Proximity

[lauracarlson]

Proximity

User Needs

I need close proximity of items such as labels and controls, calls to action within my view, and to be informed of new information outside my view.

Important Terms

Field of Vision

The entire area that can be seen when the eye is directed forward, including what is seen with peripheral vision. For more information consult Field of Vision.

Point of Regard

The area that the user is viewing. For more information consult Point of Regard.

More terms and definitions are available in the Glossary.

Description

People with limited field of vision or who use large text have little in their field of view at one time. Beyond browser zoom people, may use screen magnification software and may only see a small portion of the screen. Others may not have field loss and simply look closely at the screen, which limits the field of view.

If related information is not close together, they can have trouble knowing about it, seeing it, and using it. Items near each other are more likely to be perceived.

Note: This guidance is about visual proximity. We may do audio guidance relating to audio separately.

Examples

1. Distant Proximity

The following is an example of distant proximity between form controls and labels. Space is not used to group related content. A large space exists between the labels 'Email', 'Phone', 'Voice', 'TTY' and their form controls.

2. Distant Proximity and the Effect on Point of Regard

When related form controls and labels are not in close proximity, they are likely to be outside of a person's point of regard. The following diagram shows point of regard as small circle. Within the point of regard, the labels 'Email' and 'Phone' are visible. But not their form controls. In addition, 2 radio buttons are visible without labels.

3. Close Proximity

The following is an example of closer proximity between form controls and labels. Space is reduced and used to group related content. The contact form shows close proximity of the labels 'Email', 'Phone', 'Voice', 'TTY' and their form controls.

4. Close Proximity and the Effect on Point of Regard

When related form controls and labels are in close proximity, they are more likely to be inside of a person's point of regard. The following diagram shows the point of regard is a small circle. The labels: Email, Phone, Voice, and TTY are next to their form controls inside of the point of regard.

What To Do

• Have calls to action within the point of regard.
• Reduce space used to group related content.
• Use visuals such as a shared background and dotted lines to group related content.
• Use vertical layouts.
• Locate labels immediately before form fields that are not radio buttons or checkboxes.
• Locate labels immediately after radio buttons and checkboxes.
• Left justify required indicators, hints, and disclosure symbols in left to right languages.
• Locate an item close to an item it is most related to, and less close to a less related item.
• Separate unrelated content.

How it Helps

• When related content is in close proximity, it is more likely to be inside of the point of regard.
• Because low vision can make it difficult to scan right to left, vertical blocks are easier to see.
• Positioning labels for form fields that are not radio buttons or checkboxes makes those labels easier to locate with a screen magnifier since they are immediately before the field and also can be found in a vertical column (when the start of the fields line up vertically).
• If a field has data in it, it is easier to understand or check the data if one reads the label first and then the content rather than the other way around.
• Checkboxes and radio buttons have a uniform width while their labels often do not. Having the radio button or checkbox first therefore allows both the buttons and the labels to line up vertically.

Quick Checks

Straw Test

A good test that can help unearth layout and design challenges for people with low vision is the straw test.

Take either your left hand or your right hand and hold it up like you're holding on to a straw. And I mean like, not a milkshake straw but one of those little coffee stir sticks. Hold it up like you're making a fist and look through. Make the straw as tiny as you can. Close your other eye.

Now looking through the straw examine your web pages and interfaces. Go through task flows while looking through the straw with your other eye closed. For instance, go through the motions of filling out a form while you're looking through the straw. It can particularly challenging and is very easy to lose context.

A video that includes a straw test is available.

Zoom Your Browser

Set your display to 400%. Check that all content and functionality remains available.

Related WCAG

• G162: Positioning labels to maximize predictability of relationships
• SC 1.4.10 (Related to horizontal scrolling text)
• SC 1.4.12 (Related to text spacing)

Related UAAG

• UAAG point of regard definition
• UAAG SC 1.8.6 Maintain point of regard

Related Accessibility Requirements for People with Low Vision

• 3.6.2 Proximity of Related Information

"…point of regard is the area that the user is viewing. In user interface generally, proximity is about using space to group related content and separate unrelated content."

Editorial Notes

This is a first draft of the Proximity section for LVTF supplemental guidance.

notes here

[Myndex]

Good solid beginning, I particularly like all the example graphics.

