Scarica Human-Computer Interaction (HCI) Principles and Design Methodologies e più Slide in PDF di Neuroscienze solo su Docsity!
Lecture- 1
Computers: In a classical situation we have an interactive guide, but now the machines don’t have this (microwave, a washing machines etc..) We focus on active machines, computing, interaction. We need understand which factors that are important for humans and then use this, Also need to consider interfaces where several people cooperate on the interface complex social organizations. Need to model the human to model an interface: especially we need to to consider the emotions Less is more in an interface. Vannevar Bush introduced in the concept of internet and storing info. The bigger the manual, the worse the interface. Augmenting human intellect: a concept designing the interface based on “common knowledge”? Goal: improve interactions by making computers more usable and receptive to the user’s need. HCI vs ID: interaction design: ID: Design based on user experience for example, and it should he completed as soon as possible. HCI: optimize the usability. The default was changed from no to, yes? And the number increased rapidly, there are tricks done to get outcome you want. Goal of HCI: Need to design interfaces given constraints implement the interfaces and make predictive models for the interface. The design of the of the object should be sufficient, it should not be a manual on how to use it. Things to be aware of:
- need to be consistent on the way your present data.
Lecture- 2
Usability:
To which extent a product extent a product can be specified users to reached specified goals with effectiveness, efficiency and satisfaction a specified context of use. Specified goals: the users needs and goals should be studied and defined carefully. Context of use : for example in a house; outside etc.… Usability goals / dimensions:
- Effectiveness: Does the system allow the user to fully reach the goal how accurate is it?
- Efficiency: How many resources have to be spent for getting the result. Is the system fast to use??
- Satisfaction: is the system enjoyable to use, do the user appreciate them?
- Learnability: How easy to learn?
- Memorability: use of system easy to remember.
- Safety: Protect user from dangerous conditions and undesirable situations. By preventing (don’t put exit button to save button). The goals vary in importance:
- Depence on the user
- but no user is uniformly novice or expert.
→Your senses store info in the short-term sensory store. Perception: You use your prev. memory to recognize the objects around you. This goes to the cognitive processor around you this goes to the cognitive processor which is used to perform and action (ex-sit down on a chair), the path planner uses the working memory to perform a task. This is a memory that we don’t remember for a long time. If we repeat the task it might be a part of the long-term rehearsal. Ex. Hit a ball, both brain and body lean. Working memory also uses long term memory to perform a task, because it uses pre-known info (ex. How to sum) Then the motor processor is instructed and performs a movement with the muscle which gives a feedback to the senses. A loop is looped many times. Perception: What one perceives isa result of interplays. Between past experiences, including culture. And the interpretation of the perceived. Web-Fechner law: logarithmic relationship between physical magnitudes of stimuli and perceived intensity. Ex. Small stimuli of light → make a change → will be perceived. High simuli many on strong colors → make a change → not perceived as easily. Kind off; sensors are saturated so the change is cumbersome. The stronger the stimulus. The less sensitive we are to percept the changes. Sensory modalities: Law of specific nerve energies: Signals are transmitted through our nerves. Where they have their own specific nerve energy →meaning multimodality : humans communicate through several channels , we then use this info, process it together to get a full “picture” of what we perceive meaning if you only see the lip movement, you don’t get the full meaning, only ex 5%. We want to design interface where we integrate as many sensors as possible ,which will increase the capability of the communication. Teams is not multinodular since It is just reproducing the video since it is just reproducing the video and voice to another channel. The human is the multimodal system in this case, not the system itself. The system itself needs to be the one combining the different sensors.
Multimodal System: microphone + video integrated together, meaning it receives the inputs and fusion these together and give out an output. Need to try to combine these together. Tries to understand and analyses the input input channels to extract more important info (higher abstract, ex, emotions). Sensory modality: The sensory channel. That the info is perceived. Type of communication channel. The channels have specific receptor cells tuned to be sensitive to different forms of physical energy in the environment. The sensory modalities are not processed in isolation. Motion sickness. Different parts of the body percept information contradicting to each other, causing the sickness. Multimodal areas exist in critical and subcritical areas: parts that control other organs. This integration important for allowing the brain to reconstruct internal body models and internal representations. Proximal and distal stimuli:
Lecture- 3
Listen: To perceive by the ear. Can get much info by the sound you perceive. Highest temporal resolution of all senses. The eyes has a resolution of 100ms. The ears have a resolution of 1-2 ms. Give information about the surrounding environment. The fastest way to get attention of a human is to use an auditory stimulus. The hearing system is capable to distinguish between sounds in a sound-scape. Physical apparatus:
- Outer ear: protects inner and amplifies sound.
