The earliest example of equine footwear we have is made of animal hide and dates from about 600 B.C. This primitive hoof protector looks more like a horse bootie than what we think of today as a horseshoe. It was probably stuffed with dried grass or other available natural material and tied on with hide thongs.
The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. The spiral model was defined by Barry Boehm in his article A Spiral Model of Software Development and Enhancement from 1985. This model was not the first model to discuss iterative development, but it was the first model to explain why the iteration matters.
Introduced as a conceptual model in the 1970s, formalized as a theory in the 1980s, and continually revised by Bronfenbrenner until his death in 2005, Urie Bronfenbrenner 's Ecological Framework for Human Development applies socioecological models to human development.wo distinct phases of the theory can be identified. Bronfenbrenner stated that it is useful to distinguish two periods: the first ending with the publication of the Ecology of Human Development (1979), and the second characterized by a series of papers that called the original model into question..