## 2 Related Works
The analysis of the impact of time spent on interaction within the educational context is not strange as the international recommendations also mention time as an essential aspect of accessibility. For example, two guidelines of the WCAG's 3.0 recommendation [24] emphasized the time factor as an important component in accessibility: guideline 1.2 \"Time-based Media: provide alternatives for time-based media\" and guideline 2.2 \"Enough time: provide users enough time to read and use content\". This recommendation directly stresses the need to extend the slot of time in educational activities allocated to people with different capabilities. The literature has considered the allocation of time in accessible learning environments. [PERSON] et al. [32] confirmed problems related to respecting accessibility guidelines such as allocating enough time to read and use content, something especially critical for students with different capabilities, e.g., blind users, low-vision users, deaf users, or users with cognitive or language limitations. A work in the e-learning context for visually impaired students [36] and another one on the use of extended time [37] highlighted the adaptation of reading time as a key factor for task completion by the different types of students. [PERSON] and [PERSON] [15] measured the time spent completing different online learning tasks by 10 blind participants and 10 sighted participants and determined the ratio of extra time required by blind students compared to sighted ones. [PERSON] et al. [38] requested a holistic approach for multimedia to achieve more accessible learning environments and confirmed that time is a characteristic needed to be considered from the beginning. Another study [39] presented the action plan of 52 European universities to integrate students with different capabilities and highlighted modifications of the predetermined timeframe of curricular objectives as part of the teaching and evaluation activities in academic programs. Different studies went further into the analysis of the effects of lack of time on the speed of reading [40] but also on the accuracy of results and comprehension [41; 42; 43]. These works confirmed that providing enough time to students with different capabilities enables them to achieve an equivalent performance to that of students with no disability. For example, an analysis of 299 students compared the reading and comprehension rates between visually impaired and normally sighted school children [43]. Results showed a statistical difference for the visually impaired students, concluding that the blind students took approximately two to three times more time to complete the tasks than the sighted learners: increasing the allocated time depending on the personal characteristics of each student works, although this is very difficult to implement. Another study [40] established a slightly shorter time to be added: between 1.5 and 2 times longer than what sighted students need. Some countries have policies for deciding how much additional time should be allowed for students with different capabilities, but it is usually the same fixed amount for all types of disabilities [44]. [PERSON] [45] also studied the advantages and disadvantages of the addition of fixed extra time for reading, completing tasks, and taking tests to solve some accessibility problems; the final recommendation was using time adapted to each individual depending on their level of visual impairment and their experience in using the adapted format. The big problem is how to estimate the recommended extra time required or at least how to provide guidelines to teachers to decide the amount of extra time required. Some studies referring to time spent on learning activities provide some indications, but they are not conclusive, as they were not supported by relevant experimentation. [PERSON] and [PERSON] [46] established that the time allocated to users with low vision should be 1.5 times longer than that allocated to sighted ones.