- Middle ear: transmits sound waves as vibration to inner ear.
- Inner ear: Chemical transmitters are released and cause impulses in the auditory nerve. Two ears gives perspective, 3D dimensional effect and depth. Perceived and objective qualities of sound: Pitch: sound freq. Loudness: amplitude. Timbre: Type of quality. Objective: can be measured, the physical feature. Subjective: The perceived features. Sound: changes in the air pressure (Vibrations) The air Vibrations are picked up by eardrums → transformed to nerve impulses in the inner ear: done by the cochlea. In fluid: the propagation of the sound is better. Sound intensity: sound pressure: I = p.v [w.m^-2] p: sound pressure. v: particle velocity [ms^-1] The physical attribute of the sound that you can measure. Loudness: Perceived sound intensity. Used to arrange sound as quiet → loud
If you want to hear 60 dB at 10Hz you need to rise the volume to be able to hear it in the same intensity. Intensity: decibel, here 60 dB Auditory window: focus on only one auditory signal; f.ex vocal, drums etc. Pitch: harmonic sounds (tones, possible to sing). Some sounds do not cause a sensation of pitch: tromelyd, noise. And some sounds in between. Range of the pitch : 20Hz – 20khz. The pitch is perceived on a logarithmic scale: Sound 2x as high → frequency 2x as high. The frequency components called partials amplitude. White noise:
The hand: the output response of each receptor decreases over time (= Stimulation adaption). Hand is poorer then eye and better than ear in spatial details. Ear, hands and eyes complete each other Multimodal integration. Haptics: Kinesthesis: Perception of body movement: Can detect/ where is the arm.
Lecture- 4
How sensorial info is transformed to higher-level representations…. Several theories. Behaviorism: How the human reason. Deny consciousness: no reasonable thinking. Chains of conditioned reflex explain all learned behavior. Problem with solving works with trying and failing and then from this. Gestalt Psychology: Emphasis on dynamics and “holism”: a grouping of element such that the whole is greater than the sum of its parts. Law of pagnanz: the fundamental principle of gestalt perception. Gestalt perceptions:
- Law of closure: We tend to complete incomplete objects to perceive them a whole;
- Law of Similarity: We tend to similar sets as one group
- Law of Continuity: We tend to complete non completed lines.
- Law of Symmetry: We tend to favor symmetry Objects: If one part of face is unsymmetrical, we if may appear unsual.
- Law of Proximity: We tend to perceive group of objects with same distance as a group of objects.
- Law of closure: We tend to perceive objects moving with same rate as one group. Cognitive Psychology: Denies That perception and behavior are controlled by stimuli. It is rather based on general background knowledge and logic. Capacity toward interactive action = knowledge (in this case).
Lecture- 5
UI: user interface takes 50% of design times, impl time maintenance time and code size. The waterfall model has high risks of failing and we therefore use iterative design: We have an initial design, we implement it and then we evaluate, then repeat in a loop. Meaning that to obtain one version of the software, the loop should have been iterated many times, not only one iteration. Spiral model: One type of iterative design. We start in the middle and the radius represents the amount of resources used → in the middle : low cost / resources, at the end; high amount of resources. Early iterations use cheap prototypes. i.e they can be thrown away. For example pencil & paper;
- Because you don’t about colors, fonts, etc If you use paper and pencil you can ignore these factors and you confuse/distract the user with many factors.
- You only want to show the main interface; the guidliness of how to use the interface Need the user to focus on a higher level than a lower level of detail.
- Don’t want to waste resources and time on something that is going to be thrown away. Afterwards we use richer implementations when the risks are minimized. Either have several users to evaluate and analyze. Or we can predict. User centered design: Users are the center of the design process. An iterative design processes. Early Focus on users and tasks: user’s analysis: who the users are, task analysis: what they need to do, they are involved as evaluators, consultant, and designers. There are also constant evaluations throughout the iterations: users are involved in every iteration. Every prototype is evaluated. User Analysis: Important says something about their situation e.g., physical, and social context, if they are alone, together etc.: which sensory channels they have etc. You can create a persona: a fictious character used to specific representative of user class. This creates a sort of empathy making it easier to design regarding the right user, instead of for yourself. Personas are typically stereotypes. May also be risky and therefore we can add “color” to make it a real person. How to do user analysis:
- Questionnaires: used for getting characteristics.
- Interviews with users.
