IEEE Std 845:1999 pdf free download

IEEE Std 845:1999 pdf free download.IEEE Guide for the Evaluation of Human-System Performance in Nuclear Power Generating Stations.
3.2 Evaluation concepts
Human-system pcthwniance evaluation requires the evaluator to select appropriate measurement techniques. collect the data, and analyze and interpret the results. The selection of appropriate measurement techniques depends on the purpose of the overall evaluation and other practical constraints. Within these limits, different techniques exist that s ill be more or less suited to particular situations. This guide contains information for the selection and application of human-system performance evaluation techniques.
To interpret results, the evaluator should speci criteria for judging the acceptability of human-system performance. Without some form of acceptance criteria, the evaluator has performed only measurement, not evaluation. These criteria may be informal (evaluator’s opinion regarding the acceptability of the performance) or formal (establishing specific criteria related to the measurement: for example. operator diagnosis within a specific time limit). Other performance criteria may also be appropriate in the overall evaluation (e.g.. maintaining an adequate margin to a safety function in the operation of the planu. Ultimately. the selection of appropriate criteria should be established in the context of the overall system development process. including project goals and constraints (see IEEE Std l023-l9X8 1B31.
3.3 Characteristics of human-system performance measures
The characteristics described in 3.3.1 should be considered when selecting evaluation measures that best reflect meaningful and measurable aspects of human performance. This is not a complete list, hut represents the major characteristics that should be considered when selecting techniques. For a detailed discussion of characteristics, see ANSIJAIAA G-()35-l)92 B 11. The application of specific evaluation techniques is described in 3.4.
3.3.1 Characteristics associated with selecting human-system performance measures
— Acceptability: The degree to which evaluators at all levels agree on the use of the measure.
— Accuracy: Minimitation of measurement error.
— Applicability: Not all techniques are applicable to all phases of system design and operation. Therefore, it is important in any evaluation of human-system performance to define the applicability of the specific measures. Consider the applicability of each measure with respect to its use during design and evaluation of the system.
3.3.2 Characteristics of subjective vs. objective measures
Often, objective measures are perceived as being more meaningful than subjective measures. This is notnecessarily the case.
Subjective measures yield data that are obtained from the judgments and opinions of users or experts (e.g.judgment of task difficulty).
Such measures，while vulnerable to individual bias and perspective,are typically the most practicalmeasures available for complex or inferred behaviors (e.g.problem solving). The sources of bias insubjective measures can be controlled in most situations by attention to the characteristics described in 3.3.1.
Subjective measures,such as asking opinions on design features,may produce qualitative data. Subjective measures, such as the use of rating scales where numbers indicate the degree of response, may also producequantitative data.Statistical techniques are available for analyzing data derived from both subjective andobjective measures.Use of statistical techniques increases the formality and objectivity of performance evaluation.