RESEARCH FINDINGS ..."Preliminary findings derived from comparing the foreign language achievement of students in CLIL programmes (with many more hours of exposure to the target language and usually earlier beginning) and students in regular programmes have given estimates of the gains of the former, measured in school years. Gains of approximately two school years (i.e. 4th grade students attaining levels similar to 6th grade students in regular programmes) have been found in different studies. Results have also shown that the different language aspects may be affected to different degrees. Moreover, great variability seems to be the result of the influence of the school and the teachers" (p. 164)

Muñoz, Carme & Navés, Teresa (2007) CLIL in Spain in Marsh, David & Wolff, Dieter (2007) Windows on CLIL. Content and Language Integrated Learning in the European Spotlight. European Centre for Modern Languages. ISBN 978-90-74220-74-3. pp. 160-165