- Observation of users performing tasks. Task analysis: Aim: Identify the single tasks of the program. Each task should be expressed as a goal: what needs to be done, not how user hierarchical decomposition:
- Think about the overall problem the programs need to solve
- Then decompose it in subtasks Usually performed with interviews with users or direct observations. For each task this should be obtained:
- The goal- what needs to be done
- predictions
- subtasks Domain analysis: Dicovers the elements of the domain and how they are related to each other. First step is to identify the entities: People, objects, etc. Second step: determine important relations between the things. Finally: multiplicities of the thing are identified. Domain helps giving feedback to task / user analysis.
Lecture- 6
Design guidelines: Guidelines are heuristic and can be vague and contradictory. When initializing a game; the usability is the highest priority. Afterwards we focus on the user experience meaning that we need to challenge the user, not minimize the time to perform a task → don’t want to optimize the usability. Design Patterns: When using a solution repeatedly. DP are good solution to common problems and are therefore raised. These have been named and codified. They have already been tested and could therefore be used directly. For instance, widgets: scroll bar, button etc. Advantages: reuse code, shorter development time and greater reliability. Disadvantages: May constrain designer’s thinking. You rather use “constrained” wigdets instead of directly manipulating in the interface (F.ex zoom with touch) screen instead of using a widget. Errors in user interfaces: Fault: an element in the program not corresponding to expectations. Failure: The code in not conforming to specifications. Errors in user interfaces: Does not care about the correctness of the software application. To most common errors: slip and lapse: Slip: Failure of execution or control, ex click above the button you indeed to click on. Lapse: failure of memory: forgetting the overall goal or where you are in the procedure.
Mistake Vs slip & lapse: Need to distinguish between these. Cognitive behavior:
- skill-based: learned procedures, ride a bike.
- rule based, starting a car, changing gear.
- knowledge-based: problem solving with logic, if the does work need to figure out why it stopped Mistake: error in rule based or knowledge – based behavior , applying a rule in a situation where it should not apply/ using a faulty reasoning. Slips / lapses are common than mistakes. Capture & Description slips:
- Capture: you have two actions that starts the same way and then you continue with the wrong one. Ex. You type “qb” instead of “ab”.
- Description: Two actions are very similar. The user intends to do one action but accidentally substitutes the other. Lapse: Could happen due to interruption, often targeting the shorten memory. Also if the actions. Mode error: States of the interface: mode ex. Edit. Often slips, ex. If you press caps lock in paint, all the modes changes and you do different actions than intended. Avoiding slips:
- avoid actions with similar descriptions. Avoid lapses.
- Don’t distract the user with unnecessary interrupts.
- choose the last action as the most important to complete the task
- keep procedures short. Avoiding mode errors:
Lecture- 8
Problem: Design a cloud-based service s.t. people can share photos/movies etc. Where to start:
- Ask users about their current experiences with sharing files and examine the existing tools. Think of how to design the new service based on this. Next: The process of interaction design: how to design an interactive product?
- understand the problem space – formulated the problem in a way that can be solved buy interaction design, understand the users and problems they will face.
- Four basic activities of interaction design.
- A simple lifecycle model for interaction design. The two diamonds represent a process of exploring an issue more widely (Divergent thinking) and then taking focused action (convergent thinking). Discover: Helps understand the problem not assuming what the problem is. Talk to people etc. Define: Define the problem, analyze the current solutions. Don’t identify a problem with technology. The info from discovery phase helps defining. Look at solutions, skills, tech etc. Converge at a problem definition.
Develop:
- Create several solutions Develop → delivery: End up with one solution and develop protype. Travel organizer: Activity: Apply the double - diamond of design to produce an innovative interactions product for you own use: travel organizer exercise. First three phases: Produce an initial design using sketches, showing the main activity, both big on computer and small on phone. Reflect:
- what did you do first?
- what was your first instinct to do?
- Do you have experience to base your design upon? Understanding the problem space: Explore:
- Current user experience?
- Why need of change?
- how will the change improve the situation? Common: Starts designing the physical interface and what tech and interaction style to use (voice, AR etc) Can lead to potential users and contexts to be misunderstood. Usability and user – experience may be overlooked. 4 approaches to interaction design: . User centered: User knows best and is the and is the guide for the designer. Designers role = translate user’s needs and goals into a design solution. . Activity centered: focus on the behavior surrounding tasks. Users role are still important, but rather their behavior than their goals and needs. . System designs: The system (people, computers, objects) are at center of attention. For complex problems. Design teams benefit when being made up by people with diff backgrounds – will produce more and diverse solutions. User may be too focused on a known solution and don’t understand the need for a new sw. Importance of involving users: Users centered approach is based on:
