the Open University. Systems practice In the later years Vickers wrote and lectured on the subject of social systems analysis and the complex patterns of social organisation. His work was taken up by researchers at the Open University in particular. Vickers is regarded as a systems practitioner rather than an academic. He introduced the concept of appreciative systems to describe human activity. He recognised that appreciation of systems requires the participation of not only the observer, but also that of the subject. Appreciative systems and appreciative behaviour Much of his work is devoted to the analysis of judgement in terms of what he called 'appreciative behaviour': this is described most effectively in The Art of Judgement (1965). He believed that social institutions are best analysed as systems, and his published work, notably Human Systems are Different (1983), made far-reaching contributions to systems thinking in its applications to human society. Vickers coined the term "appreciative system" in his 1968 article "Science and the Appreciative System" to refer to "the activity of attaching meaning to communication or the code by which we do so". In "Human Systems are Different" (1983) Vickers explained: I find it surprising that we have no accepted word to describe the activity of attaching meaning to communication or the code by which we do so, a code which is constantly confirmed, developed or changed by use. I have for many years referred to this mental activity as ”appreciation'; and to the code which it uses, as its ”appreciative system‘; and to the state of that code at any time as its ”appreciative setting'. I call it a system because, although tolerant of ambiguity and even inconsistency, it is sensitive to them and tries to reconcile them. In a 1978 interview Vickers added: I'm interested in Systems from the personal up to the very large, human, social systems, I'm also interested in systems of concepts and values through which we see all the others which I call appreciative systems. A response by Peter Checkland in his "Systems Thinking Systems Practice": <blockquote>Vickers argues that our human experience develops within us 'readiness to notice particular aspects of our situation, to discriminate them in particular ways and to measure them against particular standards of comparison...' These readinesses are organized into an 'appreciative system' which creates for all of us, individually and socially, our appreciated world....The appreciative settings condition new experience but are