E Wedman is Associate Professor of Educational. Technology, Department of Curriculum and. Instruction, University of Missouri, Columbia,. MO 65201.
A Layers-of-Necessily Instructional Development Model []
Martin Tessmer John E Wedman
Martin Tessmer is Associate Professor of Instructional Design in the Department of Instructional Technology, Media, and Telecommunications Division, University of Colorado at Denver, Denver, CO 80204-5300. John E Wedman is Associate Professor of Educational Technology, Department of Curriculum and Instruction, University of Missouri, Columbia, MO 65201.
Instructional design and development models are sometimes criticized for being unnecessarily complex and for requiring an unrealistic amount of precision. To counter this criticism, some will argue that the complexity and precision are necessary to help ensure a quality instructional product. This article offers a solution to the problem of practicality versus precision by introducing a "layers-of-necessity'" model of instructional design and development. By recognizing that instruction evolves over time rather than emerges fully developed, the model offers an alternative means of achieving quality instruction.
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[] The primary responsibility of an instructional developer is to design and develop instructional solutions to performance problems. To m e e t this responsibility, m a n y developers use a model to guide the instructional design and development process (And r e w s & G o o d s o n , 1980). Many of their models are patterned after what Maher and Ingram (1989) refer to as the "sequential waterfall model." In the waterfall model, the output of one phase in the process serves as input to the next phase. The waterfall model is illustrated in Figure 1. In many respects, Dick and Carey (1985) offer a good example of an instructional development (ID) model based on the sequential waterfall model. The Dick and Carey model (see Figure 2) begins with identifying instructional goals. The output of this component serves as input to conducting instructional analysis and identifying entry behaviors. The outputs of these steps serve as i n p u t to writing p e r f o r m a n c e objectives which, in turn, provide the basis for developing test items. Next, the instructional strategy is developed. The instructional strategy and earlier outputs guide instructional materials development. Finally, the instruction is field tested and revised if necessary before full-scale implementation and summative evaluation are undertaken. Dick and Carey indicate the model components are " . . . in the sequence typically followed when designing instruction" (p. viii-ix). The Dick and Carey model is widely known among ID professionals. Not only is the Dick and Carey text very popular in in77
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Phase 1 Phase 2 Phase 3 Ph~e4
FIGURE 1 [ ] Sequential Waterfall Model
troductory ID courses, the model is used in other ID books (e.g., GagnG Briggs, & Wager, 1988). The model and its components are far from unique, however. In fact, an examination of Andrews and Goodson's (1980) comparative analysis of ]D models leaves the distinct impression that m o s t ID models are more alike than different, at least in terms of which components are included in the various models, if not in terms of how the components are related. In addition to sharing generally agreed u p o n c o m p o n e n t s , m o s t ID m o d e l s have other c o m m o n traits. For example, all components are considered "required"; none are given "optional" status. Each component also appears only once in the model; a component is usually not reconsidered unless "tryouts" indicate that revision is necessary. Finally, each component is fully executed; no component has a "good-enough-for-now" indicator that adjusts to the exigencies of time
and resources. For example, the Dick and Carey model does not allow for conducting an instructional analysis that does not include identifying all subskills and related verbal information. Indeed, the implicit assumption is t h a t failure to c o m p l e t e the instructional analysis will severely affect the effectiveness and efficiency of the resulting instruction. Collectively, these c o m m o n traits point out a limitation found in many ID models: the models prescribe a level of detail and complexity which is difficult, and sometimes impractical, to obtain in practice. Rogoff (1984, p. 63) echoed the sentiment of many practitioners: "These models may be fine for theoretical study in graduate courses on instructional technology. As a trainer in industry, however, I find that a simpler, more pragmatic approach works better." Unfortunately, the ID literature offers little help in reaching a less desirable, but oftentimes necessary, g o a l - - g o o d - e n o u g h - f o r - n o w instruction (i.e., instruction good enough to improve, but p e r h a p s n o t optimize, p e r f o r m a n c e within the givens and limitations of the situation). What is needed is a "practitioner's model" of instructional design and development. A practitioner's model of ID is a representation of what exists today, of what developers do on the job. It accommodates a range of developer expertise and practice, from extremely simplified to highly complex and sophisticated approaches.
