Interfaces Humano-Computador - Aula 01 - Conceitos Fundamentais

Introduction to Human-Computer Interaction

Fundamental Concepts of Interfaces

• The lesson begins by exploring the concept of interfaces, questioning how many interfaces individuals interact with daily. Examples include waking up to an app interface and using online learning platforms.

• An interface is defined as a boundary between two different systems. In computing, it exists between human and computational systems, facilitating communication.

• The user interface (UI) is described as the computational support that allows users to access system functions and receive necessary information.

Elements of User Interface

• The UI consists of hardware elements (like screens and touchpads) and software components responsible for presenting information and managing interactions.

• Software related to UI includes programs that manage how information is displayed and how users can interact with devices.

Understanding Interaction

• Interaction in human-computer contexts is likened to a dialogue or language exchange, requiring specific elements for effective communication.

• Unlike natural languages, which humans are inherently designed to understand, computer interaction relies on artificial constructs that must be learned by users.

Language of Interaction

• The discussion introduces the idea that computer interaction has its own lexicon consisting of symbols with meanings (e.g., notification icons).

• Syntax in this context refers to valid actions within the interface; not all clicks will yield results based on contextual validity.

• Semantics relates to the meaning behind actions taken within the interface, such as signaling danger through specific commands.

Design Principles in HCI

• Effective design is crucial in creating user interfaces. It involves understanding user needs and ensuring products meet those requirements effectively.

Interaction Perspectives in Human-Computer Interaction

Different Perspectives on Computer Interaction

• The designer can create various interactions, such as making the computer a conversational partner, exemplified by Amazon Alexa, which uses natural language to follow commands.

• Another perspective views the computer as a tool, similar to using a text editor where different instruments are combined for a desired outcome.

• A further perspective positions the computer as a medium for communication between humans, illustrated by interfaces like WhatsApp that prioritize user interaction over the technology itself.

Understanding Affordances in Design

• Affordances refer to design characteristics that indicate how an object should be used. For example, door handles suggest pulling or pushing based on their design.

• An effective affordance guides users intuitively; for instance, input fields in Google prompt users to enter information due to their visual cues.

Quality of Interaction: Historical Perspective

Defining Quality in Interaction

• The concept of quality is challenging to define but easy to observe when present or absent. ISO 8402 defines it as the totality of characteristics that satisfy explicit or implicit needs.

• Quality is dynamic and evolves over time based on user perspectives and experiences with systems.

Evolution of User Expectations Over Decades

• In the 1940s and 50s, quality was associated with functional adequacy and system availability due to frequent failures impacting user outcomes.

• By the 1960s, with mainframe usage rising, users began prioritizing utility and performance from systems for specific tasks.

• In the 1970s, with automation systems emerging, quality became linked to intelligibility and reliability—critical for complex operations like those in aircraft cockpits.

Shifts in User Demographics and Usability Concepts

• The 1980s saw a shift towards personal computing and graphical interfaces. This change introduced diverse user categories including educators and home users seeking more intuitive interactions.

Understanding Usability and User Experience

Defining Usability

• Usability is defined by a prominent author in human-computer interaction as comprising five key elements:

• Ease of Learning: The easier an application is to learn, the higher its usability.

• Efficiency: Greater efficiency in task completion enhances usability.

• Memorability: Users should be able to return to the interface without retraining.

• Error Rate: Fewer errors lead to better usability.

• Subjective Satisfaction: Users must find the experience enjoyable and pleasant.

Evolution of Usability Concepts

• The advent of the web in the late '90s significantly transformed usability concepts:

• It expanded studies from professional systems to include general users who create and consume content online.

• With universal access, new characteristics emerged:

• Communicability: Users understanding designers' intentions.

• Navigability: Ease of finding information on websites.

Interaction Quality in Modern Contexts

• By the early 2000s, interaction quality began incorporating aspects like:

• Portability: Accessing information across various devices.

• Responsiveness & Accessibility: Systems recognizing user context (e.g., location).

Multi-Dimensional Quality of Interaction

• In the current decade (2010), interaction quality is recognized as multi-dimensional:

• New standards (ISO/IEC 25010) define usability through various qualities including recognition, operability, error protection, aesthetics, and accessibility for diverse users.

User Experience vs. Usability

• User experience (UX) differs from usability; it encompasses emotional and cognitive responses during interactions with products or technology:

• UX reflects personal experiences shaped by individual backgrounds and cultural contexts.

• UX includes two dimensions according to Rácio Zau's framework:

• Pragmatic Experience: Focused on achieving specific tasks (e.g., learning).

Understanding User Experience

The Motivation Behind Learning

• Being special motivates individuals to engage with their learning experience, such as attending a class at Univesp. This engagement is driven by personal desire rather than obligation.

Comprehensive User Experience

• User experience (UX) extends beyond just the interface of an application; it encompasses all points of contact a user has with the system, including interactions with stores, manuals, and support systems.

• The formation of user experience is holistic, involving 360 degrees of interaction from initial interest to eventual disposal or upgrade of the application.

Temporal Nature of Experience

• User experience evolves over time; it begins before using a product and continues through various stages of usage—initial use, sporadic engagement, and ongoing interaction.

• Designing for user experience requires considering all moments throughout the product lifecycle rather than focusing solely on immediate usability.

Distinguishing Usability from User Experience

• Usability is an intrinsic characteristic defined by designers within a product. In contrast, user experience is subjective and influenced by individual perspectives and external factors.