In this paper, Finnish special education research is analysed. The material for this review consists of all academic theses published between the years 1951 and 1999. Doctoral theses can be considered as one type of official product of normal science, since they undergo rather stringent internal scientific evaluation. An attempt is made to evaluate the changes that have occurred in special education in relation to corresponding changes in educational science in Finland, where special education has had a close relationship with educational science. According to Husen, there was a struggle between two competing paradigms in education during the twentieth century. One was the so-called positivist paradigm, which had its roots in the natural sciences and is based on measurable and mathematically analysable empirical observations. The ultimate goal is to explain the relationships between various phenomena as causal deductions ("Erklaren"). The other paradigm looks to the humanistic sciences and attempts to understand phenomena using a holistic approach and qualitative data ("Verstehen"). The history of Finnish special education research has been divided here into three periods on the basis of qualitative development: the monopoly of the quantitative paradigm (1951-74); the period of anomalies (1975-94); and the period of movement towards the hegemony of the qualitative paradigm (1995- ).