Blackboard 9 - Calculated Columns

Transcription

1 University of Southern California Marshall Information Services Blackboard 9 - Calculated Columns The Blackboard Grade Center allows you to create columns that will display a total based on the numeric content of other columns. This guide covers how to make the different types of calculated columns and the options available in each type. Note that it is assumed that you already know how to create non-calculated columns and how to create and assign categories. To learn how to make non-calculated columns and work with categories, please see these guides: Creating Non-Calculated Columns Using Categories Contents Requirements for the Non-Calculated Columns (i.e. Data Columns)... 2 Hiding the Built-in Totals Column... 2 Overview of the Different types of Calculated Columns... 4 Average Column... 4 Minimum/Maximum Column (Bug Alert!)... 5 Total Column (Non-Weighted)... 5 Weighted Column (Weighted Total Column)... 6 Creating an Average Calculated Column... 7 Creating a Minimum/Maximum Calculated Column (Bug Alert!) Creating a Total Calculated Column Creating a Weighted Total Calculated Column Appendix Understanding Calculate a Running Total If you Select Yes If you Select No Marshall School of Business Calculated Columns.docx 12/3/2012 Page 1 of 19

2 Requirements for the Non-Calculated Columns (i.e. Data Columns) To display results, calculated columns use data in other columns of your grade book (data columns). When creating your data columns, they need to possess the characteristics below to be used in a calculated column. Grading Periods - If you are using grading periods, the data columns must be in the same grading period as the calculated column. If you aren t using grading periods then leave them all set to None. Include In Calculations - The data columns must have Include this column in Grade Center Calculations set to Yes to be included in a calculated column. Not be a Text Column The data columns Primary Display Type must not be set to Text. Score, Percent, Complete/Incomplete, and Letter (or a custom grading schema) are all fine. Categories If you are using categories to specify which columns to calculate, your data columns must be placed in the category specified in your calculated column. If you don t use categories then leave them all to No Category. Hiding the Built-in Totals Column While this guide covers how to create new calculated columns in your grade book, it should be pointed out that there is a built-in Total column that will total all non-calculated number columns in your grade book as a non-weighted total. If desired, you can edit it ( Edit Column Information ) to total only the columns you wish or hide it from students as shown below. Follow the steps below if you wish to hide the built-in Totals column from students. 1. From within the grade center, click the Total column s drop down arrow. 2. Click Edit Column Information. 3. At Show this Column to Students, select No. 4. Click Submit. Do NOT check Hide Column. This hides it from your view but the students can still see it! A small circle with a slash through it now appears to the left of the column indicating that it is hidden from students. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 2 of 19

3 Description Display Choices Can be Weighted by Blackboard? Can Weigh Columns Equally? (i.e. straight average) Can Drop Lowest / Highest Score? Can Use Categories? Can Use Grading Periods? Can Drop Lowest / Highest Score? Can Perform Calculation on another Calculated Column? Average Calculated Column Returns the average of a series of other columns. Score, percentage, complete/incomplete, or letter grade if you have configured a grade curve for the course. The default is to return a weighted average. Yes, if you use categories there is a choice to weight them equally. Yes, if you use categories. Summary of Calculated Columns Minimum/Maximum Calculated Column Returns the minimum or maximum sore of a series of other columns. Score, percentage, complete/incomplete, or letter grade if you have configured a grade curve for the course. No No No Total Calculated Column Returns the total of a series of other columns. Score, percentage, complete/incomplete, or letter grade if you have configured a grade curve for the course. No. This is a straight total only. No Yes, if you use categories. Weighted Total Calculated Column Returns a weighted total of a series of other columns. Score, percentage, complete/incomplete, or letter grade if you have configured a grade curve for the course. Yes. This is the purpose of using this type of column. Yes, if you use categories there is a choice to weight them equally. Yes, if you use categories. Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes No No Yes Yes Marshall School of Business Calculated Columns.docx 12/3/2012 Page 3 of 19

