With advancing technology, the need to train individuals who can both use and create with it has grown. Computational thinking (CT), encompassing problem-solving, analytical thinking, and solution generation, is increasingly vital. To teach and assess these skills, the mobile-compatible system MoBiForum was proposed for middle school students. It allows students to earn points by adding methods linked to CT sub-skills, using content in text, audio, or image formats. The process concludes with a mind map creation, evaluated by teachers through system-generated reports.

A case study method was used to determine the design requirements for this system. In the first phase, semi-structured interviews were conducted with 5 computer science teachers via a 9-question form. The data obtained from the teachers were analysed by creating a theme-code table. In the second phase, focus group discussions were conducted with 20 students at the 5th grade level, by using a 13-question form containing software samples and visuals. The students’ data was analysed in the same way of that of teachers. In the final phase, problem scenarios based on real-life and programming topics were prepared for the activities in the MoBiForum system. These problem scenarios were designed to include sub-dimensions of CT: decomposition, pattern recognition, abstraction, and algorithm creation. The scenarios were revised regarding the expert opinions gathered via a form used for three experts in the field of Computer Education and Instructional Technology.

The theme-code tables have guided the visual design and content development process of MoBiForum. In teacher interviews, 6 themes such as “Learning Objectives” and “Technological Tools”, and 11 codes for all the themes were identified. For example, “Problem-Solving Suggestions”, “Problem Analysis”, and “Algorithm Development” are the codes under “Learning Objectives”. In the student interviews, 5 themes such as “Colour” and “Font”, and 13 codes in total were obtained. For example, “Favourite Colour” and “Figure-Ground Relationship” are under the “Colour” theme.

Based on the teachers’ and students’ feedback, content and user interface design of the system was prepared. Blue and pink colours, contrasting colour combinations, circular or rounded rectangular buttons, and "Gorgeous" -a bold and stylish serif font- were used according to students’ feedback. For example, when a student mentioned blue as their favourite colour for the character since it was clearly understandable due to its contrast background colour. Additionally, a customizable "brain" character was added to the design, considering the students' interest in characters. Besides, regarding the teachers’ feedback, the importance of providing real-life examples was considered in the content development process of the system.

As a result, MoBiForum is proposed to be developed based on the feedback that was exemplified above. It is predicted that the proposed system design will be effective in developing CT skills of middle school students, and further research should be conducted to test its effectiveness and improve the system.

Acknowledgement:
This study has been supported under the “TÜBİTAK 1001-Scientific and Technological Research Projects Support Program.”

Keywords: Computational Thinking, Knowledge Building Systems, Computer Science Education.