A questionnaire was given twice to 47 students to test their historical knowledge. In the first administration, most students scored between 11-15 mistakes with 47%. When taken the second time, most students scored between 6-10 mistakes with 40%, showing an improvement in historical knowledge. Specifically, more students scored between 1-5 mistakes (28% vs 4%) and between 6-10 mistakes (40% vs 13%) the second time. Fewer students scored between 11-15 mistakes (15% vs 47%) and 16-20 mistakes (17% vs 32%) the second time. No students scored perfectly or between 21-25 mistakes on either administration.

1. First questionnaire (first time)
0% 4%
13%
47%
32%
4%
0 mistakes
1-5 err
6-10 err
11-15 err
16-20 err
21-25 err
First questionnaire (second time)
We have given the questionnaire to 47 students.
The first time:
0% of them made 0 mistakes,
4% made from 1 to 5 mistakes,
13% of them made from 6 to 10 mistakes,
47% of them made from 11 to 15 mistakes,
32% of them made from 16 to 20 mistakes,
4% of our students made from 21 to 25 mistakes.
The second time:
0% of our students made 0 mistakes and from 21 to 25 mistakes,
28% of them made from 1 to 5 mistakes,
40% of them made from 6 to 10 mistakes,
15% of them made from 11 to 15 mistakes,
0%
28%
40%
15%
17%
0 mistakes
1-5 err
6-10 err
11-15 err
16-20 err

2. 17% of them made from 16 to 20 mistakes.
We can say that they improved their historical knowledge, in fact:
- while the first time only 4% of them made from 1 to 5 mistakes, the second time 28% made that
result,
- while the first time 13% of the students made from 6 to 10 mistakes, the second time 40%
obtained that result,
- while the first time 47% of our students made from 11 to 15 mistakes, the second time 15% of
them had that result,
- while the first time 32% of them made from 16 to 20 mistakes, the second time 15% of our
students obtained that result,
- while the first time 4% of our students made from 21 to 25 mistakes, the second time 0% of them
made that result.
Both the first and the second time 0% of our students made 0 mistakes.