I I I I
1
t! |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FIGURE 2 [] Dick and Carey ID Model
I
A LAYERS-OF-NECESSITYID MODEL
A practitioner's model is consistent with Simon's notion of "satisficing" (1981, pp. 3637) which involves selecting an action which will get the job done while not necessarily in an optimal manner. Consequently a practitioner's model accommodates the most sophisticated design and development strategies as well as the "lean" approaches often practiced but seldom advocated by ID professionals. Lean, simple approaches to ID are seldom described in the literature; additional detail and precision is a more likely topic of discussion. What does a developer do when, out of necessity, a complex ID model cannot be followed? The following section describes a new m o d e l - - t h e layers-of-necessity model. The model has b e e n u s e d by the a u t h o r s and found to be sensitive to time and resource constraint problems without sacrificing the integrity of the ID process.
LAYERS-OF-NECESSITY MODEL
• task closure versus task enhancement
The essential perspective of the layers-of-necessity model is this: based u p o n the time and resources available to the developer, the developer chooses a layer of design and development activities to incorporate into an instructional product or project. The layer is matched to the necessities of the project. Individ-
Simple ID Process
ually, each layer is a self-contained ID model. Collectively, the models differ in terms of design and d e v e l o p m e n t sophistication (see Figure 3). For situations with severe time and resource limitations, only the simplest layer may be possible; for situations with more time a n d resources, a m o r e sophisticated layer may be used. A developer can choose to start with any layer (i.e., model) that suits the situation. If additional time or resources are available, however, after completing the initial layer of design and development activities, additional design and development features can be drawn from more sophisticated layers and incorporated into the product or project. The model is further described below by c o m p a r i n g it to m o r e t r a d i t i o n a l ID models. Then an application of the model is offered to illustrate its utility. W h e n the layers-of-necessity m o d e l is compared to more traditional ID models, several critical differences become apparent:
• procedure-based versus principle-based design • discrete stages versus merged stages • comprehensive versus opportunistic perspective • e f f e c t i v e n e s s - b a s e d v e r s u s efficiencybased.
Limited Time/ Resources
ID Process
ID Process
ID Process Layer 3 / ',%
...............
ID Process Layer 'n'
.............. " Ample Time/
Complex ID Process
Resources
Quality FIGURE 3 [ ] Layers-of-Necessity Model
,/
~ Task Closure Versus Task Enhancement
In most ID models, design and development tasks are approached as discrete, sequential components, one after the other. Based on an information processing framework, the output of one component serves as input to the next. While these models may have iterative features that allow for a reconsideration of earlier design activity outputs, they emphasize closure of each component in the process to serve as input to the next component. Thus, a needs analysis is typically completed before moving on to a content analysis and so on. Earlier components may be iteratively revised based on subsequent information, but the process is essentially one-way. In contrast, a layered approach assumes that components of the ID process will be repeated to a greater degree of precision and sophistication in subsequent layers of the process. This repetition is not for the purpose of revising earlier components (as iterative models suppose), but of adding onto the work that was done earlier. Obviously, such additions may entail revisions in earlier work, but this is not the major purpose of the next layer of a design/development component. Rather, the purpose of subsequent layers is to enhance the work that was previously completed. For example, when designing and developing computer-assisted instruction, the initial layer of instructional strategies developm e n t m i g h t be limited to d e v e l o p i n g presentation and practice/feedback elements to be included in the software. Where time and resources permit, another layer of instructional strategy development might include specifying learning control options, adaptive practice and feedback, and remediation modules.
