The selection of cloud services for ER-diagrams construction in IT specialists databases teaching Tetiana A. Vakaliuk1,4, Olha V. Korotun1 and Serhiy O. Semerikov2,3,4,5 1Zhytomyr Polytechnic State University, 103 Chudnivska Str., Zhytomyr, 10005, Ukraine 2Kryvyi Rih State Pedagogical University, 54 Gagarin Ave., Kryvyi Rih, 50086, Ukraine 3Kryvyi Rih National University, 11 Vitalii Matusevych Str., Kryvyi Rih, 50027, Ukraine 4Institute of Information Technologies and Learning Tools of the NAES of Ukraine, 9 M. Berlynskoho Str., Kyiv, 04060, Ukraine 5University of Educational Management, 52-A Sichovykh Striltsiv Str., Kyiv, 04053, Ukraine Abstract One of the main aspects of studying databases in higher education institutions by future IT specialists is database design and software product development. This, in turn, is the most important problem of the developer’s interaction with the customer. To facilitate the process of database design, ER-diagrams are used, which are based on the concepts of “Entity” and “Relationship”. An ER diagram allows you to present a database in the form of visual graphical objects that define a specific subject area. The article considers the available cloud services for the construction of ER-diagrams for learning databases of future IT specialists and their selection the method expert evaluation. For this purpose, the criteria and indicators for the selection of cloud services for the construction of ER-diagrams of databases by future information technology specialists have been determined. As a result, it was found that the cloud services Dbdesigner.net and Lucidchart are the most convenient to learn. It is determined that for a teacher of a higher education institution the use of cloud services is an opportunity to use licensed software in education without additional costs. Keywords selection, cloud services, ER-diagrams, databases, future specialists in information technology, future IT specialists 1. Introduction One of the main aspects of studying the discipline “Databases” in higher education institutions by future information technology specialists is database design and soft-ware product development, which in turn is the most important problem of interaction between the developer and the customer. While studying it, students should realize that the task of the developer is to reproduce the wishes of the customer as accurately as possible by developing a database management CTE 2020: 8th Workshop on Cloud Technologies in Education, December 18, 2020, Kryvyi Rih, Ukraine " [email protected] (T. A. Vakaliuk); [email protected] (O. V. Korotun); [email protected] (S. O. Semerikov) ~ https://ztu.edu.ua/ua/structure/faculties/fikt/teachers_kpzot.php (T. A. Vakaliuk); https://cs.ztu.edu.ua/our-team/ (O. V. Korotun); https://kdpu.edu.ua/semerikov (S. O. Semerikov) 0000-0001-6825-4697 (T. A. Vakaliuk); 0000-0003-2240-7891 (O. V. Korotun); 0000-0003-0789-0272 (S. O. Semerikov) © 2020 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). CEUR http://ceur-ws.org Workshop ISSN 1613-!!" Proceedings CEUR Workshop Proceedings (CEUR-WS.org) 384 software product. Therefore, the main problem that future IT professionals need to learn to solve is the correct construction of a database diagram. To do this, future developers must study in detail the subject area of the database and make the requirements of the customer. The result of this work should be a database that is clear and that most accurately reflects the problem to be solved and does not contain redundant data. To facilitate the database design process, ER charts are used, which are based on the concepts of “Entity” and “Relationship”. ER diagram allows you to present a data-base in the form of visual graphical objects that define a specific subject area. 1.1. Analysis of recent research and publications Many scientific papers are devoted to database theory (DB), database normalization processes, database design methodology, database architecture, consideration and description of modern DBMS, SQL query language, etc. Dowming Yeh and Yuwen Li and William Chu investigated the possibilities of extracting the diagram of the relationship of the entity from the table of an outdated database [1].The author’s proposed new approach uses the display forms, table schema, and instances as a database reverse engineering input [1]. Paul Schmieder, Beryl Plimmer, Gillian Dobbie consider the possibilities of computer tools for building sketches for informal sketching and automatic conversion into official submissions [2]. At the same time, the authors consider the InkKit charting tool with domain semantics for successful recognition and automatic conversion of entity-relationship diagrams [2]. Another group of authors (P. S. Dhabe, M. S. Patwardhan, Asavari A. Deshpande, M. L. Dhore, B.V. Barbadekar and H. K. Abhyankar) considered the Articulated Entity-Relationship, which was considered an extension of the Entity-Relationship diagram. The researchers considered these types of diagrams as an integral part to fully automate normalization in the