Current Issues with the Blackboard Grade Centre

When upgrading Blackboard, we make every effort to test and document as much of the system as possible. However, it is not always possible to test every last feature, and as such we sometimes find bugs with the system after upgrades.

  • Calculated Formula Question Marked Incorrect Despite Matching the Correct Answer

Issue Description: Calculated formula question marked incorrect despite matching the correct answer. This is an issue with the Calculated Formula grader when grading exponential numbers. Effectively when a User uses a higher or lower notation than the expected answer it will fail, although it is mathematically equivalent. A basic example is the answer for an exponential answer is: 1.66E-24 if you put the following value in: 166E-26 it will be marked as incorrect, even though it is mathematically correct.

Steps to Replicate:

  1. Create a new Course.
  2. Create a Test Assessment.
  3. Create a Calculated Question.
  4. Use the following Question Text: How many moles is a [x] molecule sample? For full credit include the correct abbreviated unit with your answer.
  5. Use the following Formula: x/6.022×10^23.
  6. Set Answer Units to: mol.
  7. Set Precision to 3 Significant Figures.
  8. Set the following MIN MAX values: 652.0. (0 Decimal Places)
  9. Set Correct Answer Forum to: Exponential.
  10. Set Answer Sets to: 1.
  11. Perform a calculate and make note of the answer. (It should be 1.66E-24)
  12. Save the Assessment and go in as an Instructor and attempt the Assessment. You should have set all feedback options to see the values being marked.
  13. In the answer box type the following: 1.66E-24mol.
  14. Submit the Assessment and see the feedback.
    • Note: You should have gotten a correct score. If not go in again and use that correct score to confirm.
  15. Now attempt it again and change the value by removing the period in the value and increasing the exponential value by 2. IE: 1.66E-24 will turn into: 166E-26
  16. This is still correct, and exponential works so that effectively you are just moving the decimal. So increasing it by 2 is still technically the right answer.
  17. Attempt to Submit with this new value.

Observed Behaviour: 
Note that answer will be marked wrong, but they will show as the same. This appears to be an issue with how to grade these.

Expected Behaviour: 
As the value is still the same, it should be marked correctly.