Background
In the Netherlands, there has been a strong increase in diversity among students in recent decades. Even though access for previously underrepresented groups based on economic status, ethnicity or culture has been realised to a certain extent, differences in student performance between groups persist. Research shows that teacher performance influences student achievement and that this influence is more pronounced for 'non-western students'. This creates a need for reflection on the way teachers cope with their increasingly diverse student population. This paper explores the attitudes of Dutch teachers in higher vocational education towards their diverse student population and the translation of these attitudes into teaching practice.

Methods
Twenty-five teacher teams at two universities of applied sciences participated in this research. The teams came from a broad range of programmes that educate students for different future professions. A mixed method methodology was used to gather data, in which the qualitative method was most substantial. Focus group interviews on diversity and student achievement were held with each teacher team. Additionally, a questionnaire was distributed to all 274 participants, which was completed by 215 teachers. Data from the questionnaire were analysed using SPSS. In order to analyse the qualitative data we used AtlasTI. Because we applied a grounded approach, allowing teachers to form their own ideas on both diversity and student achievement, we used a similar approach in the first analytical phase. In a second phase, we compared the concepts arising from the grounded theory approach with concepts from the literature.

Results and conclusions
Around 40% of the teachers repudiated the influence of diversity on student achievement and did not take student diversity into account in their teaching practice. Problems regarding the student achievement of students or groups thereof are considered as something that the students, the educational institution or society at large should cope with, not teachers themselves. Of the teachers, 60% recognised diversity among students, but mainly based on students’ shortcomings and perceived problems. A minority of this 60% not only recognised but also understood diversity’s effect on student achievement. Teachers do not always translate this understanding into their teaching practice. They feel they lack the skills, knowledge or time to do so. Teachers seemingly translate their understanding of diversity into their didactic and pedagogical approaches only when these conditions are met.