OpenLLM-France/wikimedia huggingface dataset:
# Models and Theories in Human-Computer Interaction/Norman's Affordances and Use in Design

The dictionary definition of affordance is “the qualities or properties of an object that define its possible uses or make clear how it can or should be used - We sit or stand on a chair because those affordances are fairly obvious.” Don Norman talks about affordances many times in his book “The Psychology of Everyday Things” while giving great examples.
Norman also talks a bit about perceived affordance. In design (web, mobile, etc) we care much more about what the user perceives than what is actually true. As a designer, we care about if the user perceives that some action is possible or not possible. Some perceived affordances in design include using conventional usage in imagery and interactions. For example, a progress bar on a website. The perceived affordance is to move from left to right but what if someone reversed that? Then it becomes confusing and users would be unsure of what’s going on.
Another good example of this is using words to describe the desired action. If something is a link instead of just underlining it use words like "click here" with the link or using action words on buttons like “Add” or “Import” versus something like “Next."
In the end what matters is if the desired controls can be perceived in an easy to use design and if the actions can be discovered (and not hidden) and whether standard conventions are used. It is possible to break some of these rules, but majority of the time these affordances should be followed for a useful site.
# Models and Theories in Human-Computer Interaction/Norman's Affordances
### Norman’s Affordances (Cindy Marinak)

Donald Norman’s The Psychology of Everyday Things discusses affordances, which are the perceived and tangible properties that provide clues to how an object works. Norman provides the example that a chair gives support hence affords sitting. Affordance is not only applicable to physical objects, but it is also applied to software design. (Norman 1988)
In software design, the raised style of a button or icon affords clicking. Similarly, the cursor changing from a pointer to a hand when the user hovers over a hyperlink, button, or icon provides a visual cue that the screen element is clickable.
In addition to affordance, the understanding of an object is interpreted by cultural factors, feedback, and the user’s mental model, which is formed through previous experiences. (Norman 1988) The aforementioned principles are also common considerations for software design. For instance, in an earlier class module, the cultural semantics of color were discussed specifically highlighting that red is interpreted differently by various cultures. (Carroll 2003) Teams localizing a software product may consider color, iconography, and screen layout (some cultures read right to left) among the factors that impact the user’s understanding of a design.
Practitioners’ consideration of visible cues; understanding of affordance; mental models of the target audience; cultural constraints inform design decisions that allow users to interpret how the object or design works.
Works Cited Carroll, John M. HCI Models, Theories, and Frameworks. San Francisco: Morgan Kaufmann Publishers, 2003. Norman, Donald A. The Pyschology of Everyday Things. New York: Basic Books, Inc., 1988.
# Models and Theories in Human-Computer Interaction/Norman's Affordances and Mapping

In Norman’s The Psychology of Everyday Things, he mentioned that affordance provide strong clues to the operations of things. When possible actions and consequences are easily figured out by first time users, it is very likely that this device or system is easy to use. Visibility is closely connected with affordance, so does mapping. To correctly understand the design or perform the operations, user need to rely on their mapping ability.
To my own experience, most of the time when there’re problems in design, mapping is one of the main causes. Mobile devices have bigger issues in the mapping and affordance, especially on small screen ones. Automobile dash board doesn’t have much trouble in this case as there are plenty room to display the controls. The mapping could be natural and clear.
On mobile device, there are not enough space to display all functions in most cases, so less important ones need to be hide under certain subcategories. Thus the visibility of affordance is not clear. On other cases, there are not enough space to display text labels. The labels serve as reminders if user forgets the functions. Latest app design tend to use just icons to represent meanings instead of icons plus text labels. Like the navigation bar of Instagram. This could be a big problem for older groups as the mapping is not clear to them. But I guess seniors are not the target group of Instagram, so they tend to do it their way to attract young people. Another mapping relates to users’ previous experience. Users may have been educated to behave in some way, so to make the mapping work, designers should follow that behavior. Through the usability study of an app I designed last semester, I found out that half of the users failed on the delete function. It is because they tend to drag the item to the trash can whereas my initial design failed to do so.
# Models and Theories in Human-Computer Interaction/Norman's Affordances and Principles of Design

