The aim of the research project is to establish a battery for early assessment of cognitive abilities and signs of behavioral problems in children 3-5 years of age and an Early intervention program for promotion of language acquisition and use. The assess ment battery and Early intervention program will be developed in two languages - Norwegian and Bulgarian with the participation of two research teams from NTNU in Trondheim and New Bulgarian University in Sofia. There will be conducted two studies - asses sment battery testing in Norwegian and Bulgarian children and Early intervention Program testing in the two countries. The results will be compared in order to evaluate the influence of the two languages on cognitive and behavioral development as well as the influence on the effects of the application of the program. Two papers with the conclusions will be prepared and one seminar conducted. The assessment battery and Early intervention program can be used in the practice of specialist included in childho od services and they can be a base for future research and collaboration between the teams from the two universities.