Know how your students are doing and activities are performing.
Steps in Snap: Admin > X-Ray > Gradebook
Steps in other themes: Turn editing on > Administration > Course administration > X-Ray > Gradebook
X-Ray extracts and analyzes information from the gradebook to keep you informed on how your students are doing. This gradebook report tells you the following.
- Student grades: This table shows you how well students are doing on the graded items in the course.
- Distribution of grades: This graph shows how the scores for the graded item groups are distributed over your students.
- Summary of graded items: This table shows how students have done on average on each graded item.
- Distribution of scores: This box plot shows the distribution of student scores on a graded item.
- Automatic discussion forum grading versus Course grade: This graph shows the relationship between the X-Ray grades for the discussion and the course grades.
- Comparison of scores: This heat map shows how each student did on a graded item compared to the rest of the class.
Grades for all graded items available in the course are analyzed and a percentage is created for certain item categories.
Point scales and grading policies can be different between graded items. Percentages are created to give a consistent overview of how a student is doing.
Distribution of grades
This graph shows how the scores for the categories are distributed over your students.
The peak shows what the majority of students are getting.
Normal distribution looks like a bell curve. Bell shaped distribution patterns could indicate that there was no bias or inconsistencies.
Different distribution patterns may indicate significant differences in the difficulty level of the graded item categories.
Summary of Graded Items
This table shows how students have done on average on each graded item. It also shows you the relationship of this graded item to the student's course grades so far. Low percentages (or even negative ones) could indicate that students performed very differently on this graded item than they normally do.
At a quick glance you can see the following for each graded item.
- Category of the graded item
- Number of students who participated in this graded item
- Average score in percentages
- Relationship between the scores on the graded item and the course grades to date
Distribution of Scores
A refined box plot is used to show the distribution of student scores on a graded item.
In a box plot everything in the visual works together to give you valuable information about your graded item. It can show you how students do overall on a graded item. It can also help you identify graded items that may be too easy or too challenging.
So how do you read it?
Let's break it down. There are four elements you need to know.
- Boxes represent graded items.
- A thick horizontal line shows the average of the scores.
- Dots are used for student scores.
- Vertical lines show score ranges.
A box is used to represent your graded item. This includes the vertical lines above and below it, called whiskers.
The location of the box on the graph shows the range of scores received on this graded item. Boxes higher on a graph indicate higher scores overall.
A thick horizontal line is used to show you the average score on the graded item.
Dots are student scores.
- Dots higher on the graph indicate higher scores.
- Dots above or below the average horizontal line are scores above or below the class average on that graded item.
If there is only one score for a graded item, you will see a single dot and the average line. You will not see a box or whiskers.
There are four vertical lines.
- The whisker on the top of the box. This represents the top 25% of scores on the graded item.
- The side of the box above the average line. This is the 25% above average.
- The side of the box below the average line. This is the 25% below average.
- The whisker on the bottom of the box. This is the bottom 25%.
You may notice that even though each section is 25% of the scores they are not the same in size. Longer vertical lines means scores are spread out further in that range. For example: You may have two scores in the below average section that are 2 points apart. The below average will be shorter than another section that has scores that are 10 points apart.
Putting It Together
This example shows a box plot with seven graded items included.
- Exercise 7 shows long vertical lines. The scores are spread out from 0 to 100%. Some students did very well, and some very poor.
- Exercise 2 and 4 seems to have been too difficult. The average lines are low compared to the other graded items.
- The box for Exercise 2 shows short vertical lines. Most students scored similarly.
Assigned Discussion Forum Grading Versus Course Grade
This graph shows a comparison of the automatic X-Ray grading on the basis of the quality of the discussion posts to course grades.
The black line shows the expected relationship between the X-Ray discussion grading and course grades.
The shaded area is the confidence interval for the expected relationship. Confidence intervals provide a range for the expected relationship that accounts for miscalculations or change of circumstances. Narrow confidence intervals indicate high confidence in the expected relationship.
Each dot in this graph represents a student. Typically, dots should stay within the expected relationship range. Dots outside the expected relationship range may indicate inconsistencies. This could be due to any number of reasons including students performing better than expected in graded items than in discussion contributions or the other way around.
Comparison of Scores
This heat map shows how each student did on a graded item compared to the rest of the class.
Colors range from red, orange, yellow, to green and indicate scores from low to high.
If you have too many of one shade it may indicate that the graded item is too easy or too difficult.