AbstractDetermining the learning quality and the role of measurement and evaluation are accepted as part of the duties and responsibilities of teachers and operators in structured teaching programs. This qualitative case study research examined teacher candidates' conceptual understanding of the reasons for measurement and evaluation and for determining of the learning change to ascertain if trained teacher candidates met the required expectations. The study participants were determined using criteria sampling and consisted of 101 science teacher candidates. The data was collected using open ended questions, which were analyzed using content analysis. The research found that the teacher candidates' conceptual understanding as to the reasons for evaluation and determining the learning change were inadequate. It was found that the participants were unable to relate the measurement and evaluation purposes with learning change, arid that the understanding of the measurement and evaluation concepts aimed at determining the need for learning change did not coincide. The data suggested that there could be teacher training insufficiencies arid that the duties and responsi bititles of the new teaching programs encumbered the teachers. In this context, it was suggested that determ ini ng the learning changes by measurement and evaluation practices be emphasized during teacher training.KeywordsDetermining the Learning Change, Teacher Candidates, Measurement, Evaluation, Conceptual Understanding.Over the last five years the teaching programs in our country, which had been developed within the frame of the European Union adaptation standards, have been restructured with regard to learning areas and approaches. Newer teaching programs, therefore, have improved natures/structures (Kurnaz & Cepni, 2012; Milli Egitim Bakanligi [MEB], 2007; Ustun, Eryilmaz, & Gulyurdu, 2008). Therefore, teachers and the operators of teaching programs have new important responsibilities with regards to the areas of learning and approaches to the program (Ates et al., 2009; Gunes & Tasar, 2006; Serin & Kanli, 2008). This implies that teachers are expected to assimilate these renewed learning areas and approaches into their teaching, such as the constructivist learning approach which requires that learners take responsibility for their own learning progress while the teachers act as facilitators or guides (Cobern, 1993; Karamustafaoglu, Costu, & Ayas, 2005; Kurnaz & Calik, 2008, 2009; Mathews, 2000; Osborne & Wittrock, 1983).For science and technology teaching programs, teachers are required to carry out diagnostic, formative, and summative measurement and evaluation (Kumaz & Cepni, 2012). Therefore, there needs to be a change in the way teachers perceive the measurement and evaluation process in parallel with the new teaching programs, a process which is clearly stated in the teaching programs (see also MEB, 2006, 2013). The key features of the diagnostic, formative, and summative assessments are shown in Table 1.As shown in Figure 1, a teacher needs to first conduct a diagnostic assessment to determine a student's present knowledge. From the data obtained, a formative assessment is conducted to enable a deepening of the learning. Finally, a summative assessment is conducted to determine the student's acquisition, recognize the learning change, and identify learning gaps. What is new here is the need for the diagnostic assessment at the start of the learning process and determining the learning changes. As stated above, the diagnostic assessment is related to understanding the extent of a student's prior knowledge.According to Hailikari (2009), prior knowledge is used for (I) determining the student's level, (II) determining the class aims, and (III) designing the student learning environment. In recent research, it has been observed that students' prior knowledge level should be considered for determining learning change (Hake, 2002a, 2002b; Ladd & Walsh, 2012; Meltzer, 2002; Thompson, 2008; Zeilik, 2012). …