Abstract:

The main goal of the Bebras challenge is to encourage children to learn informatics concepts, and to support development of computational thinking. Tests and quizzes are an effective way of learning if students in a relatively short time get feedback and have opportunity to learn the right solutions. The Bebras contest meets these conditions. Participants know their score immediately and sample solutions with explanations are ready in few weeks. The online archive of tasks from previous years also contributes to effective preparation of participants.

While the competition has the ambition to reach all students, the tasks are generally not accessible to blind students. Blind students work with computer using a screen reader and the only information they can work with is text and sound. They cannot use a mouse to control the computer, but they enter input only using the keyboard. As regards the Bebras contest, they cannot participate at all, despite of the fact that they achieve comparable results with able bodied students in computer science classes. Bebras tasks contain elements inaccessible to the blind, such as images, colours, interactive features, and so on. To enable blind students to enter the competition, it is necessary to make some changes of rules. Suggested adaptations of rules and tasks for blind students we will describe in our paper. We also provide an overview of several studies aimed at analysing the difficulty of Bebras tasks for able-bodied students.

Bebras contest takes place in almost sixty countries all over the world, but Slovakia is the only country that allows blind students to participate in the competition without the assistance of a sighted person. This is thanks to special categories for the blind. We offer a separate category for lower secondary blind students (aged 11 to 15) and another one for upper secondary blind students (aged 15 to 18). In our paper we will focus on the category of upper secondary blind students, because we have covered the category of the lower secondary blind students in other papers. The category for upper secondary blind students was offered for the first time in 2017.

During the existence of this category, we have adapted 54 tasks. We have noticed that the real difficulty of the tasks was different as expected. In order, to better estimate the difficulty of the tasks in the future, we decided to observe the influence of some factors on the difficulty of the tasks.

We performed a detailed analysis of all tasks aimed at specifying the inputs and required procedures needed to solve tasks. We also monitored the real difficulty of the tasks and compared it with the expected difficulty.

Primarily we were looking for answers to the following research questions.
Q1: What is the relationship between task's affiliation to the thematic area and the difficulty of the task?
Q2: What is the relationship between the required skills and difficulty of the task?
We used a case study research strategy. The 54 tasks used in the competition for the blind were observed cases.

In our paper, we present our findings and compare them with those of other authors dealing with task difficulty for intact participants.

Keywords:

Blind students, informatics contest, difficulty level, inclusion, computing education.