Procedure-Based Versus Principle-Based Design
Many traditional ID models suggest a procedural perspective on the design and development process. The process is described in terms of steps or stages to be completed in a
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prescribed sequence. McCombs (1986, p. 73) referred to this as "overproceduralization" of the process and argued that such a perspective undermines the quality of resulting instructional products. A layered approach suggests that principles, not procedures, should govern design and development activities. This perspective suggests that ID is based upon two sets of principles or guidelines. The first set of principles ("Layer-Selection Principles") determines which [D activities are appropriate given time and resource constraints. The second set ("Layer-Implementation Principles") governs how the various design and development activities are implemented. Each set is described below. Layer-selection principles are used to determine which ID activities will be incorporated within the constraints of a given project. One selection principle is that the precision of an ID activity is a function of the ease of achieving that precision. For example, a few general goals (less precise) might be more appropriate than a detailed list of specific objectives (more precise) if the developer cannot, for whatever reason, generate the detailed list in a timely manner. In such a situation, the developer should select an ID model (i.e., layer) that does not require listing specific objectives. This and other selection principles (beyond the scope of this paper) use a cost-benefit perspective to determine the initial layer of design and development activities. Layer-implementation principles are used to determine how the ID activities within a given layer are carried out. One such principle is that the output of all activities should be consistent with each other. For example, it is critical that practice exercises be consistent with the desired learning outcomes. While preparing practice exercises, however, the developer may discover that what was initially described as a desired outcome is not truly job relevant. Consequently, parts of the instruction will need to be reconsidered and perhaps revised. Likewise, if additional time and resources were available to enhance the instruction (e.g., replace a simple role play with a complex case study), the consistency principle helps ensure that the enhance-
A LAYERS-OF-NECESSI1ID Y MODEL ments are consistent with other development components.
Discrete Stages Versus Merged Stages In a sequential ID model, each component of the process has its own identity. Such a model typically emphasizes working on a particular type of task, which is usually one of the "boxes" of the model. In a layered approach, discrete tasks are not as important as the layer itself. Each layer is a merged set of tasks or questions that cut across the discrete stages of traditional models. Layers are not distinguished by the type of task per se, but by the level of complexity associated with the tasks in that layer. The discrete tasks of a layer are unified by virtue of their common purpose: adding to product design/development within project constraints.
Comprehensive Versus Opportunistic Perspective Most traditional models imply that all components of the model must be accomplished in the project, one after the other. No provisions are made for minimizing or deleting a component. In this sense, the models are comprehensive, prescribing what ought to be done. As argued earlier, however, these prescriptions are sometimes ignored when working to complete an ID project. In a layered approach, components may be minimized or deleted, just as they are in practice, depending upon the constraints and goals of the project. In this sense the model is opportunistic, identifying what can be done within project boundaries. For example, with little time, a needs assessment might be limited to asking the clients why they want the project done; task analysis might be a 10minute discussion about the general procedure for accomplishing a task. A layered approach is sensitive to the balance between project scope, available resources, and timelines. For any given ID project, the project parameters of scope, resources, and timeframe
8t can be adjusted to complete the project. When resources and/or time cannot be altered to any significant degree, the project scope must be altered (e.g., eliminate some course goals). In those cases where the project scope cannot or should not be altered, a layered approach can be used to adjust ID activities within resource and time constraints. The complexity and sophistication of the ID activities in a layer is determined using a cost-benefit approach to design: select activities that are likely to have the greatest instructional benefit for the least resource/time cost.
Effectiveness-Based Versus Efficiency-Based Design Traditional models indicate that each component of the ID process must be thoroughly accomplished in order to develop instruction that is maximally effective. The goal of a typical ID project is mastery of the learning objectives by the greatest number of learners possible. In this sense, the models are time and resource intensive; time and resources should be dedicated to the design and development activities prescribed in model. The traditional purpose for using a model is to promote effective instructional design and development. A layered approach seeks to develop effective instruction as well, but effectiveness activities (i.e., design and d e v e l o p m e n t tasks) are determined by what can be done in the situation, not what ought to be done. For example, what can a developer accomplish with only 20 hours and $2,000 that will make the project effective? In this sense, a layered approach is time and resource sensitive; it implies that ID activities should first be adapted to the time and resource constraints of the project. The purpose for using a layered approach is to promote efficient instructional design and development. Given these general features of a layered approach, the discussion now shifts to an application of the layers-of-necessity model. Two examples are offered. In the first example, time and resources will be assumed to
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be very limited. In the second example, these constraints will be relaxed. It is important to note that the ID components used in the examples are offered to illustrate the dynamics of the model, not to prescribe a particular set of activities; other combinations of components can be accommodated by the model.
