Teachers’ understanding of assessment.

Teachers’ assessment knowledge, AK, is the knowledge and understanding teachers have about assessment, its value, its types, and its applications for evaluating students’ learning outcomes. Assessment carried out in the classroom is designed both to help teachers determine what and how well students learn (assessment of learning) and to improve students’ learning (assessment for learning) (Birenbaum et al. 2006). These two possible objectives of assessment are also referred to as summative and formative assessment, respectively. Most of the students’ assessment mode and content are determined by their science teachers – the assessment agents. They choose what, how, and when to assess their students. Since new and challenging reforms in science education require teachers to teach for meaningful learning, science teachers are required to cope with new teaching methods and assessment that are aligned with these new methods (Abell 2007; Magnusson et al. 1999).