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Q1: Describe the special interface needs of children, older adults, and people with disabilities.

Making the web more accessible for users with various diabilities is to great extent a matter of using HTML the way it was intended ,to encode meaning rather than appearance. As long as a page is coded for meaning , it is possible for alternative browsers to present that meaning in ways that are optimized for the abilities of individual users and thus facilitate the use of the web by disabled users.

Visual Disabilities

In order to facilitate scanning it is recommended to emphasize the structure of the page by proper HTML markup: use

for the highest level heading,

for the main parts of the information within the

s, and

and lower levels for even finer divisions of the information. By doing so, the blind user can get an overview of the structure of a page by having the

s and

s read aloud and can quickly skip an uninteresting section by instructing the screen reader to jump to the next lower-level heading.

Most people already know about the use of ALT attributes to provide alternative text for images, though there are still many Web pages without ALTs. Some accessibility specialists advocate so-called described images, where text is provided to verbalize what a seeing user would see. For example, the Web Access Symbol shown above might be described as "a glowing globe with a keyhole." In my opinion, such literal descriptions are fairly useless for Web pages unless the user is an art critic. I much prefer utility descriptions that verbalize the meaning or role of the image in the dialogue.

In addition to completely blind users, there are many users who can see but have reduced eyesight. These users typically need large fonts which is a standard feature of most Web browsers. To support these users, never encode information with absolute font sizes but use relative sizes instead. For example, when using Style Sheets, do not set the font-size attribute to a number of points or pixels but set it to a percentage of the default font size. By doing so, your text will grow or shrink as the user issues "text larger" or "text smaller" commands and the initial appearance of the page will match the user's preferences.

Full support of users with reduced eyesight would require pages to look equally well at all font sizes. Doing so is often not practical, and it might be acceptable to make pages look slightly worse at huge font sizes as long as the basic page layout will still work. It is recommended to test pages with the default font set to 10, 12, and 14 point to ensure that the design is optimal for these common font sizes and then to make additional checks with default fonts of 18 and 24 points to make sure that the design still works at these accessibility-enhancing sizes.

Auditory Disabilities:People who are deaf or have other auditory disabilities rarely have problems on the Web since sound effects are usually totally gratuitous. The usability of a site almost always stays the same when the sound is turned off. With the trend toward more multimedia this is not going to remain the case, though. In particular, transcripts should be made available of spoken audioclips and videos should be made available in versions with subtitles (which will also benefit users who are not native speakers of the language used in the video).

Motor Disabilities

Many users have difficulty with detailed mouse movements and may also have problems holding down multiple keyboard keys simultaneously. Most of these issues should be taken care of by improved browser design and should not concern content designers except for the advice not to design imagemaps that require extremely precise mouse positioning. Client-side imagemaps will work even for users who cannot use a mouse at all: the browser should be able to move through the links under keyboard control.

Cognitive disabilities

Users with dyslexia may have problems reading long pages and will be helped if the design facilitates scanability by proper use of headings as noted above. Selecting words with high information content as hypertext anchors will help these users, as well as blind users, scan for interesting links (no "click here", please).

Q2: Describe how the principle of consistency can be applied to interface navigation, display organization, and data entry

There are many aspects to achieving consistency within your user interface. Here are 5 things you can look at to improve consistency in your designs:

choice of language

The language you use in both marketing copy as well as the wording used throughout the user flow can not only influence your users perception of your product, but also be a point of confusion when you use different terminology to represent the same thing. This concerns not only in the terms you choose but also the tone in which you convey your message.

2. Apply UI Elements as They are Originally Defined

UI elements that are commonly used, such as message windows, menu bars, icons, scrollbars, and radio buttons, are graphic elements that are typically consistent and have representations that are widely understood by users. For instance, radio buttons are meant to be used when there is only one option allowed. Checkboxes on the other hand should be used only when the user is allowed more than one option. In many ways, we can see how HTML5 beat out Flash technology as of late 2014. One of the reasons is arguably the ease of application and ease of use that developers, designers, and users can enjoy as a result of HTML5s consistency and standards in defining their UI elements.

3. Consider Various Well-established Conventions When Deciding on Layout.

It is certainly debatable whether a designer should copy how other people lay out their websites or apps. However, when you design with the users perspective and cognition in mind, it is important to understand that humans have a strong memory for where things are visually located on the screen. You should leverage this characteristic by reserving commonly used locations for various graphical elements such as having the logo on the top left, search field on the top right, exit icon on the top right, etc.