Flowcharts and Pseudocode

OCR

GCSE

Flowcharts and pseudocode serve as intermediate representations of algorithms, bridging the gap between natural language problem statements and high-level programming syntax. Flowcharts utilize standardized ISO symbols to visually map control flow, emphasizing the structural relationship between sequence, selection, and iteration. Pseudocode abstracts logic from specific language syntax, allowing for the precise definition of variables, constructs, and algorithmic efficiency. Mastery of these tools is essential for decomposing problems, performing dry runs via trace tables, and verifying logic prior to implementation.

Objectives

Exam Tips

Pitfalls

Key Terms

Mark Points

What You Need to Demonstrate

Key skills and knowledge for this topic

Award 1 mark for the correct use of standard flowchart symbols: parallelograms for I/O, diamonds for decisions, rectangles for processes
Credit correct logic flow in pseudocode, specifically the correct indentation and syntax for nested 'if' or 'while' constructs
Award marks for correct variable handling, including meaningful identifiers and initialization before use
Credit the accurate use of arithmetic and boolean operators, particularly distinguishing between '=' (assignment) and '==' (comparison)
Award 1 mark for a structure diagram that shows strict hierarchical decomposition rather than chronological flow

Marking Points

Key points examiners look for in your answers

Award 1 mark for the correct use of standard flowchart symbols: parallelograms for I/O, diamonds for decisions, rectangles for processes
Credit correct logic flow in pseudocode, specifically the correct indentation and syntax for nested 'if' or 'while' constructs
Award marks for correct variable handling, including meaningful identifiers and initialization before use
Credit the accurate use of arithmetic and boolean operators, particularly distinguishing between '=' (assignment) and '==' (comparison)
Award 1 mark for a structure diagram that shows strict hierarchical decomposition rather than chronological flow

Examiner Tips

Expert advice for maximising your marks

💡When asked to write an algorithm, you may use OCR Reference Language, Python, or C#, but stick to one style consistently; do not mix natural language with code
💡For structure diagrams, ensure the hierarchy breaks the problem down into sub-problems (modules), not a chronological sequence of events like a flowchart
💡In trace tables, create a new row for every variable change; never overwrite values or put multiple changes in one cell unless they happen simultaneously
💡Memorize the specific OCR Reference Language syntax for file handling (open, read, write, close) as this is frequently tested in 'Complete the code' questions

Common Mistakes

Pitfalls to avoid in your exam answers

Using a rectangle (process box) for Input/Output operations in flowcharts instead of the required parallelogram
Confusing the assignment operator '=' with the comparison operator '==' when writing pseudocode or Python
In structure diagrams, attempting to show data flow (arrows) or logic decisions instead of a strict top-down hierarchy of sub-problems
Confusing the integer division operator 'DIV' (quotient) with the modulus operator 'MOD' (remainder)

Study Guide Available

Comprehensive revision notes & examples

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Key Terminology

Essential terms to know

Standard Flowchart Symbols (Terminator, Process, Decision, I/O, Subroutine)

Structured Programming Constructs (Sequence, Selection, Iteration)

Algorithmic Trace Tables and Dry Running

Variable Assignment and State Changes

Likely Command Words

How questions on this topic are typically asked

Create

Draw

Complete

Correct

Identify

Describe

Practical Links

Related required practicals

•{"code":"Programming Project Skills","title":"Design Phase","relevance":"Application of decomposition and abstraction to real-world scenarios"}

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