Example 1 When time and resource constraints are significant, the ID process might be limited to five basic components: •
Situational Assessment
•
Goal and Task Analysis
•
Instructional Strategy Development
• Will instruction improve performance? • Who will receive the instruction? • What are the resource and time constraints? If time constraints are significant, more indepth questions are inappropriate; detailed analysis should be avoided. If more time and additional resources (e.g., personnel) are available, the developer can move to a more detailed situational analysis by adding one or more layers of analysis. These additional layers are described later. Goal and Task Analysis involves answering the questions:
• Materials Development • Evaluation and Revision These components comprise the highest (i.e., simplest) layer of the model. The components are described below; their relationship is illustrated in Figure 4. Situational Assessment begins when a performance improvement need is identified. At this layer, the assessment is limited to identifying the instructional needs in terms of content topic(s). Essentially four questions are asked: • What performance improvement is required?
•
What is the instructional goal?
•
What will the performer do when performing the goal?
• What learning domains are involved? Here the developer interacts with the subjectmatter expert and/or subject-matter materials to develop a conceptualization of the performance task. The analysis is limited to some form of task analysis (Jonassen, Hannum, & Tessmer, 1989). In-depth subskills analysis, objectives writing, and test development are not conducted unless additional time and resources are available, in which case additional layers in the model will be accessed.
FIGURE 4 [] Layers-of-Necessity Model: Simple Application
A LAYERS-OF-NECESSflYID MODEL
Once the goal and tasks are analyzed, Instructional Strategy Development can begin. The questions being asked are: • Given the learning domain(s) and audience, w h a t instructional strategies are most likely to be effective and efficient for the instructional outcome? • What strategy will work within the situational constraints? When time constraints are significant, attention is directed to selecting the instructional strategy most appropriate for the learning domain (e.g., use modeling strategies with the affective domain, memorization strategies with verbal information). Little if any attempt is made to tailor the strategy to match the type of subskills involved in the learning task (e.g., systematically varying the range of practice opportunities to insure against over- and under-generalization of a concept). If time and resources allow, additional layers with subskill-specific strategies can be added. Materials Development in the layers-of-necessity model is driven by the instructional strategy, time constraints, and resource constraints. The question to be addressed is: • What materials can be used to deliver the instruction in a timely and economical manner? Here the select-modify-develop rule applies: select from or modify existing materials if time and resources are limited; develop new materials only if the situation allows. For example, to overcome time and budget constraints, an operations manual might be used in lieu of developing a student manual in an equipment operations course. W h e n time and resource constraints are relaxed, more sophisticated media and materials can be developed and greater attention can be paid to message design. Evaluation and Revision are critical components of the model, even at the highest level. Three questions are appropriate: • Is the content accurate? • Is the instructional strategy adequate?
83
• What revisions must be made before fullscale implementation? Frequently, the most expeditious way to determine content accuracy is to check with a subject-matter expert. The adequacy of the instructional strategy can be verified, albeit in a limited manner, through a single one-toone formative evaluation (Lowe, Thurston, & Brown, 1983). Multiple one-to-one, small group, and large group trials are not conducted at this layer in the model but can be a second or third layer activity if time and resources are available. Before continuing to examine other layers of the model, a critical point must be made. The layers-of-necessity model is as much a way of thinking about ID as it is a perspective one brings to the ID process. Clearly each of the components just discussed could be expanded to include many additional activities. It is, however, sometimes not feasible to conduct a comprehensive front-end analysis, to develop detailed learner profiles, or to match the instructional strategy carefully to each content element. These and many other tasks are included in the layers-of-necessity model but are found in deeper layers. Depending on how the developer allocates time and resources, deeper layers are used in the process. This is illustrated in the second example.
Example 2 When time a n d resource constraints are less severe, other layers in the model can be accessed. As shown in Figure 5, each of the five components described above has one or more additional layers associated with it. Each layer adds additional design and development features to the resulting instruction. To illustrate, assume that a developer has the time and resources to go beyond the initial questions asked in the situational analysis. The next layer offers a new set of questions: • What is the performance discrepancy? • Does the discrepancy result from inadequate information, e n v i r o n m e n t a l constraints, improper reward and incentive
ETR&D,Vol.38, NO,2 Cognitive Style Assessment Learner Preassessment
Field
Needs Assessment
Evaluatior
Obiective writing
Multiple One-to-One
SubskiU Analysis Test Development
Events of Instruction
Student Manual
Motivational Strategies
Presentation edia Self-Paced ~ ' ~ Materials Media
..._._.•M
Display Theory
FIGURE 5 [] Layers-of-NecessityModel: ComplexApplication
plan, knowledge/skill deficiency, or other performance-related factor? $ What prior knowledge does the learner have related to the instructional goal? The answers to these new questions, along with the answers provided in the previous layer, will probably increase the quality and utility of the resulting instruction. The tradeoff comes, however, in terms of time and resource consumption. Simply put, some questions are best left unasked if time is not available to answer the question or to act upon the answer. In those situations where time and resources are in abundance, additional layers can be included in the model. For example, the situational analysis can be expanded further to include cognitive style assessment. Likewise, noninstructional solutions might be developed to address those aspects of the performance discrepancy not resulting from a knowledge or skill deficiency. The devel-
oper should, however, be aware that these layers are very time and resource intensive. In many respects the layers-of-necessity model is not a new model but rather a new approach to using existing (and presumed familiar) models and strategies in an integrated, practical manner. For this reason, a detailed description of the remaining layers is inappropriate and unnecessary. In the section which follows, suggestions for using the model in practice are offered.
