Change

A difference in the VALUEs of a variable and in time. A difference in a system 's state s observed at different times. Change is basic to any process. Speed is a measure of change in an Euclidean Space and is expressed as the proportion of distance travelled to elapsed time. Gradual change implies ordered variables or continua such as temperature, weight, distance, Gross National Product and observations at smaller time intervals yields intermediate values thus revealing a curve in a space-time continuum. Qualitative change is considered abrupt and refers to differences in structure, pattern or level which usually imply mutually exclusive descriptions, attributes or LAWs e.g., changes in the form of matter from gas to liquid to solid or transitions from a feudal to an industrial society. Quantitative changes are changes in numerical or mass variables such as in volume, wealth or transmission rate. Quantitative changes may be gradual as in population growth or occur in larger units or steps as in salaries. Quantitative changes may become qualitative when they pass the threshold of mutually exclusive types supported by the quantities involved, e.g. changes from an industrial to an information economy. (Krippendorff )