I refer to and think of Norman's affordances and principles of design nearly every day at work and throughout the design process. Its easy to see that when a product is difficult to use it is violating at least one of these principles and these principles contribute to affordance. One of the issues with flat design today is that the designs lack affordance, button styles in Windows 8 don't stand out any more than other elements on the screens and there is nothing to really indicate that they are clickable. The button issue in Windows 8 could also easily be understood by answering the seven stages of action as design aids that Norman mentions. Many people could not tell what actions were possible on the screen, especially with hidden gesture controls and menus. These buttons could have been easier to understand by users by providing better affordance with improved visibility through some kind of visual indicator to make the button seem clickable. Creating a slightly different visual style from the rest of the screen with visual feedback that is consistent across all clickable buttons would also improve the conceptual model provided to the user.
However, I have noticed that Windows 8 doesn't seem to be quite difficult for most people to learn and that is something Norman doesn't really talk about. Even my 62 year old dad has been able to learn it fairly quickly. I posted many sticky notes around his monitor when he purchased a new computer thinking that he would have no idea how to turn it off, but he picked it up right away and had no need for the sticky notes. Does the time it takes to learn the product make a difference even if a design is initially bad according to the principles? In my opinion, everything is learnable which kind of makes everything usable whether its a good experience or not, but our goals as designers should be to make things as quick and easy to learn as possible.
# Models and Theories in Human-Computer Interaction/Norman's Affordances in Action

Norman's Affordances in Action (Tamara Sutton)
Norman’s book, The Psychology of Everyday Things, is one of my favorites that I enjoy referencing back to time and again. In his book he explains the importance of the affordance of “things”. Affordances being explained as the ‘perceived and actual properties of something’ and that they ‘provide strong clues of how things operate’. Items should be designed with visible parts that provide natural signals on how to they should be used.
This week I purchased a small 3 wheeled Radio Flyer scooter for a toddler’s birthday gift. My son who is 2 years old immediately investigated the scooter. I can’t recall if he had seen on before, and he doesn't have one. However, he was able to quickly figure out that the handles (much like those of a tricycle, big wheel and bike) were for his hands. He then climbed with both feet onto the footpad. He know’s from his bike that wheel’s are made for motion and after motioning with this body to get the scooter to move, he took one foot down to push the scooter. Within a minute of seeing the it, he was able to determine the correct way to use it.
This example displays how you take information from past experiences and quickly apply it as you perceive something new. My son knew that something wasn’t right when he had two feet on the footpad, the feedback he received was he was that he was not in motion. When he made an adjustment (taking one foot down to push on the floor), he received positive feedback because the motion was accomplished as a result of his action. It was fun to see the Norman principles in action with a two year old. It also displays a good conceptual model of the scooter. (It was indicated for children ages 2-5.)
References: Norman, D. (1988). The psychology of everyday things. New York: Basic Books.
# Models and Theories in Human-Computer Interaction/Norman's Principles of Design

In the first chapter “The Psychopathology of Everyday Things”, Norman elaborates on the 6 important principles of design including affordance, signifier, constraints, mapping, feedback (together making up discoverability principle) and conceptual model. As an interface designer, these six principles set up a consistent foundation for my design strategy across different products that I work on. I’d like to use the following examples that I found from my daily design tasks to reiterate the importance of these principles.
Affordance: Scrolling has been a very common practice for web pages. Just a small touch of covering the elements in the bottom of page provides a strong affordance to user that there is more content below and therefore it prompts user to scroll.
Signifier: As scrolling a page can be long and time-consuming task (infinite scrolling), having a small signifier like “Back to top” icon or button in the bottom of the page provides a quick way for user to move back up.
Constraints: Creating a UI kit provides good constraint for the design process of a product. It helps to avoid introducing new elements every time a new page/feature gets designed.
Mapping: In crowded interfaces such as a landing page or a dashboard, grouping together the elements that share a common theme/content/visual traits and arranging them in the hierarchy of importance provides a good natural mapping for users to digest through the information.
Feedback: The use of simple animation recently has been used more often in mobile applications as it provides instant feedback on every step user goes through to accomplish a task.
Conceptual model: As much as designers want to keep the design clean and simplified, having obvious spelled-out text for important tasks (versus using highly abstract icons) provides users immediate understanding of they are supposed to do.
# Linear Algebra/General Solutions

Suppose we have a general system of linear equations, and consider its basis columns by its coefficient matrix. Subtract the variables corresponding to those columns from both sides. The remaining variables can be solved using Cramer's rule using the determinants formed by its basis minor.
# Linear Algebra/Glossary
## A
### adjugate

    Also called classical adjoint. The matrix adj A formed from a square matrix A by replacing the (i, j)-entry of A by the (i, j)-cofactor, for all i and j, and then transposing the resulting matrix.

