https://orcid.org/0000-0001-5903-8829
Figures & data
Figure 1. Example dialog in the control group when starting the Alexa skill for the first time.
Figure 2. The flowchart illustrates the interaction with the Alexa skill in the control group.
Figure 3. General flowchart illustrates the interaction with the Alexa skill in the experimental groups (achievements and leaderboard).
Figure 4. Example of a dialog in which the user calls up the leaderboard.
Figure 5. Example dialog for a user who receives an achievement and starts a challenge.
Table 1. List of all achievements with their title and description.
Table 2. Mean, standard derivation, and median of the sum of processed vocabulary, correct answers, and time in seconds per user.
Table 3. Mean, standard derivation, and median ratio of correct vocabulary to the sum of answered vocabulary.