SS 1 Second Term

Lesson objectives

By the end of the week, learners should be able to:

1. Name three translator types: interpreter, compiler and hybrid.
2. Explain why an interpreter reports errors line by line.
3. State why a compiler produces a single executable file.
4. Describe hybrid translators combining compiler and interpreter strengths.
5. Match translator types to their characteristics.

Key vocabulary

• Translator: a programme converting one language into another.
• Interpreter: converts line by line and executes immediately.
• Compiler: converts the whole program into executable code at once.
• Hybrid translator: combines interpreter and compiler approaches.
• Line-by-line: processing one command at a time during execution.
• Executable file: a file ready to run without further translation.
• Characteristic: an attribute describing a translator.

Common misconceptions

• "Every translator behaves the same." Interpreters and compilers differ fundamentally in error reporting.
• "An interpreter cannot handle errors." An interpreter reports errors as it runs line by line.
• "Compilers run slower than interpreters." Compilers run faster after the one-time translation cost.

Teacher activities

1. Starter: run a broken interpreter program and show where the error appears; then show the same broken program through a compiler.
2. Name the three translator types and demonstrate the difference on a live system.
3. Explain why an interpreter reports errors line by line rather than batch.
4. Explain why a compiler produces a single executable file.
5. Introduce hybrid translators and compare them with pure interpreter and pure compiler.
6. Close with the characteristic-matching task and exit question.

Student activities

1. Observe the starter and explain how the interpreter found the error quickly.
2. Name the three translator types in their own words.
3. Explain why an interpreter reports errors line by line in one paragraph.
4. State why a compiler produces a single executable file in one sentence.
5. Describe hybrid translators in one sentence.
6. Match the three translators to their characteristic descriptions.

Practical / learning evidence

A three-translator chart comparing characteristics, plus a translated program through an interpreter and through a compiler with expected outputs. Hand in both for marking.

Resources and preparation

Computers with a BASIC interpreter and a compiler installed, blank windows and sample broken programs. Disable Caps Lock before typing. Preload both translators in read-only folders for learners lacking installation.

Assessment for learning

Inspect the characteristic chart for three distinct descriptions. Compare the interpreter and compiler outputs for matching behaviour. Ask a learner to describe the hybrid approach. Flag any learner who claims translators behave identically.

Inclusion and homework

Provide the chart prefilled for learners who need scaffolding and allow oral matching. Extend confident learners with four translators and a second hybrid example. Homework: name one advantage and one disadvantage of interpreting versus compiling.