### affine transformation

    A mapping $T:\mathbb {R} ^{n}\rightarrow \mathbb {R} ^{m}$ of the form $T(x)=Ax+b$, with A an $m\times n$ matrix and b in $\mathbb {R} ^{m}$.

### algebraic multiplicity

    The multiplicity of an eigenvalue as a root of the characteristic equation.

### angle

    Between nonzero vectors u and v in $\mathbb {R} ^{2}$ and $\mathbb {R} ^{3}$. The angle $\vartheta$ between the two directed line segments from the origin to the points u and v. Related to the scalar product by $u\bullet v=\left\Vert u\right\Vert \left\Vert v\right\Vert \cos \vartheta$

## C
### coefficients

    A constant by which a variable are multiplied, fx. $2\,$ are a coefficient in the following equation $2x=4\,$.

### consistent linear system

    A linear system with at least one solution.

## E
### equivalent linear systems

    Linear systems with the same solution set.

### echelon form

    Also called row echelon form. An echelon matrix that is row equaivalent to the given matrix.

### echelon matrix

    Also called row echelon matrix. A rectangular matrix that has three properties: (1) All nonzero rows are above any row of all zeros. (2) Each leading entry of a row is in a column to the right of the leading entry of the row above it. (3) All entries in a column below a leading entry are zero.

## I
### inconsistent linear system

    A linear system with no solution.

## L
### linear equation

    An equation that can be written in the form $a_{1}x_{1}+a_{2}x_{2}+...+a_{n}x_{n}=b\,$, where b and the coefficients $a_{1},...,a_{n}\,$ are real or complex numbers.

### linear system

    A collection of one or more linear equations involving the same variables, fx. $x_{1},...,x_{n}\,$.

## R
### reduced echelon form

    Also called reduced row echelon form. A reduced echelon matrix that is row equivalent to a given matrix.

### reduced echelon matrix

    A rectangular matrix in echelon form that has these additional properties: The leading entry in each nonzero row is 1, and each leading 1 is the only nonzero entry in its column.

### reduced row echelon form

    See reduced echelon form.

### row echelon form

    See echelon form.

### row echelon matrix

    See echelon matrix.

## S
### solution

    A list $\left(s_{1},s_{2},...,s_{n}\right)\,$ of numbers that makes each equation in system a true statement when the values $s_{1},...,s_{n}\,$ are substituted for $x_{1},...,x_{n}\,$ respectively.

### solution set

    The set of all possible solutions of a linear system. The solution set is empty when the linear system is inconsistent.

### system of linear equations

    Also called a linear system, is a collection of one or more linear equations involving the same set of variables, fx. $x_{1},...,x_{n}\,$.
# Linear Algebra/General Systems

Consider the system of m equations
$a_{11}x_{1}+a_{12}x_{2}+a_{13}x_{3}+\ldots +a_{1n}x_{n}=b_{1}$ $a_{21}x_{1}+a_{22}x_{2}+a_{23}x_{3}+\ldots +a_{2n}x_{n}=b_{2}$ $a_{31}x_{1}+a_{32}x_{2}+a_{33}x_{3}+\ldots +a_{3n}x_{n}=b_{3}$ $\vdots$ $a_{m1}x_{1}+a_{m2}x_{2}+a_{m3}x_{3}+\ldots +a_{mn}x_{n}=b_{m}$
and the matrices
$A=\left({\begin{matrix}a_{11}&a_{12}&\cdots &a_{1n}\\a_{21}&a_{22}&\cdots &a_{2n}\\\vdots &\vdots &\ddots &\vdots \\a_{m1}&a_{m2}&\cdots &a_{mn}\end{matrix}}\right)$
$A_{1}=\left({\begin{matrix}a_{11}&a_{12}&\cdots &a_{1n}&b_{1}\\a_{21}&a_{22}&\cdots &a_{2n}&b_{2}\\\vdots &\vdots &\ddots &\vdots \\a_{m1}&a_{m2}&\cdots &a_{mn}&b_{m}\end{matrix}}\right)$

## Kronecker-Capelli Theorem

The general system of linear equations has a solution if the rank of A is equal to the rank of A$_1$, and has no solution if the rank of A is less than the rank of A$_1$.

### Proof

The system of linear equations has a solution only when the last column of A$_1$ is a linear combination of the other columns. If that is so, then by a theorem proven earlier, the column span of A is the same as the column span of A$_1$, so their ranks are the same. Now, suppose that their ranks are the same. Then the basis columns of A also form a basis column of A$_1$ since they have column spans of the same dimension. Thus, their column spans are the same, and so the last column also belongs to the column span of A, and so is linearly dependent on the other columns, this linear dependence is the solution to this system of equations. Suppose that the rank of A$_1$ is greater than A. This implies that Another proof is if we sopose that the rank of A is r, so if b is linear with {a1,a2....ar} it proof that the rank of {a1,a2...ar,b} is r,so the theorem is solved, But if the b is not combination with system (a1,a2.....ar),it means that the system (a1,a2...ar,b) is a base of system (a1....an,b), if we atach any ai/r<i<n,the system (a1,a2...ar,b,ai}is linear it mean that system (a1,a2.....ar,b)is a base of {a1,a2.....an.b),so the rank of (a1,a2.....an,b)is equal with Rank(A)+1. So we can not solve the system,
# Linear Algebra/Geometry of Determinants

The prior section develops the determinant algebraically, by considering what formulas satisfy certain properties. This section complements that with a geometric approach. One advantage of this approach is that, while we have so far only considered whether or not a determinant is zero, here we shall give a meaning to the value of that determinant. (The prior section handles determinants as functions of the rows, but in this section columns are more convenient. The final result of the prior section says that we can make the switch.)
# Neuroscience/Cellular Neurobiology

Cellular Neurobiology is the study of the brain from a cellular perspective; that is, a study of the properties of cells in the brain, and how cells interact and communicate. The interaction of these cells mediates identifiable functions of different systems in the brain, and the goal of the cellular perspective of neuroscience is to understand these interactions. Specific applications of cellular neuroscience include the mechanisms that produce the symptoms of neurodegenerative diseases such as Parkinson's or Alzheimer's.

### Topics

* Cells of the Brain
* Neuronal Membrane
* Action Potentials
* Synapses
* Neurotransmitters
* Nervous System Structure
* Somatic Sensory System
# Neurology and Neurosurgery/Stroke

Stroke (brain attack) is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.
# Neurology and Neurosurgery/Symptoms and Signs in Neurology

Signs and Symptoms of Neurological Disorders:
Alzheimer's Disease:
* Forgetfullness
* Dementia
Schizophrenia:
* Hears internal voices
* Delusions
* Hallucinations
* False personal beliefs
* Disorganized speech
# Neuroscience

Neuroscience is a field that is devoted to the scientific study of the nervous system.
Such studies may include the structure, function, development, genetics, biochemistry, physiology, pharmacology, and pathology of the nervous system. Traditionally it is seen as a branch of biological sciences. It can involve convergence of interest from many allied disciplines, including psychology, computer science, statistics, physics, and medicine. The scope of neuroscience has now broadened to include any systematic scientific experimental and theoretical investigation of the central and peripheral nervous system of biological organisms. The methodologies employed by neuroscientists have been enormously expanded, from biochemical and genetic analysis of dynamics of individual nerve cells and their molecular constituents to imaging gross representations of perceptual and motor tasks in the brain. Neuroscience is at the frontier of investigation of the brain and mind. The study of the brain is becoming the cornerstone in understanding how we perceive and interact with the external world and, in particular, how human experience and human biology influence each other.
* Search in this book
* Wikimedia Commons Neuroscience with files for this book
* How you can help contribute!
* List of contributors
* v:Fundamentals of Neuroscience- related Wikiversity course