case of placing information about functional dependence [3]. A group of authors (Xiong Jing, Liu Yong-ge, Gao Feng, Wang Ji-peng) analyzed the similarities between the model of entity relationships and the model RDF (model for representing named properties and property values), also, proposed ideas and processes of transformation. The researchers also implemented the Oracle Bone Inscriptions ontology using a transformation method that requires manual intervention during the transformation process [4]. Other scientists (Alexander L. Hayes, Mayukh Das, Phillip Odom and Sriraam Natarajan) have proposed a convenient automatic construction of background knowledge by constructing a mode from ER diagrams. The authors have developed a graphical user interface that allows a domain expert to interact with the system using entity relationship diagrams used to build modes for the learning system [5]. Cloud technology has been studied by many scientists [6, 7, 8, 9, 10, 11, 12]. In particular, Albert A. Azaryan, Kateryna P. Osadcha, Viacheslav V. Osadchyi, Svitlana V. Symonenko, Svitlana O. Sysoieva, investigated cloud technologies for enhancing communication of IT professionals [13]. Nataliya O. Kushnir, Viacheslav V. Osadchyi, Nataliia V. Valko considered cloud technologies for STEM education [14], Svitlana L. Proskura and Svitlana H. Lytvynova considered the approaches to Web-based education of computer science bachelors in higher education institutions [15]. Oksana M. Markova, Serhiy O. Semerikov, Andrii M. Striuk, Hanna 385 M. Shalatska, Pavlo P. Nechypurenko and Vitaliy V. Tron investigated the implementation of cloud service models in training of future information technology specialists [9]. However, the question of appropriate selection of cloud services for the construction of ER-diagrams for training databases of future information technology professionals has not been explored, so this will be the purpose of this article. 2. Methods of the study Methods of analysis and generalization were used to determine the criteria and indicators for the selection of cloud services. To determine the most important cloud services for the construction of ER-diagrams of databases that can be used in the educational process of future specialists in information technology, the method of expert evaluation was used [16, 17]. Experts were involved in this method twice. The first stage of involving experts was to determine the most effective cloud services for building ER-diagrams of databases. At this stage, experts and teachers of higher education institutions were involved as experts, which in one way or another are related to the database learning of IT specialists (17 people). For consideration by ranking experts, 12 different cloud services were proposed to build ER-diagrams of databases that can be used in the training of databases of future information technology professionals. Experts were offered a scoring system [16, 17], according to which for N services the value of N is given to the most important in use, 1 – to the least important. The main parameter for assessing significance is its total rank S, which is calculated by the formula [16, 17]: m X Sj = Ri;j; (1) i=1 where Sj is the total rank of the j-th indicator; j = 1; 2; 3; :::; n; n is the number of indicators; m – number of experts; Ri;j – the rank of the j-th indicator, determined by the i-th expert. Besides, to determine the level of agreement between experts, it is necessary to calculate the Kendell concordance coefficient W [16, 17], which determines whether such total ranks are objective, and it is calculated by the formula: S(d2) 12 · S(d2) W = 2 = 2 3 (2) Smax(d ) m (n − n) where: dj = Sj − 0:5 · m(n + 1); (3) n 2 X 2 S(d ) = dj ; (4) j=1 386 After the calculations, if the value obtained differs significantly from zero, it indicates that there is an objective agreement between the experts and therefore the total rankings are quite objective. The second stage of involving experts was to select the most important cloud services for building ER-diagrams of databases according to certain criteria and indicators. At this stage, 15 respondents were involved to test the manifestation of each of these criteria for each of the selected cloud services to build ER-diagrams of databases. At this stage, respondents were asked to evaluate all indicators for each criterion. Evaluation of indicators was proposed to be carried out on a well-known scale [16, 17] from 0 to 3. As a result, the indicator was considered positive if the value of the arithmetic mean of its parameters was not less than 1.5. The degree of manifestation of the criterion was determined by the following scale: if 76% – 100% of its indicators are positive, the criterion is characterized by the high expression, 56% – 75% – sufficient manifestation, 50% – 55% – critical manifestation, if less than 50%ofits indicators were positive – the criterion is considered insufficiently manifested. 3. Results To build an ER-diagram of the database at the logical and conceptual levels, we propose to use cloud services.