Short Notes to Memorise (W1-8)

Professionalism in Practice

• Royal Charters: a formal document signed by the monarch for organizations with public interest objectives

• Professional Conduct: 4 aspects

• ACM Code of Ethics and Professional Conduct: states what computing professionals should do

System Development Lifecycle

• Systems Development Lifecycle (SDLC): process of determining how system can support business needs, designing, building, and delivering to users

• Stages of SDLC: Planning, Analysis, Design, Implementation (PADI)

• Waterfall Development: linear approach where each phase completed before next one

  • Pros: good for high security systems, easy task arrangement as 1 phase at a time

  • Cons: time-consuming, inflexible, no software until end

• Rapid Application Development: focus on rapid development and delivery

  • e.g. throwaway prototyping, iterative development

  • Pros: cheaper and easier, earlier user feedback, quicker delivery of software

  • Cons: planning hard, less documentation, hard to scale for large systems

Requirements

• Business requirement: represent overall goals of project

• User requirement: define what users need from system

• Functional requirement: specify what software should do and what info it needs to provide

  • e.g. “system must allow users to see previous 3 years order history, system must retain order info for 3 years”

• Non-functional requirements: describe characteristics system should possess, focussing on how functionality operates

  • 3 types:

    1. Product requirement: how product behaves (e.g. execution speed)

    2. Organisational requirement: policies and procedures (e.g. process standards)

    3. External requirement: e.g. legislative requirements

  • e.g. “it should take no longer than 2 seconds for user to get conformation for order, user must log in to password-protected area to gain order history”

• System requirement: detail how system should be built

• Requirements gathering: understanding what user wants or needs, and constraints

  • Methods include:

    • Questionnaires: scalable but no insight

    • Interviews: in-depth but time-consuming and biases

    • Observations: observe actual behaviours but time-consuming

    • Workshops: insights from multiple people at once but social desirability bias

• Requirement validation: ensure users understand and agree that specification accurately reflects their needs

  • (“are we building the right system?”)

• Requirement verification: check if requirements are correct

  • (“are we building it right?”)

Understanding Users

• Human-Computer Interaction (HCI): studying user interaction to improve usability

• User Experience (UX) design: enhancing overall user satisfaction and ease of use

• Techniques for considering users: scenarios and personas

• Usability: ensuring that interactive products are easy to learn, use and enjoyable from user’s perspective

• Nielsen’s Usability Engineering (1993): designing products that are easy and enjoyable to use by testing often, fixing problems fast and keeping real users in mind

• Nielsen’s Usability Characteristics: Learnability, Efficiency, Memorability, Errors and Safety, Satisfaction (LEMES)

• Evaluating Usability:

  • Expert evaluation: assessing system using guidelines or heuristics

    • Heuristic evaluation: experts check against usability principles

    • Walkthroughs: experts simulate user interactions

    • Standards/Guideline Checklists: review compliance

  • User evaluation: involves actual users

    • Observations, interviews etc.

• Nielsen’s Usability Heuristics:

  1. Simple and natural dialogue on interfaces

  2. Speak the user’s language, use simple terms

  3. Consistency with actions having same effect

  4. Feedback to users about their actions

  5. Shortcuts for experienced users

  etc…

  • Pros: quick, inexpensive, fast feedback, few ethical concerns

  • Cons: requires trained experts, may miss big issues when finding small issues

• Dark patterns: deceptive UI design features that mislead sers into making bad choices, by exploiting human weaknesses for service provider’s benefit

  • e.g. easy to subscribe to model but hard to exit, user see low price buut presented with higher price, user sharing more personal info than intended

Accessibility

• Digital accessibility: designing systems with disabled people in mind so they can interact with it similarly to others, regardless of physical or mental ability

• Social Model: asserts that disability is caused by societal organization, promoting independence, choice and control

• Medical Model: people are disabled due to impairments or differences, can lose independence, choice and control

• W5H

  • Who using it?

  • What they doing?

  • Where they do it?

  • When they do it?

  • Why they do it?

  • How they do it?

• Web Content Accessibility Guidelines (WCAG): provides technical standard for making web content more accessible to people with disabilities

• Web Accessibility Principles: Perceivable, Operable, Understandable, Robust (POUR)

Solving Problems

• Design ethnography: method that involves studying people in natural environment, earliest step in development lifecycle

  • Involves the usual stuff (observations. interviews etc.)

  • Having diverse number of personas and scenarios

  • e.g. wireless yoga mat: more experienced yoga people want more complex features, but less experienced yoga people want less complex features

• Participatory design: using users or participants to test products (or use personas or scenarios)

  • e.g. children using micro:bit: we can highlight concerns involving products

• Risk Mitigation Checklist: 4 risk zones, Authority and Discipline, Malevolence and Accidental Harm, Emotionality and Socialisation, Governance and Accounting

• Value-sensitive design: Designing a system that takes human values into account throughout the design process,

  • e.g. mental health tracker: symptom tracking to help and support a user’s wellbeing, or creating services that people can easily pick up and use, or designing the app to be easy to use, as well as being relaxing and soothing for the user to use

• Humble AI concept: promoting fairness and ensuring trustworthy people aren’t unfairly distributed

• Principle of Skepticism: assume AI is missing info for decision making, so seek additional data to reduce errors

• Principle of Curiosity: learn from borderline cases by testing different decisions, so it refines decisions and makes AI more accurate

Intellectual Property, Software Protection, Limiting Liability

• Intellectual property: any unique product that has commercial value

• Intellectual Property Rights (IPR): gives authors/inventors exclusive rights for a finite time, includes:

  • Copyright: governed by Copyright, Design and Patents Act 1988 (CDPA), owner has exclusive rights

  • Patents: protection for new inventions, full process required

  • Law of confidence: protects info like trade secrets or lists, used when idea not made yet

  • Design rights

  • Trademarks

• Digital Rights Management (DRM): access control mechanism used to restrict medium usage

• Digital Economy Act 2017: internet piracy set to 10 years, modifies CDPA

• Shareware: giving out free software so people would pay for an upgrade or donate

Professional Conduct, Legal Frameworks and Best Practice

• Data Protection Act (DPA): protects personal information from being misused by companies, organisations or government, lasted until 2018

• General Data Protection Act (GDPR): expanded rights for data subjects, including Right to be Forgotten and stricter obligations for organizations, 2018 onwards

  • British Airways didn’t comply with GDPR, fined £183 million

• Ai systems can exhibit bias

  • e.g. Amazon’s hiring tool penalizing CVs with word “women”

  • Facial recognition tools can target people of colour

  • BCS Code of Conduct emphasizes caring for wellbeing of others and potential harm from created systems