Cards giving instructions for building and using various inexpensive equipment such as plankton nets and weed grapples. Instructions for each device are complete on one card. Finally, there are 2 booklets, a Pond Guide and a Lawn Guide, designed for quick and easy identification, via pictures, written descriptions, and size scales, of the most commonly encountered organisms in those locations. (SB)