4 Overview of the Different types of Calculated Columns The four types of calculated columns (Average, Minimum/Maximum, Total, and Weighted) are explained below. Average Column This calculates and displays the average of the columns involved as a score, percent, or letter grade if you are using grading schemeas. It is useful when students are graded on their average over a series of quizzes or projects. It normally calculates a weighted average but can calculate a straight average if you use Categories. You can also drop the lowest or highest score if you use Categories. Weighted Average The example below shows a weighted average. Even though each quiz is worth a different number of points, they all have the same impact (25%) on the total. Out of four quizzes, both students aced three of them, and one student got 5/10 on Quiz A and another student got 10/20 on Quiz D. Their average score is the same because they both have three quizzes with 100 % correct and one quiz with 50% correct. 10pts 12pts 16pts 20pts Explaining Weighed Average to Students When Displaying as a Score If you do display the total as a Score rather than a Percent, you will probably have students telling you that their average is not correct. You will need to explain to them that this is a weighted average not a straight average. In the example below, both student s quiz scores add up to divided by 4 comes out to a straight average of 12 and yet you can see they received completely different weighted averages. Student 1 Student 2 Mathematically, this is what is happening: Wt Pts Possible Per Quiz * [(1/Q1 *Q1 earned ) + (1/Q2 *Q2 earned )+ (1/Q3 *Q3 earned ) + (1/Q4 *Q4 earned )] Student1: (( )/4/4) * [ (1/10*10) + (1/12*5) + (1/16*13) + (1/20*20) ] = Student 2: (( )/4/4) * [ (1/10*10) + (1/12*12) + (1/16*16) + (1/20*10) ] = Straight Average by Using Categories If you want a straight average, then you have to create a category, place each quiz in that category, and then base the average column on the category using the Proportionally option. The example below shows the same quiz results as above but a straight average is used. As you can see, getting 10/20 is better than getting 5/10. Rather than looking at the percent correct for each column, Blackboard simply adds up each student s four quiz scores and then divides by the number of quizzes (i.e. Total / 4) 10pts 12pts 16pts 20pts Marshall School of Business Calculated Columns.docx 12/3/2012 Page 4 of 19

5 Minimum/Maximum Column (Bug Alert!) This displays highest score (or percent) of the quiz that has the highest percent of correct answers. For example, the second student s got 12/12 on Quiz B and 19/20 on Quiz D. Because their percent correct for Quiz B is higher than their percent correct on Quiz D, the calculated column displays a 12. (If we were displaying our quiz scores as percentages rather than scores, what s going on would be more obvious.) Note that this can also display the lowest scores. Will display incorrect results with decimal numbers! 10pts 12pts 16pts 20pts Note that while you can use categories, you cannot drop the lowest or highest score with the Minimum/Maximum type. Total Column (Non-Weighted) This column displays the sum of all columns involved as a non-weighted score or a percent of the total. The columns involved can be selected individually, by grading period, by category, or you can select them by selecting another calculated column that they are a part of. Note that there is no option to weight a Total Column even when using categories. Example A Total Column is useful for displaying a total when the individual item s numeric scores are proportional to their desired impact on the total. For example, an instructor is giving five quizzes, a midterm, and a final. The quizzes should be worth 50% of the final grade, the midterm 20%, and the final 30%. He s decided to achieve his grading scheme by making the points for each item proportional to their percent impact on the final grade as shown below. Type Percent of Final Grade Points Possible Quizzes (5 Quizzes) 50% 10 Points per quiz = 50 points Midterm 20% 20 Final 30% 30 In Blackboard, this is very straightforward. The instructor simply types the scores for each item in and then uses the Total Column to sum them up. No adjustment for weight is necessary in Blackboard because he the instructor has already done that beforehand by making his points proportional to its weight on the final grade. 50 points 20 points 30 points The disadvantage of this method is that the instructor may have to do the math to make the points equal their effect on the final grade before typing data into Blackboard. For example, what if each quiz had a different number of questions? The instructor would have to do some calculations to adjust their totals to equal 10 points each prior to typing them in Blackboard. If this is the case, a better approach might be to use the Weighted Total shown below and let Blackboard do the math and adjust the proportionality for you. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 5 of 19

