The purpose of this document is to describe the development, evaluation, validation and potential use of a measure of Air Traffic Control (ATC) trust. The measure, named SATI' for SHAPE ATM Trust Index', is primarily concerned with human trust of ATC computer-assistance tools and other forms of automation support, which are expected to be major components of future Air Traffic Management (ATM) systems. This deliverable is the second one developed within the Solutions for Human-Automation Partnerships in European ATM (SHAPE)' Project. A related deliverable provides a set of human factors guidelines for facilitating and fostering human trust in ATM systems (see EATMP, 2003a). A subsequent deliverable on the trust issue provides detailed information on trust principles (see EATMP, 2003b).