Recent years have seen a proliferation of instructional design theories and models. Tennyson, Schott, See, and Dijkstra (1997) and Reigeluth (1999) summarize a number of these different positions. Instructional design theory, as represented in Reigeluth, varies from basic descriptive laws about learning to broad curriculum programs that concentrate on what is taught rather than on how to teach. Are all of these design theories and models merely alternative ways to approach design? Do all of these design theories and models have equal value? Do these design theories and models have fundamental underlying principles in common? If so what are these underlying first principles? The purpose of this paper is to identify and articulate the prescriptive design principles on which these various design theories and models are in essential agreement.Reigeluth (1999) distinguishes two major kinds of instructional methods: basic methods and variable methods. This paper identifies what Reigeluth calls basic methods but which I prefer to call first principles of instruction. This paper refers to variable methods as programs and practices. A principle (basic method) is a relationship that is always true under appropriate conditions regardless of program or practice (variable method). A practice is a specific instructional activity. A program is an approach consisting of a set of prescribed practices. Practices always implement or fail to implement underlying principles whether these principles are specified or not. A given instructional approach may only emphasize the implementation of one or more of these instructional principles. The same principles can be implemented by a wide variety of programs and practices. A given

pointers to exemplary work that has implications for research in educational communications and technology. This part of the Handbook consists of seven chapters covering: (1) historical foundations, (2) theoretical foundations, (3) complexity theory, (4) experiential perspectives, (5) empirical perspectives, (6) contextualistic perspectives, and (7) philosophical perspectives.

Based sn a review of instructional design models, previous papos identzJied fist principles of instmction. 7hese principles prescribe a cycle G f instruction corzsirting of activation, demonstratjon, application, and integration. 7hese instructionalphases are best implemented in the con e x t of real-world tasks. A Pebble-in-the-Pond aproach to instructional development prescribes a task-centered, content-first instructionaldc.signprocedare, which implements these fist prhciples in the resulting instructional produca. %is conc,optualpuper elaborates the component analysis and irzstructionalstrategy phases of this instrxctionul design model. %is paper &so integrates previous instructional stratzgy prescriptions fvom Component Display lheory with the content components of knowledge objects. 7he strategy for teaching within the con text of a whole task consists of applying strategy component.; to these uarious knowledge comporznts in a way that enables learners to see their interrelatiorrchzps and their relationship to the u /,ole. 7he resulting instructionalstrategy is aguided task-centered approach as contrasted with myre learnel-centeredproblem-based approdches to instructicnal design. 7he application of this C-omponent analysis and task-centered instructional strateD1 zs illustrated. (Keywords: Pebble-z q-the-Pond instructional design, jrst prz nciples of instrtictzon, Component Display lheory, inowledge objects, task-centered instruction, whole-task irzsti.uction, task progression, knowleqe and skill components, component analysis, instructiorzal strategies.)