Some thoughts on points that might be added:

• There is some obvious overlap with cognitive... how should we be addressing that? Just a link if coga has something related?

• As a matter of design, and this addresses vision and coga, is proximity per relatedness. That is, an item needs to be close to the item it is most related to, and less close to a less related item. If we break it down to four or five basic categories, we end up with these — by no means exhaustive. These categories are only for the purposes of determining proximity priorities.

CATEGORIES OF PROXIMITY

DIRECT

• Direct: an inseparable association, such as a label and the specific element it labels. There are two sub categories, Direct On where the elements may substantially overlap and Direct Adjacent where the elements are close or touching, but never overlaping.
• Direct On
  • The text on an action item or button.
  • The "play" triangle on a media control
  • Information/coding associated with a given target, such as the flight number and the radar blip of that specific aircraft.
  • The enumerated tick marks for a slider control, or the value display for that slider
  • The placeholder text on a form field (has special requirements)
• Direct Adjacent
  • The specific value of a radio button (or checkbox) with the specific button, like the "text/tty" radio in the above example.
  • The label for a specific field in a form, such as "name" and the entry field for name.
  • The identifier of an inline link such as an underline or ref number
  • The extra optional text added adjacent for an icon, specific to that icon only.
  • The caption for an image.
  • The spinner for a spoiler or drop down
  • A series of clickable page numbers, and the left/right arrows.

RELATED

• Related: a closer relationship than grouped, but not as close as direct.
  • The label for the entire radio button stack and their individual labels
  • A subset of elements of a larger form, such as the name and address elements as a tighter related subgroup.
  • The name for a control like a slider, that has other direct information associated (like a value display or enumerated tickmarks.)
  • The value display for a slider that has enumerated tickmarks
  • The other buttons in a media control, like fast forward.
  • The other menu items in one drop down menu
  • The radio button related to another field or selector, such as a radio for "home" or "work" adjacent to a form field for phone number.
  • The label "page" for the collection of page number selectors.
  • The cancel X on a dialog and the dialog

ANTI-RELATED

• Anti Related: items that should never be near each other. These items may exist in the same group or may be in separate groups. Anti-related items have certain special rules as well.
  • The SAVE and the DELETE button
  • The RESET FORM and SUBMIT button
  • The ACCEPT and CANCEL buttons

GROUPED

• Grouped: A top level grouping of sub groups.
  • All the elements of the same form, inclusive of all the related and direct subgroups.
  • A form and its explanatory text
  • All the controls in a nav bar
  • All the items in a menu
  • All the media controls and the viewer itself.
  • The main article's headline, sub heads, article page nav, article images/captions
  • A dialog box with a close X upper right, other accept or cancel buttons, the message

UNRELATED

• Unrelated: while on the same page, one might assume some relationship. In this context it means part of a different group, or having a different function serving different needs or goals.
  • Advertisements vs any other content
  • The footer group vs the article group
  • The left nav bar vs the clickable article page numbers

PROXIMITIES and INTERFERENCES

The idea with the above groupings is to highlight the need for closely/directly related elements to be very close or connected, and related but not immediately to be close but far enough to provide the needed visual separation for cognitive clarity and to prevent crowding. For instance, the label "name" on the name entry field needs to be close to that field, but noticeably farther away from the next closest field to make it clear as to which field it is directly associated with.

With proximity is the potential for interference, and interferences can be dealt with through priorities, or in HTML/CSS terms stack order and z-index.

• Direct is the highest priority

  • Highest z-index.
  • Stacked with or grouped together in an enclosing element for only those 2 or 3 direct items.
  • Uses HTML or CSS built-in associations (such as the label element)
  • Direct On items should ideally not exceed the bounding object
    • Rules for text readability and padding still apply
  • Direct Adjacent items should have the closest visible proximity (except of course for Direct On items).
    • Non-text Direct items can touch or overlap it appropriate.
    • Text items still abide by rules of padding
    • As a rule of thumb, Direct Adjacent items are spaced at half the visible distance as "related" items.

