# The Use of Educational Games in Programming Assignments: SQL Island as a Case Study
## 4 Results
### Student Performance  
According to students' responses in the questionnaire, 91% (\(N\) = 51) of them managed to finish the game, which means that they managed to write correctly all the SQL queries posed in the game. Of course, the students submitted the SQL statements they wrote for the queries, and they were corrected by the instructor, but this question was included as a means of checking the validity of the responses provided by the students to the questionnaire. Out of the five students that did not complete the game, two students correctly wrote 10 out of the 20 queries, and the other three students correctly wrote 15, 17, and 19 queries.  
In Table 1, information about the exercises of each assignment carried out during the semester is presented. It is clear that the results of the assignments cannot be directly compared since they refer to different programming concepts that might pose different difficulties to students. Moreover, in all the exercises--except for the one based on SQL Island--students do not receive immediate feedback while writing their code. The increased number of students that excelled in the SQL Island exercise might be attributed to the fact that serious/educational games increase students' motivation [1,2] and engagement [3], but also to the fact that the game provides immediate feedback to students' attempts and  
Figure 3: (a) Students’ non-digital game habits. (b) Students’ digital game habits.  
even hints, and this means that students are guided to correct their errors. The immediate feedback provided to students is considered important and can help them at the time of practicing and self-assessing their knowledge.  
Studying the duration of playing SQL Island in the context of the corresponding exercise can also provide some interesting conclusions. The results of the relevant question included in the questionnaire are presented in Table 2. An interesting observation is that although some students managed to write all the SQL queries correctly and finish the game in 23 min, there were four students that devoted from 2 to 5 h in order to finish the game. This is definitely a clear indication of having difficulties with SQL, but also of engagement and persistence due to the game environment. Moreover, it is quite certain that without the immediate feedback provided by the game, these students would not have managed to reach a completely correct solution. This might explain the increased percentage of students that achieved the optimal solution in this exercise.  
When studying the playing duration for the students that did not finish the game, we see that the average duration of game playing is 84 min, while for the students that finished the game, the average is 56 min. With the exception of one student that spent only 20 min in the game, the rest spent 70 (two students), 80 (one student), and 180 (one student) minutes. As was the case for the four students that finished the game after spending at least 2 h, the aforementioned four students (that spent more than one hour and despite this, they did not manage to finish the game) also faced difficulties with SQL. The time spent in the game is a clear indication of a long trial and error process. Taking into account that two students solved correctly half the queries and the other three were very close to completing the game, it is clear that even these students benefited from the game and managed to deal with their difficulties with SQL to a high degree through the immediate feedback and the hints provided by the game in real time.