USING THE LAYERS-OF-NECESSITY MODEL
The key to using the layers-of-necessity model lies in the realistic assessment of the time and resource constraints associated with a particular design and development project. The motto "Better-Cheaper-Fasterm Pick Two" is clearly operative. By providing multiple layers of design and development
A LAYERS-OF-NECESSITYID MODEL
sophistication, the model becomes a tool for managing the quality, budgetary, and scheduling expectations of the client requesting the instructional product. Other than working within time and resource constraints, the model currently does not include prescriptions regarding the relative depth of design and development across the major components in a given layer. Three guidelines can be offered, however. First, the developer should be cautious about using a deep layer of one component and shallow layers for others. For example, if the situational assessment, goal and task analysis, and instructional strategy development were very limited, it would be unwise to expend considerable time and resources on materials development. The second guideline might best be described as "touching all the bases." When using the layers-of-necessity model, the developer is committing to at least one layer in each of the basic components. If there are five basic components (as was the case in the first example), then the design and development activities will address each of these five components. Failure to address any one component jeopardizes the investment made to the other components in the process. The final guideline stems from the dynamic, o p e n n a t u r e of the model. Unlike m o s t ID m o d e l s , t h e l a y e r s - o f - n e c e s s i t y model can be personalized based on professional expertise and judgment of the individual developer. New and different strategies can be integrated into the model by either modifying existing layers and/or adding new layers. For example, a developer may determine that the five components used earlier in the first example are sometimes too timeintensive for projects in his/her organization. The developer can (and should) add a simpler, less time-intensive layer to the model.
85 CONCLUSION
In m a n y respects the layers-of-necessity model is both a new perspective and a new framework for instructional design. As a perspective, the model offers practitioners a context for reflecting u p o n their daily design activities. As a framework, the model offers theorists a comprehensive, practical context in which to cast their work. By bridging the g a p b e t w e e n ID t h e o r y a n d practice, the model offers a systematic way of achieving quality instruction. []
REFERENCES
Andrews, D. H. & Goodson, L. A. (1980). A comparative analysis of models of instructional design. Journal of Instructional Development, 3 (4), 216. Dick, W. & Carey, L. (1985). The systematic design of instruction. (2nd ed.). Glenview, IL: Scott, Foresman & Co. Gagn~, R. M., Briggs, L. J., & Wager, W. W. (1988). Principles of instructional design. (3rd ed.). New York: Holt, Rinehart, Winston. Jonassen, D. H., Hannum, W. H., & Tessmer, M. (1989). Handbook of task analysis procedures. New York: Prager Publishing Co. Lowe, A. J., Thurston, W. I., & Brown, S. B. (1983). Clinical approach to formative evaluation. Perf0rmance & Instruction, 22(5), 8-11. Maher, J. H. & Ingram A. L. (1989). Software engineering and ISD: Similarities, complementarities, and lessons to share. A paper presented at the 1989 Annual Meeting of the Association for Educational Communications and Technology, Dallas, TX. McCombs, B. L. (1986). The instructional systems development (ISD)model: A review of those factors critical to successful implementation. ECTJ, 34(2), 67-81. Rogoff, R. L. (1984). The training wheel: A simple model for instructional design. The Magazine of Human Resources Development, 2•(4), 63-64. Simon, H. A. (1981). The science of the artificial. Cambridge: MIT Press.
