The article demonstrates some of the results identified in a comprehensive study of the assessment process for certification of training courses. The study focuses on the attitude of the course participants towards the assessment, based on which recommendations were developed to improve the effectiveness of the assessment. Based on the views of the course participants who passed the assessment procedures, the impact and opportunities of assessment to improve learning outcomes are discussed. As part of the study, a Likert-scale survey questionnaire was taken from 2445 course participants who were assessed on training programs in different regions of the Republic of Kazakhstan from 2012 to 2020. According to the results of the survey, the explanatory statistical analysis showed that the majority of course participants experienced a positive effect of the assessment. Based on the parametric-correlation analysis, cognitive-action and emotional-motivational components were identified as factors influencing the attitude of course participants towards the assessment, and the issues of concern to the course participants in terms of the assessment process are explained.   Keywords: Teacher training courses, certification, assessment, assessment tools, objectivity, cognitive-action, emotional-motivational