OCR vs AQA vs IB vs Cambridge Pseudocode Comparison Guide
The definitive Rosetta Stone guide for Computer Science students and teachers. Compare syntax rules across Cambridge (CAIE), OCR Exam Reference Language (ERL), AQA, and IB Computer Science.
1. The Multi-Board Pseudocode Rosetta Stone (Side-by-Side Comparison)
| Feature / Operation | Cambridge (0478/9618) | OCR ERL (J277/H446) | AQA (8525/7517) | IB Computer Science |
|---|---|---|---|---|
| Variable Assignment | Count ← Count + 1 |
count = count + 1 |
count = count + 1 (or ←) |
COUNT = COUNT + 1 |
| Console Output | OUTPUT "Hello" |
print("Hello") |
OUTPUT "Hello" |
output "Hello" |
| User Input | INPUT Name |
name = input() |
USERINPUT Name |
input NAME |
| Array Declaration | ARRAY[1:10] OF INT |
array scores[10] |
scores = [0, 0, 0] |
SCORES = new Array() |
| Array Indexing | 1-indexed default | 0-indexed strictly | 0-indexed strictly | 0-indexed (or spec) |
| Counted FOR Loop | FOR i ← 1 TO 10 ... NEXT i |
for i = 1 to 10 ... next i |
FOR i ← 1 TO 10 ... ENDFOR |
loop I from 1 to 10 ... end loop |
| Pre-Condition Loop | WHILE c DO ... ENDWHILE |
while c ... endwhile |
WHILE c ... ENDWHILE |
loop while c ... end loop |
| Post-Condition Loop | REPEAT ... UNTIL cond |
do ... until cond |
REPEAT ... UNTIL cond |
loop until cond ... end loop |
| Inequality Check | X <> Y |
x != y (or !=) |
x ≠ y (or !=) |
X <> Y (or !=) |
| Integer Division | x DIV y |
x DIV y |
x DIV y |
x div y |
| Modulo Remainder | x MOD y |
x MOD y |
x MOD y |
x mod y |
2. OCR Exam Reference Language (ERL): Key Differences & Python Influence
For UK students sitting OCR GCSE (J277) and A-Level (H446) Computer Science, the exam board specifies an official Exam Reference Language (ERL):
- Heavy Python Influence: Unlike Cambridge, OCR ERL borrows directly from Python. It uses
print("text")andinput("prompt")with parentheses. - 0-Based Array Indexing: An array declared as
array scores[10]has valid indices from0through9. Accessingscores[10]is an error. - Assignment Equals: OCR ERL uses single equals
=for variable assignment (e.g.total = 0) and double equals==for boolean comparisons.
3. AQA GCSE (8525) & A-Level (7517) Pseudocode Conventions
AQA takes a pragmatic approach, accepting both pseudo-English and programming language conventions on Paper 1 and Paper 2:
- Block Closures: AQA explicitly closes constructs with
ENDFOR,ENDWHILE, andENDIF. - Subroutine Definitions: AQA distinguishes between subroutines that return values (
FUNCTION) and those that do not (SUBROUTINEorPROCEDURE), usingENDSUBROUTINEto close. - Liberal Operator Mark Schemes: AQA mark schemes explicitly credit candidates who write either
←or=for assignment, and≠or!=for inequality.
4. IB Computer Science Pseudocode Rules (Paper 1 & Paper 2)
International Baccalaureate (IB) candidates frequently find Cambridge pseudocode compilers confusing because IB uses distinct loop vocabulary:
- Unified Loop Syntax: IB uses
loop ... end loopfor all loop types:- Count-controlled:
loop I from 1 to 10 ... end loop - Pre-condition:
loop while CONDITION ... end loop - Post-condition:
loop until CONDITION ... end loop
- Count-controlled:
- Methods & Collections: IB pseudocode incorporates built-in dynamic collections (
STACK,QUEUE) with methods like.push(),.pop(),.enqueue(), and.isEmpty()directly into Paper 1.
5. Testing Multi-Board Algorithms in PseudoStudio IDE
While PseudoStudio strictly compiles Cambridge pseudocode by default, students studying OCR, AQA, or IB benefit tremendously from practicing in our environment:
- Algorithmic Logic is Universal: Trace tables, bubble sorting, binary search, linear traversals, and validation loops function identically across all boards.
- Interactive Trace Table Dry-Running: Paste any algorithm into our Trace Table Generator to visually verify iteration states regardless of your syllabus.
- Flowchart Generation: The standard ISO shapes used in our SVG Flowchart Maker are 100% standardized across Cambridge, OCR, AQA, and Edexcel.
6. Frequently Asked Questions: Multi-Board Pseudocode Standards
Why do different exam boards use different pseudocode?
Because pseudocode is not a compiled programming language, each examination board developed their own reference language to help examiners write consistent questions and grade student responses fairly.
Can I use Cambridge pseudocode in an OCR exam?
OCR examiners are instructed to award marks for valid algorithmic logic, even if candidates use Cambridge conventions (like left arrows or 1-based arrays), provided the candidate's logic is clear and unambiguous.
Can I convert between different pseudocode styles?
Yes. You can use our AI Pseudocode Generator or Pseudocode to Python Converter to translate code from any board into strict Cambridge format or Python 3.
Practice Algorithmic Problem Solving Online
Trace algorithms, generate flowcharts, and solve exam-style practice questions in your browser.