Archive for March, 2012
Spring has sprung and the warmer temps have caught everyone off guard. As you are well aware, many of the General Classrooms are much warmer than normal, which has led to issues with the mediation equipment (primarily projectors). As a safe guard, the projectors may shut down to save the unit from overheating and damage. Please feel free to continue to contact us directly (419-530-2656) if you have any problems. Facilities is very aware of the temperature issues and continues to work on those for ALL of us.
Assistant Director of Classroom Support Services
Several instructors have just brought to our attention the fact that when they calculate students’ grade averages using both a “Total Column” and and “Average Column” (when both are set to display a percentage), the results are numerically different.
As an example, let’s say that you have two quizzes worth a maximum of 10 points each and two tests worth 100 points each. Let’s also assume that a particular student’s scores on these 4 items were 9, 8, 80, 70.
There are two ways to calculate a grade “average” in Blackboard depending on your intention:
(1) If you use a “Total Column” and set the Primary Display to Percentage–this will take the sum of the the total points earned and divide it by the sum of the total points possible.
The result for our example above would be (9 + 8 + 80 + 70)/(10 + 10 + 100 + 100) = 167/220 = 0.7591 = 75.91%
(2) If you use an “Average Column” with the Primary Display set to Percentage–this will take the total number of percentage points for each column, add them up and then divide by the total number of columns.
The result, once again using our original data, would be (90% + 80% + 80% +70%)/4 = 320%/4 = 80%
(In other words, this options treats each assessment as being of equal importance or weight regardless of how many total points the original assessment was worth.)
Whether you choose to use a “Total Column” or an “Average Column” to calculate your students’ “average” grades is strictly up to you as long as you are aware that your results will depend upon which type of column you choose to use.
Another potential source of confusion in using calculated columns (including Total or Average) involves deciding whether or not to check the radio button next to “Calculate as Running Total” during column setup. If the running total option is selected, any assignment or test for which a grade has not been entered will not be used in the calculation. You can, however, avoid this problem by either not checking this option or enter a “0” for any missed assignments or tests to force the system to include this grade in the calculation.
Hopefully, this will clarify how Blackboard calculates a grade “average” depending upon which type of column you choose. If you have any question or need any assistance with this, please contact UTLV@utoledo.edu or call 419-530-8835 for assistance.