Nazarbayev Intellectual School (further referred to as NIS) began collaborative work with Cambridge International Examination experts in September 2013 to develop an Integrated Criteria-Based Assessment Model (ICBAM) assessment system. During the 2016-2017 academic year, this assessment was replaced by a Criteria-Based Assessment (CBA) system. There has been much discussion on the effectiveness of both assessment models for the NIS education system. For example, Torrance (2007) investigated "whether or not the use of different assessment methods makes a difference to learner achievement and progress in the learning and skills sector" (p.283). In research, clarity in assessment processes and criteria has underpinned the widespread use of coaching, practice, and the provision of formative feedback to boost achievement.
The current research aims to compare the effectiveness of CBA and ICBAM assessment models and find ways to increase students' academic achievement.
The research questions:
- What is the impact of CBA and ICBAM on student results (academic achievement)?
- What are the attitudes of students towards CBA?
- What are the students' and teachers' recommendations regarding the CBA?

A mixed research design was used for this research: the quantitative method was used to compare two assessment models, ICBAM and CBA. The researchers opted for the qualitative approach to collect data on teachers` recommendations regarding ICBAM and CBA. In order to identify which of the two models is more effective, descriptive statistics (representation and summary of data) in a software Statistical Package for the Social Sciences (SPSS) and a hypothesis test were carried out using their summative scores with a null hypothesis that assumed an equal score. The alternative hypothesis assumed ICBAM score mean to be more than CBA when both models were used. To prove or reject the established null hypothesis test, the mathematical calculation of testing was used, the difference between means of IMCBA and CBA are normally distributed. The participant in the research were two groups of students. The sampling strategy was purposeful. Focus group 1 consisted of the 2016-2017 8th-grade students; the second group included 2017-2018 8th-grade students of NIS Aktobe. These students were taught the same curriculum but with different assessment models. 138 students of group 1were assessed by the integrated educational program and were assessed with the Integrated Criteria-Based Assessment Model (ICBAM) in the 2016-2017 academic year. Group 2 included 170 students of grade 8 who experienced both CBA and ICBM assessment systems. To answer this question and support the hypothesis test, a survey was carried out among grade 10 students at NIS Aktobe, who had been assessed using both models. While studying in grades 7 and 8, the students were evaluated by the ICBAM system. Then in grades 9-10, they were assessed through the CBA. Finally, grade 10 students were asked to participate in an online survey. Further, 18 Maths teachers with experience working with both models were interviewed. Their responses were audio-recorded and analyzed.

Findings Question 1: The analysis of the findings suggests that the mean score of summative assessments of the ICBAM outweighs the CBA assessment. The new assessment system decreases a student's academic achievement compared to the old one. Question 2: According to the survey results, many respondents felt they received more support from their subject teachers in the ICBAM system. Question 3: The findings obtained through individual face-to-face interviews suggest that ICBAM supports students' assessment during the learning process more than CBA. In addition, the analysis revealed that the ICBAM assessment system was learner-friendly, whereas the CBA assessment system did not enable students to polish their assessed skills. Another noticeable finding relates to teacher workload. The majority of interview participants reported that ICBAM system created a heavier workload for the teachers. Since they were to re-teach and re-assess students multiple times, collecting new tasks and taking additional one-on-one time was considered time-consuming for both students and the faculty. Torrance (2007) argues that assessment has to move from 'assessment of learning' to 'assessment for learning', where assessment procedures and practices dominate the learning experience, and 'criteria compliance' replaces 'learning'. The research found that students require time to revise the learning objectives and master their skills, which could be achieved by effective feedback, linking the assessed content to their progression in the skills, they acquired according to the criteria-based rubric.

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