• Related is the second priority

  • As a rule of thumb, twice the distance from a Direct relation as those direct items are to each other (assuming the Direct items are appropriately very close).
  • No interference with Direct relations.
  • Second highest z-index
  • As Direct items are each in granular sub-groups, those sub-groups are then siblings in a related group, such as the name, address, city, phone fields in a subgroup of contact info as part of a larger form.
  • Sub group labels for controls or forms that have smaller Direct sub groups.

• Anti-related

  • Keep "consequences" controls separated, particularly from high use controls.

• Unrelated items or subgroups should have visually more separation than related items. As a rule of thumb, twice that of related items or four times that of direct items.

EXAMPLE:

[lauracarlson]

Hi @Myndex,

Thanks, Andy! Much appreciated. Some great ideas that should be incorporated.

I'm not sure how detailed we we want to get. Thoughts @mraccess77, @shawna-slh, and everyone?

Thanks again,
Laura

[Myndex]

Hi @lauracarlson

Thanks, Andy! Much appreciated. Some great ideas that should be incorporated.
I'm not sure how detailed we we want to get. Thoughts @mraccess77, @shawna-slh, and everyone?

Thanks Laura,

Well for the main document certainly not the whole lists — I put in long lists so we have something to select from.

Thinking: 2 from DirectON, 3 from Adjacent, 3 from Related, 1 from Anti-Related, 2 from Grouped and 2 from unrelated.

I think it's more important that the specified proximity and interference ratios/distances be well described.

Perhaps start with 𝜱 (phi) as one suggested minimum ?

Or some number like it. Phi is nice because it scales well, and the values work well as relative units.

z = 𝜱^-1/𝜱 = 0.382 to start, then 1.618 * z for each step up the related chain.

For the sake of argument, example using rem:

adjacentMargins: 0.382rem
relatedMargins: 0.618rem
groupedPadding: 1rem
unRelatedMargins: 1.618rem
antiRelatedMargins: 2.618rem

So each more distant relation is separated by an additional 162% of the previous relation spacing.

Square root of 2 (1.414) is another useful sequence, but tighter overall:

adjacentMargins: 0.5rem (tighter is 0.3536)
relatedMargins: 0.707rem
groupedPadding: 1.0rem
unRelatedMargins: 1.414rem
antiRelatedMargins: 2.0rem

[mraccess77]

Hi Laura, I think this is very helpful.
An additional situation to clarify is that beyond browser zoom there is screen magnification software where you may only see a small portion of the screen. Also even if people don't have field loss - simply looking closely at the screen limits the field of view.

Placement of controls in expected locations like text to the right of checkboxes can also help as screen magnifiers may pan the view with the checkboxes on the left side of a magnified area. Magnification software may predict which area to show by control type.

I've run into issues with disclosure symbols that are right aligned when the text is on the left and I didn't even realize the headings could be expanded because I missed the symbol.

We have a technique related to predicted locations that we can include:
https://www.w3.org/WAI/WCAG21/Techniques/general/G162.html

Finally it might be worth noting that this needs to be considered in different responsive variations as well.

One note from Andy's response - we might consider that keeping labels and fields closer will help people to differentiate between which label a form field applies to. Ideally we would work toward an non-ambiguous situation, I'd say this aspect is secondary though to the primary one that you have described. We could do another guidance for proximity of other things feedback, etc. or try to include it here.

[lauracarlson]

Hi Jon (@mraccess77),

All great information that should be incorporated.

Thank you!

Laura

[shawna-slh]

Ooops, we got overlapping discussions. See #108 (which I am closing)

[allanj-uaag]

Wanted to chime in on Jonathan's point about issues with right alignment of controls. I have also seen alignment issues on forms where the hint or required indicator is right justified in a label ...too far away when you are focused on the left justified part of the label. At one time the right justification was present in the pattern library US gov. web standards. It has since been fixed - everything is in close proximity. e.g. Name * [ ] Jim

