Creating a Calculated Column

There are four types of Calculated Columns: Average Column, Maximum/Minimum Column, Total Column, and Weighted Column. Each type of column can be used to either singularly or in combination with other Calculated Grade Columns to tally and summarize the scores from selected columns.

  • An Average Column calculates and displays the "mean percentage correct" for a selected number of Columns. Columns with text as the primary display cannot be used in this calculation. (Please see the warning below before using this type of column.)
  • A Minimum/Maximum Column calculates either the minimum or maximum grade for a selected number of Columns. Columns with text as the primary display cannot be displayed as a minimum or maximum grade.
  • A Total Column simply sums the total points for a number of Columns related to the total number of points allowed. Total Columns are useful for generating a final score. Columns with text as the primary display cannot be totaled. Total Columns can be set to calculate a total for all selected columns (including those for which no score has been recored or graded--using a "0"), or to calculate a Running Total which includes only those columns for which a score has been entered either manually or automatically. Columns with a blank score are skipped for that particular student and thus each student may have a unique number of possible points.

    Note: A Total Column is included included in the Grade Center as one of the default columns. This column normally cannot be deleted, but it can be hidden from both the instructor and students.
  • A Weighted Column calculates and displays a grade based for a selected number of Columns based upon each column's respective worth of the total grade. Columns with text as the primary display cannot be displayed as a weighted grade. Each selected Grade Column or Category of columns must be assigned a percentage of the total score. You are also given the option of dropping the a specified number of the highest or lowest grade in a particular category.

 

Warning: Using an Average Calculated Column can produce unintended results

Choose carefully between a Total and an Average calculated column when summarizing a students scores. The Average calculated column in the Grade Center calculates an "average" that is different than what many Instructors and students expect.

An Average calculated column actually calculates the "mean percentage correct". That is, it takes the total number of percentage points awarded per column, adds them up, then divides by the number of columns.  While the "mean percentage correct" can be a helpful calculation, this is not what most people think of when they want an "average."

When most people want an "average," what they really want is the total number of points divided by the total number of possible points. To get that in Blackboard, you use a Total calculated column, displayed as a percentage.  This will provide an accurate average in the most basic sense.

In other words, unless you specifically want a "mean percentage correct" for a set of scores, DO NOT use the Average calculated column.  The Total calculated column will provide the average you want.

Example:

Assume the following 3 values for a student in your grade columns: 8/10, 3/5, 2/2

The Average Calculated Column uses the following formula to calculate its "average" percent correct:

[(Column 1%) + (Column 2%) + (Column 3%) + . . . (Column N%)]/ (N Columns)

= (80.0000% + 60.0000% + 100%)/3 = 240%/3 = 80%

The Total Calculated Column uses the following formula to calculate its "average" percent correct:

[(Column 1 Points) + (Column 2 Points) + (Column 3 Points) + . . . (Column N Points)]/(Number of Points Possible) X 100%

= (8 + 3 + 2)/(10 + 5 + 2) X 100% = (13/17) x 100% = 0.7647 X 100% = 76.47%

Access the Full Grade Center

If you need assistance accessing the Full Grade Center, please refer to the module Accessing the Full Grade Center.

Select the Type of Calculated Column You Want to Create

Select the Type of Calculated Column You Want to Create
  1. Click the Create Calculated Column button to display the drop-down menu of options
  2. Select the type of Calculated Column you want to create from the list of four types available.

A. Average Column

An Average Column calculates and displays the "mean percentage correct" for a selected number of Columns. Columns with text as the primary display cannot be used in this calculation.

Step 1 - Select Average Column

Step 1 - Select Average Column

Select Average Column from the list of Calculated Column types. You should now see the Create Average Column screen.

Create Average Column Screen

Step 2a - Fill out or choose the Column Information options

Fill in the following information in Column Information:

  1. Enter a descriptive name for the Column. Note that if a Column Name is not entered, only the first 15 characters of this name are displayed in the Full Grade Center.
  2. Enter the Grade Center Name--this might be a shorted version (15 characters or less) of the Column Name in preceding step.
  3. This option text Description can help other instructors and TAs identify the Grade Column.
  4. Primary Display is the grade format shown in the Grade Center and to students. Options include Score, Text, Percentage, Letter, and Complete/Incomplete.
  5. The Secondary Display option shows the grade format in the Grade Center only. The Secondary Display is denoted by parentheses and is shown just to the immediate right of the Primary Display in the same grade cell. Note: students will not be able to see the secondary score when viewing their grades--only the primary score is shown to them.