6 Weighted Column (Weighted Total Column) Weighted Total displays the sum of all columns involved just as the Total Column shown above does; however, Weighted Total also allows you to give the data columns used in the calculation different weights. This is very useful when the points in your data columns do not reflect the impact you wish the column to have on the total score. The columns involved can be selected individually, by grading period, by category, or you can select them by selecting another calculated column that they are a part of. You can display the total as a numeric score, a percentage of the total, or a letter if you are using grading schemas. For example, in the table below, the points for each column reflects the number of questions on each test or quiz and is only loosely related to how much the instructor wants each item to affect course total. As you can see, the midterm has 80 points and the final has 90 points yet each one needs to impact the course grade equally at 25% each. Further, each quiz also has a different number of questions and hence points yet the instructor wants all quizzes to be weighted equally and make up 30% of the final grade. A Weighted Column allows you to accomplish all this by allowing you to specify the percent each column should affect the final grade. 30% of Course Grade 25% of Course Grade 25% of Course Grade 20% of Course Grade 10pts 12pts 16pts 20pts 80pts 90pts 20pts You can also display the total as a percent. Below is a snapshot of the screen in Blackboard that allows you to assign percentages to columns. Note the image shows each column being assigned percentages individually but you can assign percentages by categories as well. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 6 of 19

7 Creating an Average Calculated Column This section covers the steps to create a weighted (or straight) average column. For example, the Wt Average Total column below returns the weighted average of quizzes A-D. Note you can also return the average as a percent. 10pts 12pts 16pts 20pts 1. Access the course you wish to affect. 2. In Control Panel, click Grade Center then Full Grade Center. 3. Click Create Calculated Column. 4. Select Average Column. 5. Type a Column Name. 6. Specify whether you want the average to display as a Percent, Score, or if you using grading schemas, select the grading schema to use. Grading Period (Optional) Unless you are using grading periods, you can leave this at none. Secondary Display (Optional) This allows the instructor to see two display types in the same column. Students can only see the primary display. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 7 of 19

8 Step 7: Selecting the Columns to Calculate You must now specify the method you wish to use to specify which columns will be included in the calculation to get the average: To calculate the average of all columns in your grade book, select All Grade Columns. (This method always returns a weighted average.) To calculate the average of specific columns in your grade book, select Selected Columns and Categories. (This method returns a weighted average or can return a straight average if you use Categories.) Example of using a Weighted Average The image below shows an instructor using the Selected Columns and Categories option to base the average on Quizzes A, B, C, & D only. Using this method, Blackboard will return a weighted average. Using a Weighted Average If you select All Grade Columns or select specific columns to be included, Blackboard will do a weighted average as shown below. Use this button to move the columns you highlighted on the left into the Selected Columns window. 10pts 12pts 16pts 20pts Max Average Possible is 14.5 Marshall School of Business Calculated Columns.docx 12/3/2012 Page 8 of 19

9 Example of a Weighted Average, Straight Average or Dropping the Lowest Score: Selected Columns and Categories You can also specify which columns to include in the calculations by selecting the Category they are assigned to (you must have placed them in a category). Using categories has the advantage of also allowing you to use a straight average (i.e. non-weighted) and if desired, dropping the lowest score. (You can still use categories with a weighted average and not drop the lowest score.) Using a Straight Average If you want a straight (non-weighed) average, you must place the columns you wish to calculate in a Category, and select the Category as shown here. (See the guide on Categories for instructions for making Categories.) Use this button to select the highlighted category. Use this button to select If you have selected quizzes by Category, you can also categories. elect to drop the lowest or highest X number of scores. If you have selected quizzes by Category, you can specify a weighted total ( Equally ) or a straight total ( Proportionally ). The image below shows the same quizzes used on the previous page but with a straight average (Proportionally) rather than a weighted average. Note that the scores now differ between the two students and from the example on the previous image. 7. Select the columns to be included in the average using one of the methods shown on the last two pages. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 9 of 19

