How do you judge whether a website works, is usable, and is accessible to everyone?
Test a website for functional correctness, and evaluate it for usability, accessibility and fitness for purpose.
A focused answer to the SQA Advanced Higher Computing Science content on web testing and evaluation, covering functional testing against requirements, usability, accessibility and fitness for purpose.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
The SQA wants you to test a website against its requirements and evaluate it on the criteria that matter for the web: not just whether it functions, but whether it is usable and accessible. Testing and evaluation close the web project, just as they do the software and database projects.
Functional testing
Functional testing confirms that each feature does what the specification says. As with any testing, you decide the expected result first and compare it with the actual result; a feature that "seems to work" but is never checked against a requirement proves nothing. You test across links, navigation, forms and any interactive behaviour, using normal data (a typical valid submission), boundary data (a field at its length limit) and exceptional data (a required field left empty), to confirm the site both accepts the right input and rejects the wrong input.
Usability
Usability is how easily and pleasantly a real user can accomplish their tasks. A usable site has clear, consistent navigation so users always know where they are and how to get elsewhere, readable text, logical layout, and feedback that confirms the result of actions. Usability is judged from the user's point of view, often by observing real users attempting realistic tasks.
Accessibility
Accessibility is whether people with disabilities can use the website. It is both an ethical and often a legal requirement, and it is distinct from usability: a site can be usable for most people yet inaccessible to a blind or motor-impaired user. Key features include alternative text on images (for screen readers), sufficient colour contrast (for partially sighted users), keyboard navigation (for users who cannot use a mouse), resizable text, and captions on video.
Fitness for purpose
Fitness for purpose is the overall evaluation: does the finished website meet every functional requirement from analysis, serve its intended audience, and work usably and accessibly across the devices its users have. It is judged against the original specification, so a clear analysis (the first topic of this area) is what makes a meaningful evaluation possible.
Try this
Q1. Name the accessibility feature that lets a screen reader describe an image. [1 mark]
- Cue. Alternative text (alt text) on the image.
Q2. State the overall criterion that asks whether a finished website meets its requirements and serves its users. [1 mark]
- Cue. Fitness for purpose.
Exam-style practice questions
Practice questions written in the style of SQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
AH style: accessibility4 marksExplain what is meant by accessibility for a website and give two features that improve it.Show worked answer →
Accessibility means the website can be used by as many people as possible, including those with disabilities such as visual, motor or hearing impairments (1 mark for the idea). Feature one: alternative text on images, so a screen reader can describe them to a blind user (1 mark). Feature two: sufficient colour contrast between text and background, so partially sighted users can read it (1 mark). A further mark is available for another valid feature such as keyboard navigation, resizable text, or captions on video (1 mark).
AH style: functional testing3 marksDescribe how you would functionally test a website's contact form against its requirements.Show worked answer →
Identify, from the functional requirements, what the form must do, for example send a valid message and reject an empty required field (1 mark). For each, decide the expected outcome in advance, then carry out the action and compare the actual outcome (1 mark). Test normal data (a complete valid message sends), boundary and exceptional data (an empty field is rejected with a message, an over-long entry handled), confirming the form behaves as specified in every case (1 mark). Markers want testing tied to the requirements with predetermined expected results.
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