…

On Wed, Nov 3, 2021 at 3:50 PM Jonathan Avila ***@***.***> wrote: Hi Laura, I think this is very helpful. An additional situation to clarify is that beyond browser zoom there is screen magnification software where you may only see a small portion of the screen. Also even if people don't have field loss - simply looking closely at the screen limits the field of view. Placement of controls in expected locations like text to the right of checkboxes can also help as screen magnifiers may pan the view with the checkboxes on the left side of a magnified area. Magnification software may predict which area to show by control type. I've run into issues with disclosure symbols that are right aligned when the text is on the left and I didn't even realize the headings could be expanded because I missed the symbol. We have a technique related to predicted locations that we can include: https://www.w3.org/WAI/WCAG21/Techniques/general/G162.html — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#133 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABX5ML63XCK7X6OH7WFDYXTUKGVB7ANCNFSM5GTKLC4A> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

-- TSBVI Need assistance? Click this link for help: MOJO HELP DESK <https://tsbvi.mojohelpdesk.com/mytickets/create#/ticket-form-selection> Jim Allan, Accessibility Coordinator Texas School for the Blind and Visually Impaired 1100 W. 45th St., Austin, Texas 78756 voice 512.206.9315 fax: 512.206.9452 http://www.tsbvi.edu/ "We shape our tools and thereafter our tools shape us." McLuhan, 1964

[lauracarlson]

Hi Jim! (@allanj-uaag),

Great example. Thank you!

Laura

[mraccess77]

Sam: Visuals also play a role such as a shared background, dotted line, group.
Andy: avoid absolute measure and use relative.
Andy: is there a way to indicate when things are off-screen to look in that area.

[mraccess77]

Hi @lauracarlson

• For the user with 20/200 vision it may be helpful to clarify that their viewing distance to the monitor is reduced which effectively limits their physical view of the page. We give examples of browser zoom, screen magnification, etc. but folks may be wondering why this might impact a user even if they are not using those.

For "Problem: When a form's required indicator is right justified, I miss seeing it." I'd suggest we explain because the magnified view only shows a portion of the browser viewpoint at any one time.

For Shopper with low vision using browser zoom Problem: When I add an item to my shopping cart, I am not alerted of the total update." I'd explain because the shopping cart icon is not within the point of regard where I added the product because I am zoomed in with the browser.

[lauracarlson]

Hi @mraccess77,

I added your excellent suggestions.

Thank you!

[sdw32]

Generally speaking this looks great, one minor point on terminology though, from a couple of minutes Google searching, I don't think the point of regard is a property of the user. You can talk about the users field of view, or focus of attention, or the point of fixation. The point of regard is the property of the website that relates to the bits of content that the user is focusing on. However the point of regard is a property of the user agent, rather than something that the user has.
I didn't find any reference to the phrase 'point of regard' outside of WCAG, so my preference would be to avoid this term unless it is absolutely essential. The point of fixation or the focus of attention are both commonly used phrases I think.

[lauracarlson]

Hi Sam (@sdw32),

Thank you very much for checking the draft. It will be good to discuss the term "Point of Regard" at Thursday's meeting. If we change the term here, we likley should change it in our Requirements document too.

For reference, I did a search and found the following list of usage outside of W3C. Besides a few web and low vision uses the term seems to be used in eye-tracking, 3D and virtual reality.

1. "The 'point of regard' or 'focus area' is the area of a screen that a user is focusing on. If a user has low vision and needs to zoom in order to view content, that point of regard becomes focused on a much smaller area. If an action then alters that point of regard again, but only temporarily, it can cause the user to lose their place and become confused and frustrated." - Low Vision and Colour Blindness (Section 8), - Ashley Firth, 2019.

2. "Point of regard is a fancy way of saying 'the part of the app that currently has the user's attention'". - The Web and The Point of Regard - Sam Bleckley

3. "The point−of regard of each subject is measured while he finds the given target in the image of a Web page." - An Analysis of Point-of-Regard Measurment during Web Browsing (PDF) - Takafumi Uchida, Shino Iwashita

4. "point of regard (POR): Portion of the user interface to which the user is attending at present. More exactly, it is the accessible or part of accessible toward which the next LSR query or command will be directed." - LSR Web UI Specification - Peter Parente anf Scott Haeger

5. "In this paper, legibility of sentences on web sites was examined using a psychophysiological method, point-of-regard measurement, to obtain other practical data." - Legibility evaluation using point-of-regard measurement - Daisuke Saito, Keiichi Saito, Masao Saito.

