Early modernists focused on comparing the core technologies of manufacturing organizations. As knowledge about technology developed beyond industrial applications, modern organization theorists extended and refined their typologies to encompass first service and then task level technologies. Developing ways of measuring and comparing technology types and levels of analysis contributed new variables to contingency theory to reveal that the performance of a given social structure is not just contingent on the environment, but on technology as well. Joan Woodward, James Thompson, and Charles Perrow are the modernists chiefly responsible for adding the concept of technology to organization theory.