We are currently living in a period where computational thinking (CT) will influence everyone in every field of endeavor (Wing, 2006, 2008). While its definition as well as its place in school curricula are still not clear, the process of integrating CT within the K-12 school system is underway. In New Brunswick, Canada, as in other parts of the world, more and more students are being exposed to a different programming and coding activities that seek to introduce CT skills such as abstraction, decomposition, algorithmic thinking, as well as pattern recognition while solving problems in a variety of technology-rich environments. Our 3-year study of innovative practices targeting the development of CT consists of three main stages: (1) the research and development of a visual data flow programming language for development of CT skills in K-12, (2) the development of a testing method based on a selection of tasks and its application to measuring CT in middle and high school students, (3) deeper investigation into the process of CT development in students, along with the elaboration of a novel testing suite in order to better detect students’ progress for each of four components of CT skills. Our findings demonstrate, along with students’ engagement and interest in solving challenging tasks, the complexity of issues that emerge from this process as well as possible paths for future investigations.