6. "point of regard (PoR) or gaze direction" - Gaze and Eye Tracking: Techniques and Applications in ADAS - Muhammad Qasim Khan and Sukhan Lee.

7. "…most modern eye-tracking systems now use video images of the eye to determine where a person is looking (i.e., their so-called "point-of-regard")…" - Eye Tracking in Human-Computer Interaction and Usability Research: Current Status and Future Prospects (PDF) - Alex Poole and Linden J. Ball

8. "…where the subject is looking - the point-of-regard (POR) …" - Three-dimensional head motion, point-of-regard and encoded gaze fixations in real scenes: Next-generation portable video-based monocular eye tracking - Susan M. Munn

9. "A major obstacle in point-of-regard monitoring for human-computer interaction has been the contaminating effect of head movement. " - Simulation results for an innovative point-of-regard sensor using neural networks - A. I. Tew.

10. " In this paper, we propose to deal with the problem of point-of-regard estimation from low-quality images acquired by an integrated camera inside a notebook computer " - Cursor control by point-of-regard estimation for a computer with integrated webcam - Cristina, Stefania Camilleri, Kenneth P.

11. "The construction of a low cost fairly accurate recording equipment of visual point of regard is described. The technique is based on optical mixing on the head of cornea reflex and field of view." - A Versatile Recorder of Visual Point of Regard - Larsson, L E and Rumar, K.

12. Estimating point-of-regard using corneal surface image - Kentaro Takemura , Shunki Kimura , Sara Suda "…we propose a method that combines a scene image with a corneal surface image. We employ a corneal surface image to estimate the point-of-regard on a scene image. …"

13. "...The work presented in this paper builds on our earlier work, which addressed the problem of estimating on-screen point-of-regard from iris center movements captured by an integrated camera inside a notebook computer, by proposing a method to approximate the head movements in conjunction with the iris movements in order to alleviate the requirement for a stationary head pose... - On-screen point-of-regard estimation under natural head movement for a computer with integrated webcam - Cristina, Stefania Camilleri, Kenneth P.

14. "…In general, there are two types of eye movement monitoring techniques: those that measure the position of the eye relative to the head, and those that measure the orientation of the eye in space, or the "point of regard" (Young & Sheena, 1975 [PDF]). The latter measurement is typically used when the concern is the identification of elements in a visual scene, e.g., in (graphical) interactive applications… " Eye Tracking Techniques - Andrew T. Duchowski.

15. "Eye gaze tracking is a technique which is commonly used in human-computer interaction. By determining the eye gaze, the point-of-regard can be estimated by intersecting the gaze line and the target plane…" - Point-of-Regard Measurement via Iris Contour with One Eye from Single Image - Shang-Che Huang Department of Computer Science and Information Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan ; Yi-Leh Wu; Wei-Chih Hung; Cheng-Yuan Tang.

16. "…Information on the user's gaze or "point of regard" in an immersive 3D environment offers great potential…" - An Open Source Head-Eye Tracking Suite For Immersive Environments: Point of Regard (PDF) - David Morris, Karina Rodriguez-Echavarria, David Arno

17. "where the subject is looking -- the point-of-regard (POR)" - 3D head motion, point-of-regard and encoded gaze fixations in real scenes: next-generation portable video-based monocular eye tracking - Susan M. Munn

18. "Gaze localisation in space is one of the most hot and challenging topic in cognitive vision and in general in vision research as it attacks important issues such as atten- tion, feature detection, visual localisation, human-machine communication, and most of the factors concerning the hu- man response to surrounding visual stimuli" - A general method for the point of regard estimation in 3D space - Fiora Pirri, Matia Pizzoli, and Alessandro Rudi.

19. "…Point of Regard (PoR) head-eye tracking software uses an open source library which takes as data input a users' head position, head orientation and eye data from any device giving the freedom to the developer for manipulating the resulting combined data…" - An Open Source Head-Eye Tracking Suite For Immersive Environments: Point of Regard - David Morris, Karina Rodriguez-Echavarria, David Arnold.

20. "…depending on the depth of the viewer's point of regard (POR)…" Adjusting stereoscopic parameters by evaluating the point of regard in a virtual environment - Jessica Contia Benoit, Ozella, EricPaquette, and Patrice Renaud.

