Abstract:

Private tutoring has become a worldwide phenomenon alongside the formal education system since the early 21st century (e.g. Aurini et al., 2013; Lee, Park, & Lee, 2009; Mori and Baker, 2010). Students from different countries regularly turn to private tutors for paid extra classes and these services are necessary not only by low-performing students, but also by those whose academic achievements are high (Choi & Park, 2016). An awareness of the importance of the market for tutoring services for the educational system led to a multifaceted study of this phenomenon. However, the study of the effectiveness of lessons with tutors is of the greatest interest, since this direction is characterized by the greatest number of conflicting results. For example, in a number of studies, results confirm the positive effect of tutoring both on the students' academic achievement and on increasing their motivation for in-depth study of the subject (Guill and Bos, 2014; Rudolph, 2002). Nevertheless, the researchers also put forward the thesis that paid additional classes do not always bring the desired result, despite the willingness of families to invest in this type of education. These studies showed that there were no significant differences between students who did or did not attend with tutors (Paviot et al., 2005). the presence of minor effects only for a certain group of students - for example, for academically successful ones (Zakharov, Loyalka, 2016). Such different results could have been obtained due to the fact that there are no uniform criteria for assessing the quality of the work of tutors - this market is shady, and a tutor can be a person with any background, experience and qualifications.

An attempt was made to standardize quality on the part of one of the largest websites for the selection of tutors profi.ru. This site has developed certification of tutors who register on the site - An extensive standardized test, similar to the exams for which the teacher prepares (USE, GMAT). The testing system is built on the principles of computer adaptive testing, which allows the teacher to determine the teacher's level most accurately in a small number of steps. The opportunity to get a high mark due to memorized templates is excluded. This certification is voluntary for tutors.

This work aims to assess whether there is a significant effect on the choice of a tutor who has passed this certification. An analysis of the profiles of 13260 tutors in main school subjects from Moscow, Russia was conducted. One of the largest websites for finding tutoring services (profi.ru) was used as a data source. The results of the analysis showed that certified tutors charged a higher price for their services and had a higher rating made by students' assessment of tutors' work. This relationship is statistically significant. Accordingly, certified tutors who have confirmed the level of their expertise better meet the needs of students and provide a better educational service.

Keywords:

Private tutoring, certification.