2. SEMANTICS BASICS

Question 1

Assistive technology:

Answer 1

These are tools that are designed to help users whose impairments can prevent them from accessing information technology at all.

Question 2

Screen readers:

Answer 2

A screen reader is a software application that enables people with severe visual impairments to use a computer.

Question 3

¿What is assistive technology?

Answer 3

Assistive technology is an umbrella term for a broad range of devices, software and tools that help any person with a disability complete a task.

Question 4

¿What are affordances?

Answer 4

An “affordance” refers to the possibility of an action on an object; for instance, we say that an elevator button affords being pressed, and a chair affords being sat on.

Question 5

¿What are affordances for?

Answer 5

Well designed affordances enable people to do something with as little training as possible.

Question 6

Affordances Examples

Answer 6

1. This date field means I should enter the US date.
2. A check box is a yes or no option.
3. Here, I see I can enter one line of text.
4. Radio buttons mean I can choose one option.
5. And this button here lets me know it will perform an action.

Question 7

¿What is to express the semantics of an element?

Answer 7

Is the need we have to make sure that information is expressed in a way which is flexible enough to be accessed programatically by assistive technology. Which can then create an alternative user interface to suit its users needs.

Question 8

¿What does screen reader does?

Answer 8

Instead of a visual UI, the screen reader provides an auditory interface. A screen reader actually largely creates the user interface for the user based on the programmatically expressed semantics.

Question 9

¿What information will the screen reader express?

Answer 9

role, name, state, and value:

1. Sometimes a screen reader might simply state the element’s role.
2. Other times it might play an easily recognizable sound
3. To avoid constant repetition. Sometimes it might do both.
4. The screen reader will announce an elements name, if it has one.
5. It will announce what its value is, if it has one.
6. And it will also announce any information it has about an element’s state.

Question 10

¿Whats I the goal with screen readers users?

Answer 10

Just provide enough information for the screen reader to use. Creating a kind of API describing the page structure.

This is more or less what the browser actually does present to the screen reader.

Question 11

¿What is the accessibility tree?

Answer 11

It is a modified version of the DOM tree made by the browser into a form which is useful to assistive technology.

Question 12

About elements names

Answer 12

We need to make sure that we’re making elements name discoverable. Provide text alternatives for any non text content.

But please keep in mind that in the context of role, name, value, and state, the name means the same thing.

Question 13

¿Which are the two types of labels?

Answer 13

1. Visible labels: which are used by all users to associate meaning with an element.
2. Text alternatives: are only used when there’s no need for visual labels. A text alternative is usually not visible on the pag.

Question 14

¿how to create visible and non-visible labels?

Answer 14

Check web aims checklist

Question 15

About text alternative images

Answer 15

We need to think about what role an image plays in the page to work out what type of text alternative it should have.

Question 16

¿What is a usablw text alternative?

Answer 16

In order for a string to be a usable text alternative it needs to convey the same thing as the image in the given context.

Question 17

A way to check whether alt text is sensible:

Answer 17

Imagine all your images are broken. ¿Can you still understand the page content?

Question 18

Names you don’t want to be pronounce by screen reader:

Answer 18

Use an empty alt text to remove the image from the accessibility tree.

Question 19

¿Which images should have an alt attribute?

Answer 19

All images should have an alt attribute.

Question 20

¿Which images should have descriptive text?

Answer 20

Important images should have descriptive alt text that just describes what the image is.

Question 21

¿Which images should have blank alt text?

Answer 21

Decorative images should have blank alt text. The screen reader will skip them.

Question 22

¿What happens if I don’t include blank text?

Answer 22

The screen reader may try to read the filename and if the file names weird, it’ll sound weird.