21. "…The overall gaze estimation model is general, as no particular complex model of the human eye is assumed in this work. This is made possible by a novel approach, that can be sketched as follows: each eye is imaged by a camera; two conics are fitted to the imaged pupils and a calibration sequence, consisting in the subject gazing a known 3D point, while moving his/her head, provides information to 1) estimate the optical axis in 3D world; 2) compute the geometry of the multi-camera system; 3) estimate the Point of Regard in 3D world…" - A general method for the Point of Regard estimation in 3D space - Fiora Pirri , Matia Pizzoli , Alessandro Rudi.

22. "…A wearable apparatus configured to acquire zoom images of a portion of an environment viewed by a user responsive to determining a point of regard of the use…" - Wearable point of regard zoom camera (patent) - David Cohen, David Mandelboum, Giora Yahav, Shai Mazor, Sagi Katz.

23. "…we propose a passive eye-gaze tracking method to estimate the point-of-regard (POR) on a monitor screen from lower-quality images acquired by an integrated camera inside a notebook computer…" - Cursor Control by Point-of-Regard Estimation for a Computer With Integrated Webcam (PDF) - Stefania Cristina and Kenneth P. Camilleri.

24. "The programming strategies developed for incorporating the viewer's point-of-regard are independent of proprietary eye tracking equipment and are applicable to general gaze- contingent virtual environment designs." - Incorporating the viewer's point of regard (POR) in gaze-contingent virtual environments - Andrew T. Duchowski

25. "…By uniting the line-of-sight convergence point and the size of the pupil, this model can be used to measure the 3D Point-of-Regard in free space…" - A Novel Method for Estimating Free Space 3D Point-of-Regard Using Pupillary Reflex and Line-of-Sight Convergence Points - Zijing Wan, Xiangjun Wang, Kai Zhou, Xiaoyun Chen, Xiaoqing Wang.

26. "Abbreviation is mostly used in categories: Gaze, Head, Lens, Technology." - POR means Point-Of-Regard - allacronyms.com

27. "System measures intersection of line of sight and eye point of regard /EPR/ for a human operator in visual scanning system." - Eye point-of-regard system - NASA.

[mraccess77]

From UAAG: https://www.w3.org/TR/2015/NOTE-UAAG20-20151215/#def-point-of-regard

The position in rendered content that the user is presumed to be viewing. The dimensions of the point of regard can vary. For example, it can be a two-dimensional area (e.g. content rendered through a two-dimensional graphical viewport), or a point (e.g. a moment during an audio rendering or a cursor position in a graphical rendering), or a range of text (e.g. focused text), or a two-dimensional area (e.g. content rendered through a two-dimensional graphical viewport). The point of regard is almost always within the viewport, but it can exceed the spatial or temporal dimensions of the viewport (see the definition of rendered content for more information about viewport dimensions). The point of regard can also refer to a particular moment in time for content that changes over time (e.g. an audio-only presentation). User agents can determine the point of regard in a number of ways, including based on viewport position in content, keyboard focus, and selection.

[Bhoomika-Bhagchandani]

This is very easy to follow. I only have a couple comments:

1. Could we include more specific examples of the issue/problem experienced by different personas that are relevant to their context/situation? For example, a university student experiences issues with filling out an admissions form or a professor experiences issues with filling out a student evaluation form. I like the shopper's example.
2. I think it may be useful to describe what having a 20/40 or 20/200 means in terms of what a person can or cannot typically see. This may help a sighted reader get a better perspective.
3. We mentioned having CTAs in the point of regard. Could we add CTAs in the screenshot examples as well to demonstrate the issue visually?
4. Would it be useful to hyperlink descriptions of UX/UI or assistive technology related terminologies used in the text?

[lauracarlson]

Hi @Bhoomika-Bhagchandani,

Thank you for the great comments. I added that the university student experiences issues with filling out an admissions form and the a professor experiences issues with filling out a student evaluation form.

I agree that example images of Calls to Action in the point of regard could be helpful.

We may want to consider a adding a LVTF glossary for all of the terms so that it can be linked to from all sections of the supplemental guidance. For now I added the terms you mentioned that need defining to the "Other Resources" section so that we don't forget them.