10 The next step is to specify Yes or No at Calculate as Running Total. If you select Yes, then Blackboard will completely ignore any scores with blanks when calculating the average. If you select No, then Blackboard will treat a blank as if the student received a zero in the column. (See the appendix of this handout for a more detailed explanation.) 8. I suggest selecting No for Calculate as Running Total. (See the appendix of this guide for an explanation.) 9. Set options as desired and then click Submit. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 10 of 19

11 Creating a Minimum/Maximum Calculated Column (Bug Alert!) This displays the highest score (or percent) of the quiz that has the highest percent of correct answers. For example, the second student s got 12/12 on Quiz B and 19/20 on Quiz D. Because their percent correct for Quiz B is higher than their percent correct on Quiz D, the calculated column displays a 12. (If we were displaying our quiz scores as percentages rather than scores, what s going on would be more obvious.) Note that this can also display the lowest scores. Will display incorrect results with decimal numbers! 10pts 12pts 16pts 20pts DO NOT USE THIS OPTION IF ANY OF YOUR SCORES CONTAIN DECIMALS! Use whole numbers only. The Minimum/Maximum calculated column contains a bug and may not calculate correctly if you use fractions. 1. Access the course you wish to affect. 2. In Control Panel, click Grade Center then Full Grade Center. 3. Click Create Calculated Column. 4. Select Maximum/Minimum Column. 5. Type a name for the new column. 6. Set the Primary Display to either Score or Percent. (You can also choose Letter but you must have created a class grading curve.) If you are using grading periods, specify a grading period. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 11 of 19

12 7. Specify whether you wish to return the student s best performance or worst performance. 8. You must now specify how you want to select the columns. Both All Grade options will only look at data columns and ignore calculated columns. This example shows the user selecting by specific columns. To pick and choose that columns you wish to compare select Selected Columns and Categories as shown here. If you used categories, you can also select columns by selecting their category. Note that with the Maximum/Minimum calculated columns, you cannot drop the lowest grade or set weights as you can with some of the other column types. 9. Using one of the methods shown above, select the columns you wish to be included in your calculated column. 10. At Calculate as Running Total, specify Yes or No. (See the appendix of this guide for an explanation.) Yes A blank column is not considered when evaluating the columns but a column with a zero in it is. No Blank columns are seen as getting a zero and the column is considered. 11. Set any other options as desired and then click Submit. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 12 of 19

13 Creating a Total Calculated Column This column displays the sum of columns specified as a non-weighted score or a percent. The columns involved can be selected individually, by grading period, by category, or you can select them by selecting another calculated column that they are a part of. You should use a Total Calculated Column when the scores you are typing into Blackboard are proportional to the weight you are giving each assignment towards the calculated column. In the example below, quizzes are 50% of the final grade so each one is worth 10pts, the midterm is worth 20% so it s worth 20pts, and the final is worth 30% so it s worth 30pts for a total of 100% and 100 points. If your raw scores are not proportional, then use a Weighted Total Calculated Column. 50 points 20 points 30 points 1. Access the course you wish to affect. 2. In Control Panel, click Grade Center then Full Grade Center. 3. Click Create Calculated Column. 4. Select Total Column. 5. Type a name for the new column. 6. Set the Primary Display to either Score or Percent. (You can also choose Letter but you must have created a class grading curve.) Marshall School of Business Calculated Columns.docx 12/3/2012 Page 13 of 19

14 Step 7: Selecting the Columns to Calculate You must now select the columns you wish to total. There are four different methods of doing this: All Grade Columns This totals all non-calculated columns in your grade book. You cannot drop the lowest score using this method. All Grade Columns in Grading Period This totals all non-calculated columns in the grading period you specify. You cannot drop the lowest score using this method. Selected Columns and Categories (by Category) If you have paced your data columns in Categories, this will sum all columns in the category you specify. You can also specify a grading period or drop the lowest score when using Categories. Selected Columns and Categories (by Specific Column) This allows you to pick and choose the columns you want to total by selecting them individually. You can also total other calculated columns using this method to get a grand total. You cannot drop the lowest score using this method. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 14 of 19

