Learning to write is crucial as students who write well are more likely to succeed in their educational careers and in professional life (Graham, 2006). Our study focuses on synthesis writing. In synthesis writing, a writer constructs a new text based on information found in multiple sources. This is one of the most frequently required tasks in higher education. Many students experience difficulties with such tasks and produce poor quality syntheses as a result (Mateos & Solé, 2009). We carried out a national baseline study to examine the synthesis writing skills of Dutch students. More than 700 students (grade 10 – 2nd year academic bachelor) from 47 secondary schools and 3 universities throughout the Netherlands participated. All participants wrote four syntheses. Their writing processes were registered with keystroke logging software Inputlog (Leijten & Van Waes, 2013). Different aspects of the process were analysed (source use, pausing behaviour, text production and revision). The distribution of the process measures over the different phases of the writing process was taken into account (Breetvelt, van den Bergh& Rijlaarsdam, 1994). Participants also completed questionnaires, which provided us with information on different writer characteristics such as the students’ writing style (planning and revising behaviour), their attitudes towards writing and self-efficacy. Text quality was rated holistically by 48 raters, using a rating scale with benchmark texts (taking into account language, cohesion & coherence, information and integration of the sources). This study will provide insights into the writing processes, attitudes and skills of Dutch students and differences between grade levels.