Step 2b - Select columns to include in Average and whether to calculate as a Running Total

  1. Include in Average: Choose All Grade Columns to included all graded columns in the average. If this option is chosen, then the none of the information in the gray box area will be displayed. Choose Selected Columns and Categories to include specific columns or categories of columns in the average.
  2. If you chose Selected Columns and Categories in the previous step, you can then choose the Columns to Select by clicking on the name of a specific column and then click the ">" arrow to move the column name to the Selected Columns area. To choose all columns in a specific Category, click on the name of the Category in the Categories to Select box and then click the ">" arrow to move the category name over to the Selected Columns area.
  3. When you select a category of columns to include, Weight Columns allows you determine how the columns are weighted within the category. Choosing Equally applies an equal value to all columns within this category. Choosing Proportionally, applies the appropriate value to a column based on its points compared to other columns in the category.

    Also when you select a category of columns to include in the Average, you have the options of dropping a specified number of the Highest or Lowest grades or using only the Highest or Lowest grade from all columns in this category to calculate the Average.
  4. Selecting Yes for Calculate as a Running Total calculates the Average by including only the Grade Columns that have been graded or have values entered. Selecting No for this option includes all selected columns in the calculations, using zero (0) for columns that have not been graded. This can make grades appear artificially low since zeroes will be used in all columns for tests and assignments that have not yet been taken or were missed.

Step 2c - Set the column Options settings.

  1. Select Yes to include the column in any future Grade Center calculations. For example, the default Total column, will automatically (unless otherwise specified) include the scores from all columns for which this option has been set to Yes.
  2. Select Yes to release column data to students. If this is set to No, then students will not be able to see their score for this column in the My Grades area.
  3. Select Yes to release the class mean and median to your students (in addition to their own score).
  4. Click the Submit button at the bottom of the page when finished to create the column.

B. Minimum/Maximum Column

A Minimum/Maximum Column calculates either the minimum or maximum grade for a selected number of Columns. Columns with text as the primary display cannot be displayed as a minimum or maximum grade.

Step 1 - Select Minimum/Maximum Column

Step 1 - Select Minimum/Maximum Column

Click the Create Calculated Column button and then select Minimum/Maximum Column from the drop-down menu. You should now see the Create Minimum/Maximum screen shown below.

Create Minimum/Maximum Screen

Step 2a - Fill out or select the options for Column Information

Fill in the following information in Column Information:

  1. Enter a descriptive name for the Column. Note that if a Column Name is not entered, only the first 15 characters of this name are displayed in the Full Grade Center.
  2. Enter the Grade Center Name--this might be a shorted version (15 characters or less) of the Column Name in preceding step.
  3. This option text Description can help other instructors and TAs identify the Grade Column.
  4. Primary Display is the grade format shown in the Grade Center and to students. Options include Score, Text, Percentage, Letter, and Complete/Incomplete.
  5. The Secondary Display option shows the grade format in the Grade Center only. The Secondary Display is denoted by parentheses and is shown just to the immediate right of the Primary Display in the same grade cell. Note: students will not be able to see the secondary score when viewing their grades--only the primary score is shown to them.

Step 2b - Select columns to include and whether to calculate as a Running Total

  1. Select whether you want to calculate a Minimum or Maximum for the selected columns.
  2. Choose All Grade Columns to included all graded columns in the Minimum or Maximum. If this option is chosen, then the none of the information in the gray box area will be displayed. Choose Selected Columns and Categories to include specific columns or categories of columns in the Minimum/Maximum calculation.
  3. If you chose Selected Columns and Categories in the previous step, you can then choose the Columns to Select by clicking on the name of a specific column and then click the ">" arrow to move the column name to the Selected Columns area. To choose all columns in a specific Category, click on the name of the Category in the Categories to Select box and then click the ">" arrow to move the category name over to the Selected Columns area.

