How to Set Up a Curved Grading Scale in Blackboard & Schoology

Learning management systems like Blackboard Learn and Schoology give educators powerful gradebook features for tracking assignments, quizzes, and final averages. However, when an exam proves much more difficult than expected, setting up a curved grade distribution directly inside these platforms can present challenges.

Neither Blackboard nor Schoology offers a built-in button for non-linear curve formulas like the square root curve or standard deviation bell curves. While both platforms allow custom grading schemas and calculated columns, applying advanced curve algorithms requires either export-import workflows or custom calculation columns.

This guide details how to set up curved grades in both Blackboard and Schoology, explaining native gradebook options, step-by-step export workflows, and best practices for managing grade adjustments smoothly.

Part 1: How to Curve Grades in Blackboard Learn

Blackboard Learn (including both Blackboard Original Course View and Blackboard Ultra) features a robust Grade Center. Depending on your course setup, you can adjust grades natively using Calculated Columns or externally using gradebook exports.

Option A: Blackboard Native Calculated Columns & Schema Adjustments

If you only need a flat point adjustment (adding fixed points to an assessment) or a simple linear scaling adjustment, you can use Blackboard’s native tools:

1. Calculated Columns (Flat Shift): In Blackboard Grade Center, create a new Calculated Column (Select Create Calculated Column > Total Column or Formula Column). Add the raw assignment score plus a constant value (for example, [Midterm_Score] + 5).
2. Grading Schema Adjustments: Navigate to Control Panel > Grade Center > Grading Schemas. You can edit letter grade boundaries (such as lowering the cutoff for an A from 90% to 85%) so that raw percentage scores correspond to higher letter grades across the entire course.

Limitations of Native Blackboard Tools

• Blackboard’s native formula editor supports basic arithmetic (+, -, *, /), but it does not support square root functions (√) or automated z-score normal distribution math.
• Modifying global Grading Schemas affects all assignments mapped to that schema, which may alter grades for assignments you did not intend to curve.

Option B: The Copy-Paste / CSV Export Method for Blackboard (Recommended)

To apply non-linear curves like a Texas root curve (10 × √Raw) or a standard deviation distribution without altering global course schemas, follow this workflow:

1. Export Blackboard Grade Center:
   • Go to Grade Center > Full Grade Center.
   • Click Work Offline in the top-right menu, then select Download.
   • Choose Selected Column (pick the test you want to curve) or Full Grade Center.
   • Select Comma Delimited (CSV) and click Submit, then Download.
2. Copy Raw Scores: Open the CSV file in Excel or Google Sheets. Copy the column containing your students’ raw assignment scores.
3. Calculate Curved Scores:
   • Open the online Grade Curve Calculator.
   • Paste the copied raw scores into the input box.
   • Select your desired curving algorithm:
     • Square Root Curve: Formula is 10 × √Raw Score. Boosts lower scores significantly while preserving top scores without exceeding 100%.
     • Flat Point Shift: Adds a fixed point value to all scores.
     • Linear Scale (Max Score): Scales scores based on the highest score in the class using (Raw ÷ Top Score) × 100.
     • Standard Deviation Bell Curve: Calculates grades using class mean ($\mu$μ) and standard deviation ($\sigma$σ). Learn more in our overview of bell curve grading explained.
   • Click Calculate.
4. Update Spreadsheet: Click Export CSV (or Copy Table to Clipboard) on the calculator. In your spreadsheet, create a new column named Exam 1 (Curved) and paste the new scores. Save as CSV.
5. Upload Back to Blackboard:
   • Return to Blackboard Grade Center.
   • Click Work Offline > Upload.
   • Select your updated CSV file and click Submit. Blackboard will add the new curved column to your Grade Center.

Part 2: How to Curve Grades in Schoology LMS

Schoology provides a streamlined Gradebook interface popular in K-12 and higher education. Like Blackboard, Schoology allows letter scale overrides but lacks built-in advanced curving algorithms.

Option A: Schoology Custom Grading Scales

Schoology allows instructors to create custom Grading Scales that adjust how percentage ranges map to letter grades:

1. Open your Schoology course and click Grade Setup in the left menu.
2. Under Scales / Rubrics on the right side, click Add > Scale.
3. Create a custom scale with adjusted letter boundaries (for example, setting A = 86-100%, B = 74-85%, C = 62-73%).
4. Assign this custom scale to the specific assignment under assignment settings.

Limitations of Schoology Grading Scales

• Adjusting scale boundaries changes the letter grade assigned to a score, but it does not change the numeric point value stored in the Gradebook.
• Custom scales apply uniformly across ranges and do not provide individual score-dependent adjustments like square root curves.

Option B: The Export-Import Workflow for Schoology

To curve raw point values accurately in Schoology while keeping original submissions intact:

1. Export Schoology Gradebook:
   • Open your course in Schoology and click Gradebook.
   • Click the three dots menu (Options icon) in the top-right corner of the Gradebook and select Export.
   • Choose Gradebook as CSV and click Export.
2. Copy Raw Scores: Open the exported CSV spreadsheet. Copy the raw score column for the assignment you wish to adjust.
3. Calculate Curved Scores:
   • Open the Grade Curve Calculator.
   • Paste the raw scores into the input box.
   • Choose your curving method (Square Root Curve, Flat Shift, Linear Scale, or Standard Deviation) and click Calculate.
4. Paste into Spreadsheet: Click Copy Table to Clipboard or Export CSV from the calculator output. In your spreadsheet, add a new column titled Quiz 1 – Curved and paste the updated scores. Save the file.
5. Import to Schoology:
   • In Schoology Gradebook, click the three dots menu > Import.
   • Upload your CSV file and map the new column to a new or existing assignment.

Tip: If you prefer manipulating spreadsheet formulas directly in Excel or Google Sheets, explore our guides on how to curve grades in Excel and how to curve grades in Google Sheets.

Curving Method Comparison for LMS Gradebooks

Understanding how different curving options behave helps you select the right method for your Blackboard or Schoology course:

Curving Method	Formula	Best Use Case in LMS	Score Impact
Square Root Curve	10 × √Raw Score	Difficult STEM exams where failing grades need help without inflating top scores.	High boost for low scores (+21 pts on 49), low boost for high scores (+2.5 pts on 95).
Flat Point Shift	Raw Score + Fixed Points	Minor test corrections or when 1-2 questions had errors.	Equal point gain for all students. May require capping scores at 100%.
Linear Max Score Scale	(Raw ÷ Top Score) × 100	Tests where the highest student scored an 85% instead of 100%.	Proportional scaling so the top score becomes 100%.
Standard Deviation Bell Curve	Based on Mean ($\mu$μ) and Std Dev ($\sigma$σ)	Large courses (100+ students) requiring standardized percentile distribution.	Assigns grades based on relative distance from class average.

Best Practices for LMS Grade Adjustments

• Keep Original Columns Intact: Always preserve raw assignment columns in Blackboard or Schoology. Create a separate column for curved grades so students can view both their raw score and their adjusted grade.
• Hide Grade Columns While Updating: In Blackboard, select Hide from Students (on/off) in the column menu while importing data. In Schoology, uncheck Publish to Students under assignment settings. Hide columns until all imports are verified to prevent confusion.
• Announce Curving Rules Clearly: Post a course announcement explaining which curving formula was used and why. Transparency reduces grade inquiries.
• Review Institutional Policies: Verify whether your department permits grade adjustments. For a deeper discussion on ethics and equity, see our analysis on is grading on a curve fair and review when teachers should curve grades.

Frequently Asked Questions