The beginning of a cybernetic approach is with the observer. Hie observer may be you yourself, alone or with others or someone else. Systems are not 'given' a priori. Whether or not it is a conscious process, each observer defines the system under consideration: its purpose, its boundaries, and other relevant characteristics. Observers change systems to a greater or lesser extent as they observe them. This phenomena may be immediate and substantial as in the case of a social scientist studying worker behavior, or indirect and subtle as in the case of physical sciences. An example of the former comes from Roethlisberger’s experiments varying factors such as lighting to measure the effects on worker productivity. He and his associates found improvements when the light levels were increased, and still more improvement when they were decreased, until it was practically dark. This has been called the Hawthorne effect after the Westinghouse Hawthorne plant where experiments were conducted. Another example comes from atomic physics where physicist Werner Heisenberg found limits on the accuracy of measurement imposed by die act and the means of observation. This phenomenon is referred to as the Heisenberg's uncertainty principle. Different observers in the same situation may look around them and share perceptions of a system or systems with others to a greater or lesser extent. Observers necessarily operate in an atmosphere of uncertainty because the outcome of most observed events is governed by laws of probability and statistics. When two or more observers see the same 'system' with partially corresponding purposes and characteristics, or a single observer looks at the same system from different experimental approaches and sees overlapping but not identical pictures, models of the system will be conceived which reveal somewhat different findings. In physics, this is a commonly experienced phenomenon called complementarity.

Observers are limited by their sensory perceptions, the ways in which they have been socialized or habituated to their circumstances and their thinking processes. The sensory organs may be extended through telescopes, microscopes, radar, sonar, and other instruments. The effects of socialization and habits of thought may be extended through learning and adaptation, through techniques such as brainstorming or elicitation and through spiritual disciplines. Human thinking processes are more difficult to circumvent. We may use biology and our models of animal processes to extend our understanding of perception and behavior or we may extend specific capabilities through the use of computers and artificial intelligence but even here we are not able to model or extend what we cannot first conceive. # SOURCE von Foerster, H. (1982). Observing Systems. Seaside, CA: Intersystems Press. # EXAMPLES • an experimenter conducting an experiment • an accountant conducting an audit • a supervisor inspecting work on the shop floor • the public relations staff compiling the annual report # NON-EXAMPLES • someone who conceives the system according to an incorrigible prejudice • the naive reader who accepts the accountant's report as facts • an unreflectve subject in an experiment • someone who is looking the other way # PROBABLE ERROR • Not giving enough weight to the importance of the subjectivity of the observer in determining the system observed,

• the failure to identify the observers and their purposes before applying the results of their observations in a different context • accepting conclusions without determining the observer's assumptions and choices # SEE System; Complementarity; Model