    To remove a selected Column or Category, click the red circled "x" to the right of the name or category in the Selected Columns box.
  4. Selecting Yes for Calculate as a Running Total calculates the Minimum or Maximum by including only the Grade Columns that have been graded or have values entered. Selecting No for this option includes all selected columns in the calculations, using zero (0) for columns that have not been graded. This can make grades appear artificially low since zeroes will be used in all columns for tests and assignments that have not yet been taken or missed.

Step 2c - Set the column Options settings

  1. Select Yes to include the column in any future Grade Center calculations. For example, the default Total column, will automatically (unless otherwise specified) include the scores from all columns for which this option has been set to Yes.
  2. Select Yes to release column data to students. If this is set to No, then students will not be able to see their score for this column in the My Grades area.
  3. Select Yes to release the class mean and median to your students (in addition to their own score).
  4. When finished, click the Submit button at the bottom of the screen to create the column.

C. Total Column

A Total Column simply sums the total points for a number of Columns related to the total number of points allowed. Total Columns are useful for generating a final score. Columns with text as the primary display cannot be totaled. Total Columns can be set to calculate a total for all selected columns (including those for which no score has been recored or graded--using a "0"), or to calculate a Running Total which includes only those columns for which a score has been entered either manually or automatically. Columns with a blank score are skipped for that particular student and thus each student may have a unique number of possible points.

Step 1- Select Total Column

Step 1- Select Total Column

Click the Create Calculated Column button and then select Total Column from thedrop-down menu. You should now see the Create Total screen shown below.

Create Total Column Screen

Step 2a - Fill out or select the options for Column Information

Fill in the following information in Column Information:

  1. Enter a descriptive name for the Column. Note that if a Column Name is not entered, only the first 15 characters of this name are displayed in the Full Grade Center.
  2. Enter the Grade Center Name--this might be a shorted version (15 characters or less) of the Column Name in preceding step.
  3. This option text Description can help other instructors and TAs identify the Grade Column.
  4. Primary Display is the grade format shown in the Grade Center and to students. Options include Score, Text, Percentage, Letter, and Complete/Incomplete.
  5. The Secondary Display option shows the grade format in the Grade Center only. The Secondary Display is denoted by parentheses and is shown just to the immediate right of the Primary Display in the same grade cell. Note: students will not be able to see the secondary score when viewing their grades--only the primary score is shown to them.

Step 2b - Select columns to include and whether to calculate as a Running Total

  1. Include in Total: Choose All Grade Columns to included all graded columns in the average. If this option is chosen, then the none of the information in the gray box area will be displayed. Choose Selected Columns and Categories to include specific columns or categories of columns in the average.
  2. If you chose Selected Columns and Categories in the previous step, you can then choose the Columns to Select by clicking on the name of a specific column and then click the ">" arrow to move the column name to the Selected Columns area. To choose all columns in a specific Category, click on the name of the Category in the Categories to Select box and then click the ">" arrow to move the category name over to the Selected Columns area.
  3. When you select a Category of columns to include, you have the option of dropping a specified number of the Highest or Lowest grades or using only the Highest or Lowest grade from all columns in this category.
  4. Selecting Yes for Calculate as a Running Total calculates the Total by including only the Grade Columns that have been graded or have values entered. Selecting No for this option includes all selected columns in the calculations, using zero (0) for columns that have not been graded. This can make grades appear artificially low since zeroes will be used in all columns for tests and assignments that have not yet been taken or were missed.

Step 2c - Set the column Options settings

  1. Select Yes to include the column in any future Grade Center calculations. For example, the default Total column, will automatically (unless otherwise specified) include the scores from all columns for which this option has been set to Yes.
  2. Select Yes to release column data to students. If this is set to No, then students will not be able to see their score for this column in the My Grades area.
  3. Select Yes to release the class mean and median to your students (in addition to their own score).
  4. When finished, click the Submit button to create the column.

D. Weighted Column

A Weighted Column calculates and displays a grade based for a selected number of columns or category of columns based upon each column's respective worth of the total grade. Columns with text as the primary display cannot be displayed as a weighted grade. Each selected Grade Column or Category of columns must be assigned a percentage of the total score. You are also given the option of dropping the a specified number of the highest or lowest grade in a particular category.