## Contents

* Preface
* Cellular Neurobiology
* Neuroanatomy
* Developmental Neurobiology
* The Senses
* Neurophysiology (Electrophysiology)
* Neuropsychology
* Neuropsychiatry
* Cognitive Neuroscience
* Computational Neurobiology
* Neurobiology of Disease
* Sleep
* Glossary
# Neurology and Neurosurgery/Ischemic Stroke

Ischemic Stroke occurs when blood flow is blocked to a portion of the brain, resulting in the death (ischemia) of neurons in the brain. A blood clot can interfere with blood flow in the brain, by cutting off blood flow beyond a certain point and result in ischemia of brain tissue dependent upon the blood flow that is downstream from the occluding clot.
# Modern Meitei/Genders

Meitei language (Manipuri language) has nouns of only two genders, masculine and feminine. The names of menfolk and male gods are always masculine. The names of womenfolk and female gods are always feminine. A group consisting of people where both men and women are assembled together, is grammatically masculine (showing the signs of male dominated ancient society).
The grammatical genders are not always related to the actual real life genders. Non living things are usually considered as masculine but they can also be feminine in some cases. One can sometimes, but not always, infer the gender of a noun from its ending. If the noun ends with "ꯕ" ("-ba") or "ꯄ" ("-pa") or "ꯕꯥ" ("-bā" / "-baa") or "ꯄꯥ" ("-pā" / "-paa"), then it is usually masculine. If the noun ends with "ꯕꯤ" ("-bi" / "-bee") or "ꯄꯤ" ("-pi" / "-pee"), then it is usually feminine. For example, the term for man is "ꯅꯨꯄꯥ" ("nupa") and the term for woman is "ꯅꯨꯄꯤ" ("nupi").
# Modern Meitei/Greetings

Here, you will learn to greet people and ask how they are. You do not need any prior knowledge of Meitei.
Among Meitei speakers, the most popularly used greeting is "Khurumjari" (ꯈꯨꯔꯨꯝꯖꯔꯤ, /khoo-room-ja-ree/)(derived from Ancient Meitei term "Khulumchali"). It is used among respectable and honourable people. Khurumjari literally means "bowing or homage". In the Puyas (traditional Meitei religions texts), Khurumjari mostly occurs as a salutation to the deities. But the use and meaning have evolved. Today, among Meitei speakers, Khurumjari is a simple greeting to say "hello". Khurumjari is almost equivalent to Indo-Aryan terms like Namaste, Namaskar and Namaskaram.
Some important greetings are:
* How are you? : ꯑꯗꯣꯝ ꯀꯝꯗꯧꯔꯤ? (A-dom Kam-dou-ree) or ꯑꯗꯣꯝ ꯀꯝꯗꯧꯔꯤꯒꯦ? (A-dom Kam-dou-ree-gey)
* What are you doing? : ꯑꯗꯣꯝ ꯀꯔꯤ ꯇꯧꯔꯤꯕꯒꯦ? (A-dom Ka-ree Tou-ree-ba-gey)
* It's nice to meet you! : ꯑꯗꯣꯝꯒ ꯎꯅꯕꯗ ꯅꯨꯡꯉꯥꯢꯕ ꯐꯥꯎꯏ ꯫ (A-dom-ga Oo-na-ba-da Noong-ngai-ba Phaau-ee) or ꯑꯗꯣꯝꯒ ꯎꯅꯕ ꯅꯨꯡꯉꯥꯏ ꯫ (A-dom-ga Oo-na-ba Noong-ngai)
* How is it going?: ꯃꯇꯧ ꯀꯔꯝꯅ ꯆꯠꯊꯔꯤꯕꯅꯣ? (Ma-tou Ka-ram-na Chat-tha-ree-ba-no)
Other important greetings are:
* Good day. : ꯑꯐꯕ ꯅꯨꯃꯤꯠ ꯑꯣꯢꯕꯤꯌꯨ ꯫ (A-pha-ba Noo-meet Oi-bee-yoo)(literally, "Have a Good Day")
* Good morning. : ꯑꯐꯕ ꯑꯌꯨꯛ ꯑꯣꯢꯕꯤꯌꯨ ꯫ (A-pha-ba A-yook Oi-bee-yoo)(literally, "Have a Good Morning")
* Good afternoon. : ꯑꯐꯕ ꯅꯨꯡꯊꯤꯜ ꯑꯣꯢꯕꯤꯌꯨ ꯫ (A-pha-ba Noong-theel Oi-bee-yoo)(literally, "Have a Good Afternoon")
* Good evening. : ꯑꯐꯕ ꯅꯨꯃꯤꯗꯥꯡꯋꯥꯢꯔꯝ ꯑꯣꯢꯕꯤꯌꯨ ꯫ (A-pha-ba Noo-mee-daang-wai-ram Oi-bee-yoo)(literally, "Have a Good Evening")
* Good night. : ꯑꯐꯕ ꯑꯍꯤꯡ ꯑꯣꯢꯕꯤꯌꯨ ꯫ (A-pha-ba A-hing Oi-bee-yoo)(literally, "Have a Good Night")
* Good night (to sleep) : ꯐꯖꯅ ꯇꯨꯝꯃꯁꯦ ꯫ (Pha-ja-na Toom-ma-sey)(literally, Let's sleep well) or ꯃꯪ ꯐꯔꯁꯦ ꯫ (Mang Pha-ra-sey)(literally, Let's have good dreams)
# Modern Meitei/Foods and Drinks

