The purpose of this study is to analyse what is happening at schools regarding the integration and use of information and communication technologies (ICT) and to examine teachers' perceptions about what teaching and learning processes can be improved through the use of ICT. A multiple-case-study research methodology was applied. From a previous exploratory research, four different types of schools were determined. Data show there is a widespread view that ICT in teaching favours several teaching and learning processes. In particular, it shows that the contribution of ICT to the improvement of teaching and learning processes is higher in the schools that have integrated ICT as an innovation factor. To attain this highest level implies that a school not only has to modernise the technological tools, but also has to change the teaching models: the teacher's role, issues regarding classroom organisational, the teaching and learning processes, and the interaction mechanisms. (Contains 6 tables.) [This article was originally published in "ALT-J: Research in Learning Technology," v18, n3, p207-220, Nov 2010.]