Mastering OCR GCSE (9-1) Computer Science (J277) requires absolute precision in register roles, comparative evaluation of hardware characteristics, strict logic in range-validation code, and proper parameter handling in Paper 2 algorithms. This package details the exact evidence-based strategies, blueprint layout, and frequent examiner pitfalls to help students secure top-tier marks.
อ่าน 3 นาทีอัปเดตเมื่อ: 21 มิ.ย. 2569
ภาพรวมข้อสอบ
จำนวนฉบับ
2
คะแนนเต็ม
160
เวลาสอบ
3ชม.
ประเภทคำถาม
5
ฉบับ
เวลา
คะแนน
จำนวนข้อ
น้ำหนักคะแนน
ประเภทคำถาม
Paper 1: Computer Systems
1ชม. 30นาที
80
19
50%
Short Answer & Conversions, Structured Explanations & Diagrams, Quality of Extended Response Essay
Paper 2: Computational Thinking, Algorithms and Programming
1ชม. 30นาที
80
20
50%
Short Answer & Program Logic MCQs, Structured Code & Circuit Drawing, Algorithm Writing & Scenario Solutions
เกณฑ์เกรด
987654321
ข้อกำหนดเครื่องคิดเลข
A scientific or graphical calculator that meets JCQ regulations may be used (some GCSE Mathematics and Science papers are non-calculator). Graphical calculators must be set to exam mode; you must clear any stored programs, notes or data before the exam, and the calculator must not be able to retrieve stored text or formulae.
AO1: Demonstrate knowledge and understanding of the key concepts and principles of Computer Science. (35%)
AO2: Apply knowledge and understanding of key concepts and principles of Computer Science to solve problems, including in design and development. (40%)
AO3: Analyse, evaluate and make reasoned judgements, and design, program, evaluate and refine solutions. (25%)
วัตถุประสงค์: Tabulate \(y\) across a range of \(x\) to locate sign changes (roots) and approximate maxima/minima.
ใช้เมื่อใด: Solving or sketching a function when you want to find where its graph crosses or turns.
ขั้นตอน
Enter the function in TABLE mode, set the start, end and step, then read where the sign of \(y\) changes or where it peaks.
ข้อควรระวังในการสอบ: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Statistics mode (mean, SD & regression)
Scientific calculator (e.g. Casio fx-991 series)
วัตถุประสงค์: Read the mean \(\bar{x}\) and standard deviation directly, and the gradient/intercept (and \(r\)) of a linear regression for bivariate data.
ใช้เมื่อใด: Any data-handling, statistics, or required-practical analysis question.
ขั้นตอน
Enter the data in STAT mode (1-VAR or A+BX), then recall \(\bar{x}\), \(\sigma\) or the regression coefficients.
ข้อควรระวังในการสอบ: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Carry exact values with Ans & memory
Scientific calculator (e.g. Casio fx-991 series)
วัตถุประสงค์: Keep full-precision intermediate values to avoid rounding errors.
ใช้เมื่อใด: Multi-step calculations where premature rounding loses the final accuracy mark.
ขั้นตอน
Use Ans, STO/RCL or the M+ memory to reuse the unrounded result of each step; round only the final answer.
ข้อควรระวังในการสอบ: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Equation solver — to CHECK your working
Scientific calculator (e.g. Casio fx-991 series)
วัตถุประสงค์: Use the built-in EQN/SOLVE mode to verify roots of quadratics or simultaneous equations you have already solved by algebra.
ใช้เมื่อใด: As a check only, after solving by hand.
ขั้นตอน
Enter the coefficients in EQN mode (or use SOLVE) and confirm they match your worked solution.
ข้อควรระวังในการสอบ: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
ข้อผิดพลาดที่พบบ่อย
1highคะแนนที่เกี่ยวข้อง: 2Architecture of the CPU
Confusing the roles of Program Counter (PC) and Memory Address Register (MAR).
วิธีหลีกเลี่ยง: PC holds the address of the next instruction to be fetched; MAR holds the memory address currently being read from or written to. Remember: PC points ahead, MAR points to the current address buffer.
2highคะแนนที่เกี่ยวข้อง: 1Designing, creating and refining algorithms
Failing to label True/False or Yes/No paths on flowchart decision nodes.
วิธีหลีกเลี่ยง: Every decision diamond must have exactly two output paths, and they must be clearly labelled 'True'/'False' or 'Yes'/'No' to receive flow lines marks.
3mediumคะแนนที่เกี่ยวข้อง: 2Wired and wireless networks, protocols and layers
Stating that adding more network devices 'decreases bandwidth' of the transmission medium.
วิธีหลีกเลี่ยง: Explain that adding devices divides the available bandwidth among more nodes, or increases packet collisions/latency, but does not decrease the absolute bandwidth of the physical line.
Omitting correct string delimiters (quotes) when comparing string variables in pseudocode or code.
วิธีหลีกเลี่ยง: Ensure string literals are wrapped in quotation marks, e.g. writing direction == "left" rather than direction == left.
5highคะแนนที่เกี่ยวข้อง: 4Designing, creating and refining algorithms
Updating line values incorrectly or skipping loop steps in variable trace tables, causing off-by-one errors.
วิธีหลีกเลี่ยง: Trace code line-by-line systematically. Only update variables in the table when an assignment on that specific line number actually executes.
6mediumคะแนนที่เกี่ยวข้อง: 1Data types
Confusing 'casting' with general 'type conversion' when explicit casting terminology is requested.
วิธีหลีกเลี่ยง: Use the precise term 'Casting' and use functions like int(), str(), or real() to show explicit variable data type coercion.
7mediumคะแนนที่เกี่ยวข้อง: 1Secondary storage
Giving generic secondary storage hardware names like 'USB' or 'Hard Drive'.
วิธีหลีกเลี่ยง: Be precise with terms like 'USB Memory Stick' (or Flash Drive) and 'Magnetic Hard Disk Drive (HDD)' to meet specific marking criteria.
8highคะแนนที่เกี่ยวข้อง: 2Ethical, legal, cultural and environmental impact
Using generic descriptors like 'fast' or 'cheap' without comparative qualifiers.
วิธีหลีกเลี่ยง: Always use comparatives, such as 'faster transmission speeds' or 'lower cost per gigabyte' to secure descriptive marks.
9mediumคะแนนที่เกี่ยวข้อง: 2Data storage
Writing 'SELECT ALL' or 'SELECT *' in database queries when specific, target fields are requested.
วิธีหลีกเลี่ยง: Write only the exact field parameters requested, separated by commas (e.g. SELECT StudentID, TeamName). Use '*' only when all fields are requested.
10highคะแนนที่เกี่ยวข้อง: 2Defensive design
Using 'or' instead of 'and' when checking ranges in validation logic.
วิธีหลีกเลี่ยง: Use logical 'and' to define continuous range bounds (e.g., if height >= 40 and height <= 180). Using 'or' makes the validation statement logically redundant.