## 3 Materials and Methods  
### Participants and Cohorts  
To analyze the platform's implementation at schools, data were collected from three pilot groups in regard to their first year of use. Groups belong to different regions from the Spanish territory. Smile and Learn has signed agreements with various regions of Spain to implement digital material in schools with electronic devices. These schools are selected by said regions, or through registration processes regulated by the educational delegations in charge. A common characteristic of these schools is that they are public schools. With the bilingual model (Spanish and English) this material helps to have bilingual content to use. With the same idea, the implementation of the digital material agreement established that this material provided to schools is free and complemented with teachers training by the education team. In so doing, these schools have free access to all the content and functionalities of the educational intelligent platform. In the case of this study, the pilots analyzed in their first year of implementation in public schools have Spanish as their official language, without a second official language in these regions. Therefore, the use of the implemented digital material has been carried out mainly in Spanish, with the exceptions of classes in the bilingual plans (which also used English), and the subject English. Figure 2: Screenshot of the platform showing management resources for a group of children. Multiple options are given, as seeing the progress and usage time per activity, personalizing profiles, organizing the activities that must be done, adding passwords, and so forth. The two following criteria were established in order to build the working database for admissions into groups, in the aim of avoiding noise for further analyses. (1) The first criterion attunes inclusion parameters, assigning the platform to be used in schools for primary education and excluding those with children aged 3-6--this criterion was set to facilitate the comparison between curricular contents and the catalogue of educational contents elaborated for the platform. (2) The second criterion helps database systematization, disposing all the groups to include the name of the class (e.g., '1C') and the age of its students, excluding random names or nicknames for the classes. The selection of these groups is related as follows: first grade (aged 6-7), second grade (7-8), third grade (8-9), fourth grade (9-10), fifth grade (10-11), and sixth grade (11-12). Those groups can be organized as 1 st Cycle (groups 1 st, 2 nd, and 3 rd) or 2 nd Cycle (groups 4 th, 5 th, and 6 th) of primary education. Groups working with children with special needs were classified as Special Needs group properly. Regarding cohorts, this study analyzes the use of the platform in three pilot groups composed by public schools from different locations where the implementation was done in different moments of the academic course 2018-2019. (1) The first group covers 49 schools, with 238 classes (18 with special needs; 134 of 1 st Cycle; 86 of 2 nd Cycle). The training period for this group was from January to February of 2018, and the timeframe selected for assessing implementation and usage was between March of 2018 and June of 2019. (2) The second group is composed by 29 schools with 251 classes (16 classified with special needs; 117 of 1 st Cycle; 118 of 2 nd Cycle). The training period in this region was from May to June 2018, and the timeframe of usage spans from September of 2018 to June of 2019. (3) The third pilot group has 26 schools with 122 classes (9 with special needs; 60 of 1 st Cycle; 53 of 2 nd Cycle). The training was scheduled in October of 2018, with a timeframe of usage from November of 2018 to June of 2019. Smile and Learn's platform was used to collect this information from users via a learning analytics system.