Thanks again!
Laura

[shawna-slh]

I agree that it is good to have different examples in some cases, and we might want that elsewhere. Given the purpose and audience of supplemental guidance, I think we want fewer User Need points. Maybe only one. And maybe with just the quote. (This would match what COGA has now.)

---

Background/rationale:

WAI resources generally have separate documents or sections for:

1. Understanding user needs – e.g., https://www.w3.org/TR/low-vision-needs/
2. Personas or user stories – e.g., overall user stories, COGA personas
3. Guidance for improving accessibility – WCAG, supplemental guidance, e.g., COGA find things

For #3, the goal of the user need is to provide a short persona quote that:

• helps readers understand why the guidance is important for users
• humanized the reason for the guidance
• show that it the design that causes the problem, not the user

For example, see in:

• COGA find things
• New in WCAG

More info: #142

---

We can decide to do robust personas if we want to separately. (Some notes on that: #119 )

[lauracarlson]

Hi @shawna-slh, and @mraccess77

I reduced the user need to one general one and updated things per the January 20, 2022 LVTF meeting. If I missed anything we discussed please let me know.

Thanks!

Laura

[bruce-usab]

Very nice proposal! My only suggestion is to include focus on historic threshold of 20/70.

One @@ is in regard to glossary of terms and need to define 20/40 vision, 20/200 vision.

20/70 vision means that the person can only make out details at 20 meters what someone with good vision would be able to discern at 70 meters. Note that 20/70 is a ratio, so the metric is also applicable to 20 feet and 70 feet.

Follows is an source we might borrow phrasing from: https://www.eeoc.gov/laws/guidance/blindness-and-vision-impairments-workplace-and-ada

The Centers for Disease Control and Prevention (CDC) define "vision impairment" to mean that a person's eyesight cannot be corrected to a "normal level." Vision impairment may result in a loss of visual acuity, where an individual does not see objects as clearly as the average person, and/or in a loss of visual field, meaning that an individual cannot see as wide an area as the average person without moving the eyes or turning the head. There are varying degrees of vision impairments, and the terms used to describe them are not always consistent. The CDC and the World Health Organization define low vision as a visual acuity between 20/70 and 20/400 with the best possible correction, or a visual field of 20 degrees or less. Blindness is described as a visual acuity worse than 20/400 with the best possible correction, or a visual field of 10 degrees or less. In the United States, the term "legally blind," means a visual acuity of 20/200 or worse with the best possible correction, or a visual field of 20 degrees or less. Although there are varying degrees of vision impairments, the visual problems an individual faces cannot be described simply by the numbers; some people can see better than others with the same visual acuity.

I will be looking for the sources cited in the above.

[lauracarlson]

Hi Bruce (@bruce-usab),

Thank you! I added 20/70 and linked your comment in the "Other Resources" section.

Laura

[bruce-usab]

Just to be pedantic, I don't think we need to define each ratio. But before I make an edit to the glossary which is the right term? I don't feel that "Ratio Measurement of Vision" is a good fit.

For now, any concerns for making "Visual Acuity" is the indexed term, and folding the CDC paragraph about visual impairment there?

OTOH, it might well make sense for 20/70 and 20/200 to be listed terms in the Glossary. If so, are they at the top or bottom? (I.e., how are we alphabetizing numerals?)

[shawna-slh]

A little thing:

Straw Test
A good test invented by accessibility advocate Derek Featherstone

Derek has done a lot of great things. However, he did not invent the straw test. Gregg Vanderheiden and I were doing that in training in the 1990s, and Gregg was probably doing it years before that. :-)

[lauracarlson]

Thanks, Shawn. I removed the reference to Derek.

[lauracarlson]

FYI: The LVTF does have a Glossary started in our Wiki.

