B2.1 · Adapt a program template to a specification

Ontario Grade 11 Computer Science

Software Development

ICS3U study topic B2.1

What you will learn

• Explain what a program template and a specification provide.
• Identify the required inputs, processing, and outputs in a specification.
• Adapt existing code by changing only what is needed to meet stated requirements.
• Trace a program’s variables and compare its expected result with the specification.

1. Read the specification before editing

• Specification: the stated requirements for a program.
• Template: existing program code used as a starting point.
• Map each requirement to input, processing, or output before editing.

2. Make a focused adaptation

• Use the specification to decide what to change.
• Trace the actual values through the adapted code.
• Check expected output against the stated requirements.

3. Check whether the adaptation meets the request

• Check every requirement, not just whether the program looks complete.
• Keep the adaptation focused on what was requested.
• Distinguish stated requirements from assumptions.

4. A practical adaptation routine

• Read, map, inspect, adapt, trace, and compare.
• A trace table records expected state; it does not report an actual run.

Trace for the kilometre conversion

Worked example

Replace a sample value with required input

name = input("Name: ")
print("Hello, " + name + "!")

1. Identify the mismatch
   The template’s fixed sample value does not meet the requirement to ask for a name. Keep the greeting, but replace the fixed value with input.
2. Trace the input
   For this trace, the user enters Mira. The input statement stores that text in name; the next statement combines it with the greeting.
3. Derive the output
   The displayed line follows from the traced value. It is the expected output for this input, not a report of running the program.

Worked example

Adapt the calculation and label

kilometres = float(input("Kilometres: "))
metres = kilometres * 1000
print("Distance in metres:", metres)

1. Compare template and requirement
   The conversion factor from kilometres to metres is 1000, so multiplying by 100 does not meet the requested conversion. Keep the input and display structure, but correct the calculation.
   $$1\text{ km} = 1000\text{ m}$$
2. Trace the calculation
   The input text is converted to a number and stored in kilometres. Multiplying by 1000 gives the value stored in metres.
   $$3.5 × 1000 = 3500$$
3. Check the display
   The label identifies the result as metres, matching the specification. The expected line is derived from the traced value.

Worked example

Add a required summary to a template

first = int(input("First score: "))
second = int(input("Second score: "))
total = first + second
print("Total:", total)
print("Scores recorded.")

1. Keep what already meets the specification
   The template already receives two whole numbers and calculates their total. Those parts match the requirements, so they can remain.
2. Add the missing output
   The specification also requires a particular message. Add a display statement for it rather than changing the calculation.
3. Trace the values
   The first input is stored as 6 and the second as 8. Adding these values gives 14, which the program displays before the required message.
   $$6 + 8 = 14$$

Common mistakes and how to avoid them

Lesson summary

• A template is a starting point; a specification describes the program’s required behaviour.
• Map requirements to input, processing, and output before editing.
• Preserve parts of the template that already match, and change the parts that do not.
• Trace inputs and variable values to derive expected output, then compare it with the specification.

Check your understanding

Key terms

Program template

Existing program code provided as a starting point for changes.

Specification

A description of what a program is required to do.

Trace

Follow the program statements and record the values and expected output for chosen input.

Continue through ICS3U

View the complete ICS3U Ontario Grade 11 Computer Science curriculum and lessons

• B1.3 · Plan a solution using an input–process–output model
• B2.3 · Design reusable program parts
• B1.1 · Choose problem-solving strategies for different tasks
• B1.2 · Solve problems alone and in a team
• B2.5 · Design a usable software interface
• B3.1 · Design simple array algorithms to a specification

About this lesson and its review

Published by DoAssignment. This reviewed lesson follows Ontario Grade 11 Computer Science (ICS3U), expectation B2.1. It is a study resource, not an official curriculum publication.

Before publication, content is checked for structure, mathematical or chemical notation, calculations, course boundaries, and readability. Errors can still occur, so corrections are welcomed.

Official curriculum reference

Report a correction or ask a question