VCE Software Development flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Functional requirement

A statement of a behaviour or service the system must provide, such as calculating a total or sending a confirmation email, expressed as something testable.

Non-functional requirement

A quality constraint on the system rather than a behaviour, covering performance, usability, security, reliability or portability, usually stated with a measurable target.

Cohesion

The degree to which the tasks inside a single module belong together and serve one purpose. High cohesion makes modules easier to understand, test and reuse.

Coupling

The degree of interdependence between modules. Low coupling is preferred because a change in one module then has little effect on others.

Use case

A description of how an actor interacts with a system to achieve a goal, listing a main success scenario plus alternate and exception flows.

Context diagram

A top-level data flow diagram showing the whole system as one process, surrounded by external entities and the data flows crossing the boundary.

Unit testing

Testing a single module or function in isolation, often with stubs or drivers, to confirm it behaves correctly before integration.

Acceptance testing

Testing performed by or for the client to confirm the delivered system meets the agreed requirements and is fit for release.

Algorithm

A finite, ordered set of unambiguous steps that transforms input into output and terminates for every valid input.

Binary search

A search on sorted data that compares the target with the middle element and discards half the remaining range each step, giving O(log n) comparisons.

Linear search

A search that examines each element in turn from the start until the target is found or the data ends, requiring O(n) comparisons and no ordering.

Recursion

A technique where a function calls itself on a smaller input, requiring a base case that stops the calls and a recursive case that moves toward it.

Pass by reference

A parameter-passing method where the callee receives the address of the argument, so changes made inside the function affect the caller's variable.

Stack

A last-in-first-out data structure where insertion (push) and removal (pop) both occur at the same end, the top.

Queue

A first-in-first-out data structure where items are added at the rear (enqueue) and removed from the front (dequeue).

Big-O notation

A notation describing the upper bound on how an algorithm's running time or memory grows with input size, ignoring constants and lower-order terms.

Boolean AND

A logical operator whose result is true only when both operands are true; in pseudocode it is often written as AND or &&.

Validation

Checking that input data satisfies rules such as range, type, length or presence before it is processed or stored.

Primary key

An attribute or minimal set of attributes that uniquely identifies each row in a relation and cannot contain null values.

Foreign key

An attribute in one table that references the primary key of another table, enforcing referential integrity between related records.

First normal form

A relation is in 1NF when every attribute holds a single atomic value and no repeating groups or multi-valued fields exist.

Third normal form

A relation in 2NF with no transitive dependencies, meaning non-key attributes depend only on the key and not on other non-key attributes.

Referential integrity

A rule requiring every foreign key value to match an existing primary key value in the referenced table, or be null if permitted.

ACID

Four transaction guarantees: atomicity (all or nothing), consistency (valid states only), isolation (concurrent transactions do not interfere) and durability (committed changes persist).

SQL HAVING clause

A filter applied to grouped rows after GROUP BY, typically testing aggregate results such as COUNT or SUM, unlike WHERE which filters individual rows.

Incremental backup

A backup that copies only data changed since the most recent backup of any type, giving fast backups but slower restores that need the chain.

Gantt chart

A horizontal bar chart plotting project tasks against a calendar, showing duration, start and finish dates, dependencies and progress.

Critical path

The longest chain of dependent tasks through a project network; it determines the shortest possible project duration and has zero slack.

Milestone

A checkpoint in a project schedule marking completion of a deliverable or phase; it has zero duration and consumes no resources.

Risk mitigation

Actions planned in advance to reduce the likelihood or impact of an identified project risk, such as prototyping or keeping a spare resource.

Waterfall model

A sequential development model where each phase is completed and signed off before the next begins, with limited return to earlier phases.

Version control

A system that records each change to source files with author, time and message, allowing rollback, branching and parallel work.