Thread by @oedipusnj

Simple Rules for Providing Useful ALT

1/ ALT's sole function on Twitter's to provide an autonomous & as fully equivalent an experience of an image as possible for the blind/VI & neurodivergent

If you can see it/read it, I should be able to feel/hear it without leaving Twitter

2/ Image descriptions can be divided into two types:

1 descriptions of images of text, including charts, graphs, screenshots & diagrams

2 descriptions of purely visual images

Whenever posting an image of text, ALT's indispensable. Neither a screenreader nor a refreshable

3/ Braille display can read an image of text. It needs actual text.

Images of text also distort rapidly when magnified, quickly becoming unusable.

This is a critical problem for the majority of people who use ALT, for they are attempting to maximize what vision is available to

4/ them in order to both live their daily life & to interact with their devices

To do the latter, they use specialized programs that provide extremely high levels of magnification. They also rely on customized display settings in order to process information they cannot obtain

5/ without ALT.

Many neurodivergent individuals also use a similar strategy, employing ALT & customized display settings in order to successfully process images of text.

The use of images of text to avoid the hard character limit on tweets is the reason why the character limit

6/ on ALT is 1000 characters, & often even that is not sufficient, necessitating the break-up of the image of text into smaller images, each with appropriate ALT

Even though such tools as Google Lens & iOS' built-in LiveText make the extraction of text from images instantaneous

7/ the output still needs to be reviewed by a human, as formatting often interrupts the natural language flow of the content.

Be sure that the text makes sense when read from top to bottom uninterrupted, as that is how someone using a screenreader or Braille will experience it.

8/ As for purely visual images, there are two components to an equivalent: the "what" & the "why" of the image.

The "what" is a description of the contents of the image. While succinctness & clarity are always valued & appreciated, remember that image description is the

9/ digital equivalent of a curb cut or an access ramp in the real world. I need both, but I can't construct either myself. I need the person who chose to distribute the image to describe that image to me.

To have an equivalent experience, I need not only a description of what

10/ the image contains, but also a sense of the "why" of the image—the reason that image was chosen above all other possible images to communicate so eloquently to the viewer without the need for words

It is those unspoken words that you must explicitly articulate in your

11/ description. I cannot provide that information myself, & you—as the selector of the image—are best positioned to provide that information to me, from which I can construct a meaningful conception of what is being described

Each image will dictate how long a description is

12/ necessary. Each description should be as long as is a necessary to provide those who cannot visually process the image with an autonomous & equivalent experience of the post or thread of which is part.

To achieve that end, use rich descriptive language that does not depend

13/ on foreknowledge to evoke an image or feeling. Do NOT shy away from using color & other visual cues as part of your description, but do NOT limit your description to the visual plane & do NOT make your description dependent upon such knowledge.

Instead, incorporate into the

14/ description adjectives such as, "confidently" "lazily", "excitedly", "boldly" etc. as well as "small" & "large". Provide as multi-sensual & multi-dimensional a description as possible. The richer & more multi-sensory your language, the richer, more nuanced & much longer

15/ lasting the impression by your target audience will be

Don't hesitate to use color as a descriptor, but do not rely on it. The majority of people who use ALT will either have seen at some point in their lives or have some residual vision left. Only approximately 18% of us

16/ are stereotypically totally blind, like me.

In the US, 1 is considered legally blind & eligible for services if one's repaired visual acuity is less than 20/200, the point at which they take your driver's license away

Every experience of blindness is unique. It runs the

17/ gammut from nothing to base light/dark perception to blobs of color.

Some people have a strictly limited viewport, like constantly looking through a straw. Some people can only use their peripheral vision.

All of these individuals, are immeasurably aided by ALT.

18/x Here are Twitter's 3 main accessibility help docs. Note there is no longer a dedicated accessibility team at Twitter

1. How to make images accessible for people

help.twitter.com/en/using-twitt…

2. Close-captioning twitter videos:

help.twitter.com/en/using-twitt…

19/

3. Main twitter accessibility help file:

help.twitter.com/en/resources/a…

For a collection of accounts that use ALT creatively, consistently & in character with the nature of their account, please refer to my list, "The Art Of ALT"

twitter.com/i/lists/151372…

20/ If you would like examples of my own ALT, please consult #BCatPix, #TheArtOfALT & the account of the cat with whom is my honor to cohabitate, @BCatPix

21/ To enable a reminder like the "would you like to read this 1st" prompt to prevent tweeting without ALT

1 open Twitter Settings & Support
2 open Settings & Privacy
3 open Accessibility, Display & Language
4 open Accessibility
5 under Media enable image description reminder

22/ I realize this is a long thread, but it's a topic that needs a certain amount of specificity.

I hope you found this thread helpful. Please RT.

If you need more clarification or anything I wrote's ambiguous or confusing, please let me know. 😎

23/ With the termination of unlimited, free access to the Twitter API on April 29, 2023, valid, meaningful author-added ALT is more important than ever.

We'll no longer be able to extract text from images nor will anyone be able to add captions to videos that lack them via bot

24/ Please use ALT, & please spread the word that the vast majority of Twitter content is about to become inaccessible without free unlimited access to the API via accessibility bots

#SaveA11yBots

https://twitter.com/Oscar_Oscerlot/status/1633509408721313797