This document discusses participatory technology assessment and how it can change the world through effective public involvement. It defines participatory technology assessment as methods that actively involve various stakeholders in assessing socio-technological issues. The document outlines several principles of deliberative democracy and different models of public participation, from functionalist to emancipatory. It also reviews literature on studying the impacts of participatory technology assessment, which can include raising knowledge, changing opinions and attitudes, and initiating actions. Experimental studies and evidence from more intensive participation processes suggest participation can increase the quality, legitimacy and capacity of decisions.