Proportional vs Equal Weighting when including Categories

Whenever you create a Weighted Column and include categories of columns (for example, tests, quizzes, discussion, papers, etc.) you will need to choose between proportional weighting and equal weighting for each category that you choose to include in the calculation. Therefore it's very important to understand the difference between the two.

Proportional vs. Equal weighting is a setting when you weight by category. It only makes a difference if you have columns with different points possible in the same category (e.g. a Discussion category with columns worth 5 points and columns worth 10 points). If all of the columns in the category are equal, both settings work the same way.

When you have categories of differing values, Equal Weighting converts the columns to percentages and averages the percentages to get the category composite grade. It essentially gives each item equal weight when determining the composite grade. Proportional weighting calculates a category composite grade by adding the raw scores and dividing by the total points possible. It retains the proportional weight of each item, so items with a larger value have more effect on the composite grade.

For example, consider two assignments in a category, one worth 5 points and the other worth 10 points. Assume the student gets 5 points on each assignment.

Equal weighting: 5/5 and 5/10 = (100% + 50%) / 2 = 75% (or you can think of converting it to equal Points Possible: 10/10 and 5/10 = 15/20) 


Proportional weighting: 5/5 and 5/10 = 10/15 = 66.7%

The category composite grade is then weighted according to the percentage you indicated for the entire category and combined with the other columns or categories you have included in the Weighted Total.

Step 1 - Select Weighted Column

Step 1 - Select Weighted Column

Click the Create Calculated Column button and then select Weighted Column from the drop-down menu. You should now see the Create Weighted Column screen shown below.

Create Weighted Column Screen

Step 2a - Fill out or select the options for Column Information

Fill in the following information in Column Information:

  1. Enter a descriptive name for the Column. Note that if a Column Name is not entered, only the first 15 characters of this name are displayed in the Full Grade Center.
  2. Enter the Grade Center Name--this might be a shorted version (15 characters or less) of the Column Name in preceding step.
  3. This option text Description can help other instructors and TAs identify the Grade Column.
  4. Primary Display is the grade format shown in the Grade Center and to students. Options include Score, Text, Percentage, Letter, and Complete/Incomplete.
  5. The Secondary Display option shows the grade format in the Grade Center only. The Secondary Display is denoted by parentheses and is shown just to the immediate right of the Primary Display in the same grade cell. Note: students will not be able to see the secondary score when viewing their grades--only the primary score is shown to them.

Step 2b - Select columns or categories to include and whether to calculate as a Running Total

Step 2b - Select columns or categories to include and whether to calculate as a Running Total
  1. Choose the Columns and/or Categories that you want to include in your calculation.  You can choose the Columns to Select by clicking on the name of a specific column and then click the ">" arrow to move the column name to the Selected Columns area. To choose all columns in a specific Category, click on the name of the Category in the Categories to Select box and then click the ">" arrow to move the category name over to the Selected Columns area.

  2. In the Selected Columns box, you must then enter the weight percentage for each Column and/or Category that you have chosen. Make sure that all the percentages entered add up to 100%.
  3. When you select a Category of columns to include, the Weight Columns option allows you determine how the columns are weighted within the category. Choosing Equally applies an equal value to all columns within this category. Choosing Proportionally, applies the appropriate value to a column based on its points compared to other columns in the category.

    Also for a Category of selected columns, you have the option of dropping a specified number of the Highest or Lowest grades or using only the Highest or Lowest grade from all columns in this category.
  4. Selecting Yes for Calculate as a Running Total calculates the Weighted Column by including only the Grade Columns that have been graded or have values entered. Selecting No for this option includes all selected columns in the calculations, using zero (0) for columns that have not been graded. This can make grades appear artificially low since zeroes will be used in all columns for tests and assignments that have not yet been taken or were missed.

Step 2c - Set the column Options settings

  1. Select Yes to include the column in any future Grade Center calculations. For example, the default Total column, will automatically (unless otherwise specified) include the scores from all columns for which this option has been set to Yes.
  2. Select Yes to release column data to students. If this is set to No, then students will not be able to see their score for this column in the My Grades area
  3. Select Yes to release the class mean and median to your students (in addition to their own score).
  4. When finished, click the Submit button to create the weighted column.