15 7. Use one of the methods shown on the previous page to specify the columns you wish to sum. The next step is to specify Yes or No at Calculate as Running Total. 8. I suggest selecting No for Calculate as Running Total. (See the appendix of this guide for an explanation.) 9. Set options as desired and then click Submit. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 15 of 19

16 Creating a Weighted Total Calculated Column Weighted Total displays the sum of all columns involved just as the Total Column shown above does; however, Weighted Total also allows you to give the data columns used in the calculation different weights. This is very useful when the points in your data columns do not reflect the impact you wish the column to have on the total score as in the example below. 30% of Course Grade 25% of Course Grade 25% of Course Grade 20% of Course Grade 10pts 12pts 16pts 20pts 80pts 90pts 20pts You can also display the total as a percent. 1. Access the course you wish to affect. 2. In Control Panel, click Grade Center then Full Grade Center. 3. Click Create Calculated Column. 4. Select Weighted Column. 5. Type a name for the new column. 6. Set the Primary Display to either Score or Percent. (You can also choose Letter but you must have created a class grading curve.) Marshall School of Business Calculated Columns.docx 12/3/2012 Page 16 of 19

17 Step 7: Specifying the Columns to Weigh and Total You must now specify the columns you wish to total either by column or by category. Selecting Column-by-Column Using this method you can select data columns or other calculated columns to use subtotals to get a grand total. Use this button to select the highlighted column. Once you have selected your columns, specify their weights. Their total weight is tallied on the left and should be 100%. Selecting by Category (and/or Column) If you categorized your data columns, you can select and assign percentages by category. In this example, we are using a combination of both methods. Participation, Midterm, and Final were individually selected columns and Quizzes is a category that contains Quizzes A-D. Note that if you select by Category, you can specify a grading period and/or drop the lowest score for items in that category. As above, your percentages must equal 100% Marshall School of Business Calculated Columns.docx 12/3/2012 Page 17 of 19

18 7. Use one of the methods shown on the previous page to specify the columns you wish to sum. The next step is to specify Yes or No at Calculate as Running Total. 8. I suggest selecting No for Calculate as Running Total. (See the appendix of this guide for an explanation.) 9. Set options as desired and then click Submit. Marshall School of Business Calculated Columns.docx 12/3/2012 Page 18 of 19

19 Appendix Understanding Calculate a Running Total When creating a calculated column, there is an option that asks you whether or not you want to Calculate as a Running Total. What this is asking you is how to you want the column to treat blanks when calculating the total. If you are using one of the average columns or weighted totals, then this can have a profound effect on your student s grades. If you Select Yes When Yes is selected, columns with blanks are not included in the calculations. If you are looking for an average or weighting your totals, this can give you the wrong answer because it does not treat it as a zero --- it doesn t see the column at all! As shown in the example below, students 2 & 3 got perfect scores on all of their quizzes except Quiz B. Because Student 2 has a blank for Quiz B, Blackboard found the average using the three filled in columns but for Student 3 who had a zero for Quiz B, Blackboard used all four columns to get the average. As you can see, the student with a blank got a higher average than the student with a zero even though their other quiz scores were identical. 10pts 12pts 16pts 20pts Student 1 Student 2 Student 3 As a general rule, if you are using YES, be sure to type in a zero for flunked or missed quizzes. The only reason you might want to use Yes and leave one column blank is if you are allowing each student to drop one of the quizzes. In this case, you would leave just one of the columns blank intentionally. If a student has any additional quiz that also flunked or didn t take, make sure you type a zero for those as they should be counted. Note however that I recommend using Categories if you intend to drop your students lowest quiz scores rather than setting running total to yes and leaving a column blank. If you Select No When No is selected, blanks are treated the same as if there was a zero in the column and column will be used in the calculation to get the average. As shown in the example below, a student with a blank gets the same sore as a student with a zero in the column. 10pts 12pts 16pts 20pts Student 1 Student 2 Student 3 Marshall School of Business Calculated Columns.docx 12/3/2012 Page 19 of 19