* the food - ꯆꯥꯅꯕ, ꯑꯆꯥ ꯑꯊꯛ, ꯆꯥꯅ ꯊꯛꯅꯕ, ꯑꯆꯥꯄꯣꯠ
* the menu - ꯆꯥꯅꯕꯒꯤ ꯄꯔꯤꯡ, ꯑꯆꯥ ꯑꯊꯛꯀꯤ ꯄꯔꯤꯡ, ꯆꯥꯅ ꯊꯛꯅꯕꯒꯤ ꯄꯔꯤꯡ, ꯑꯆꯥꯄꯣꯠꯀꯤ ꯄꯔꯤꯡ
* the waiter - ꯆꯥꯅꯕ ꯁꯤꯜ ꯂꯥꯡꯕ ꯃꯤ, ꯑꯆꯥ ꯑꯊꯛ ꯁꯤꯜ ꯂꯥꯡꯕ ꯃꯤ, ꯆꯥꯅ ꯊꯛꯅꯕ ꯁꯤꯜ ꯂꯥꯡꯕ ꯃꯤ, ꯑꯆꯥꯄꯣꯠ ꯁꯤꯜ ꯂꯥꯡꯕ ꯃꯤ
* the bill/the account - ꯁꯦꯟꯐꯝ
* the bread - ꯇꯜ/ꯇꯟ
* the salad - ꯁꯤꯡꯖꯨ
* the alcohol/beer/rum/whiskey/wine - ꯌꯨ
* the milk - ꯁꯪꯒꯣꯝ
* the yoghurt - ꯁꯪꯒꯣꯝ ꯑꯐꯝꯕ
* the fish - ꯉꯥ
* the meat - ꯁꯥ
* the tomato - ꯈꯥꯃꯦꯟ
* the olive - ꯆꯣꯔꯣꯐꯣꯟ
* the fruit - ꯎꯍꯩ
* the honey - ꯈꯣꯢꯍꯤ
* the sugar - ꯆꯤꯅꯤ
* the salt - ꯊꯨꯝ
* the dish/the plate - ꯄꯨꯈꯝ
* the breakfast - ꯑꯌꯨꯛꯀꯤ ꯆꯥꯅꯕ
* sweet - ꯑꯊꯨꯝ ꯑꯍꯥꯎ
* the knife - ꯊꯥꯡ
* the napkin - ꯇꯩꯊꯣꯛꯅꯕ ꯐꯤ
* the glass/the cup - ꯈꯨꯖꯥꯢ
* bitter - ꯈꯥꯕ, ꯑꯈꯥꯕ
* acidic/sour - ꯑꯁꯤꯟꯕ
* the soft drink - ꯊꯛꯅꯅꯕ