Task domain

Scientists are pragmatists, so an ES that provides advice on chemical or biological problems will be of much greater value than one that can balance the merits of Florida against those of the Costa del Sol. Expert systems address real-world problems in a well-defined, generally narrow task domain this defines the field in which the system has knowledge of value. Typical task domains include ... 

SHRDLU was an example of a system that operated in a well-defined task domain and this software was an important steppingstone in the development of AI programs, enabling computer scientists to better understand how to construct expert systems and how to handle the user-computer interaction. However, the market for software that can rearrange children s blocks is limited and the development of the first ES in chemistry was a far more significant milestone in science. 

Before any further definitions can be made, the documents to be integrated have to be modeled on type level as described above, which is not shown in this figure. Next, link types have to be defined on tjrpe level that declare types for possible correspondences on the abstract instance level. Again, for both tasks domain-specific knowledge has to be used. 

Task Domain is the area of human intellectual endeavor to be captured in an expert... 

Are there alternative metaphors that would be more appropriate for the task domain being automated ... 

Are there large, encompassing metaphors that could be used to characterize more of the task domain ... 

The challenge for a system safety analyst is in this case to identify which parts are responsible for preventing arming. The system should have at least two such independent safety features. Often they are constructed as locks that prevent the interrupter from moving. To fulfil this task domain and system knowledge is necessary. 

The first study conducted in collaboration with Paul Light and Richard Joiner (Open University, U.K.) with 11-year-old children, illustrates the overall benefit obtained from peer interaction not only during pair work but more interestingly in the children s individual performance on the post-test. The second study used a small sample of adults who were just as much novices as the children in the task domain and in the use of computers (maybe even more so since some children play video games on their home computer which might have some... 

However, the mechanisms of ACT and SOAR do not in themselves tell us much about the students initial acquisition of the skill. For instance, they do not tell us how students will read an instructional text, nor the effects of examples, nor the impact of specific pre-existing conceptual knowledge, nor the importance of having mental models in task domains that admit them, and so forth. 

The critical step in this teaching method is the task analysis that takes place in the first step. Task analysis is driven almost exclusively by the subject matter of the task domain. General cognitive theories, such as ACT, provide a notation for the rules, but otherwise offer little guidance to the person conducting the analysis. 

Logically, the only other option is to incorporate the environment into the theory. Thus, for example, a theory of physics learning would include task-specific terms like "forces" and "equations." Such theories blend psychology and the particulars of a task domain. In order to illustrate the notion of task-specific theories, let us examine some simple ones. The task of arithmetic calculation is fairly well understood. It divides cleanly into recall of arithmetic facts, such as 17-9=8, and execution of arithmetic algorithms, such as the algorithm for subtracting two multi digit numbers. We will consider a task-specific theory for recall and a task-specific theoiy for execution. 

This leads to a third option (the first two were environmental theories and task-specific theories), which is to formulate a method for generating task-specific theories. Traditionally, a method is a prescription of the kinds of experiments to run, the kinds of analyses to make and the kinds of conclusions to draw. The later two items are actually a weak task-general theory. It is weak because it does not foreordain the conclusions, but merely provides some ideas or even some notations for stating the task-specific theory. To put it differently, a method provides (1) a general theory and (2) a means of instantiating the theory to fit a task domain, thus formulating a task-specific theory. 

The analysis of procedural knowledge is one of the major contributions of cognitive science to the understanding of human cognition. Detailed analyses of cognitive skills in terms of collections of rules have been carried out for many task domains, and sophisticated techniques > computer simulation, complexity analysis, etc. - are available for investigating the properties of such collections. I believe that this contribution is permanent in the sense that future theories of human cognition will incorporate and extend on, riher than replace, these analyses. 

Once the failure modes are identified, factors that influence their generation should be determined. For example, in the requirements definition and analysis phase, a failure mode such as user is unaware of a requirement is influenced by the user s level of knowledge in the task domain. 

Definition 2 Knowledge-based systems are computer programs that encode symboHc knowledge about domains and tasks, and solve problems by manipulating this knowledge using quaHtative techniques. 

Problem Selection. To select the problem correcdy, the criteria discussed earHer should be carefully appHed before launching a project the existence of a knowledge bottleneck, the inappHcabiHty of exact numerical methods, the existence of either an expert or a theory for the task, the narrowness of the domain, and the business issues of payout and cost. If needed, the various criteria can be quantified and weighted based on their... 

An expert system is a computer program that uses an experts knowledge in a particular domain to solve a narrowly focused, complex problem. An off-line system uses information entered manually and produces results in visual form to guide the user in solving the problem at hand. An on-line system uses information taken direc tly from process measurements to perform tasks automatically or instruct or alert operating personnel to the status of the plant. 

Error probabilities that are used in decomposition approaches are all derived in basically the same manner. Some explicit or implicit form of task classification is used to derive categories of tasks in the domain addressed by the technique. For example, typical THERP categories are selections of switches from control panels, walk-around inspections, responding to alarms and operating valves. 

The psychomotor domain involves learning physical skills (such as injection of insulin) or tasks (such as performing a dressing change). The nurse teaches a task or skill using a step-by-step method. The patient is allowed hands-on practice under die supervision of the nurse. The nurse assesses die patient mastery of the skill by having the patient or caregiver perform a return demonstration under the watchful eye of the nurse ... 

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