[sdw32]

Visual acuity is the technically correct term for 20/70 and 20/200. I know this is nearly always defined in terms of how far away someone would stand compared to where someone with 'normal' 20/20 vision would stand. However I feel this definition is fundamentally flawed as there is no 'normal vision'. Actual measured vision is typically in the range 20/15-20/25. The technically correct definition is that 20/20 means that the smallest test chart letters that they can distinguish (threshold) have a stroke width of the letters that subtends 1 arcminute (1/60th degree) of visual angle at the retina. According to the geometric construction of eye charts, the height of the letters are all exactly 5 times the stroke width, so 20/20 can resolve letters that are five arc minutes of visual angle. Everything else is a multiplier on this baseline, so 20/200 can distinguish letters that are 50 arc minutes of visual angle. And 20/70 can distinguish letters that are 17.5 arc minutes of visual angle. If you know the viewing distance and the angle, some basic trigonometry can get you the letter height. It is a measure of distance acuity, so it's pretty perfect for anything 3 m and beyond. Using the same formula for near vision assumes there is no refractive error for close viewing distances, which is a pretty flaky assumption. Critical Print Size is more relevant for near vision tasks, but visual acuity is the global standard measure that everyone refers to, which is unfortunately not particularly helpful for computer screens!

[lauracarlson]

That's fine with me, Bruce. Thanks!

…

On Mon, Jan 24, 2022, 3:30 PM Bruce Bailey ***@***.***> wrote: Just to be pedantic, I don't think we need to define each ratio. But before I make an edit to the glossary <https://www.w3.org/WAI/GL/low-vision-a11y-tf/wiki/Glossary> which is the right term? I don't feel that "Ratio Measurement of Vision" is a good fit. For now, any concerns for making "Visual Acuity" is the indexed term, and folding the CDC paragraph about visual impairment there? OTOH, it might well make sense for 20/70 and 20/200 to be listed terms in the Glossary. If so, are they at the top or bottom? (I.e., how are we alphabetizing numerals?) — Reply to this email directly, view it on GitHub <#133 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABPNHEGJN3APNLSZLRHETF3UXXAHVANCNFSM5GTKLC4A> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[allanj-uaag]

This is an interesting discussion about acuity. I suggest the discussion of distance acuity (20/20, etc) has little bearing on the web-based issues low vision folks are experiencing. Users on the web regardless of device size (save jumbotron or large [>24in] monitors) are using near vision. Near vision acuity is different and measured differently than distance acuity. Distance acuity is measured with the lens at its most relaxed state. When focusing at a near task (16 inches or less) the lens is at its greatest accommodative state. That is the lens is greatly contracted to increase its curvature and allow near objects to be focused on the retina. Alas, the reported measurement is still in terms of 20/20 (which is a confuser). The standard for a reading or near acuity is 16 inches not 20 feet. Jim On Tue, Jan 25, 2022 at 5:38 AM Laura Carlson ***@***.***> wrote:

…

That's fine with me, Bruce. Thanks! On Mon, Jan 24, 2022, 3:30 PM Bruce Bailey ***@***.***> wrote: > Just to be pedantic, I don't think we need to define each ratio. But > before I make an edit to the glossary > <https://www.w3.org/WAI/GL/low-vision-a11y-tf/wiki/Glossary> which is the > right term? I don't feel that "Ratio Measurement of Vision" is a good fit. > > For now, any concerns for making "Visual Acuity" is the indexed term, and > folding the CDC paragraph about visual impairment there? > > OTOH, it might well make sense for 20/70 and 20/200 to be listed terms in > the Glossary. If so, are they at the top or bottom? (I.e., how are we > alphabetizing numerals?) > > — > Reply to this email directly, view it on GitHub > < #133 (reply in thread) >, > or unsubscribe > < https://github.com/notifications/unsubscribe-auth/ABPNHEGJN3APNLSZLRHETF3UXXAHVANCNFSM5GTKLC4A > > . > Triage notifications on the go with GitHub Mobile for iOS > < https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 > > or Android > < https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub >. > > You are receiving this because you were mentioned.Message ID: > ***@***.***> > — Reply to this email directly, view it on GitHub <#133 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABX5ML32QG7DW2XUYFNG3SDUX2DTJANCNFSM5GTKLC4A> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you were mentioned.Message ID: ***@***.***>

-- TSBVI Need assistance? Click this link for help: MOJO HELP DESK <https://tsbvi.mojohelpdesk.com/mytickets/create#/ticket-form-selection> Jim Allan, Accessibility Coordinator Texas School for the Blind and Visually Impaired 1100 W. 45th St., Austin, Texas 78756 voice 512.206.9315 fax: 512.206.9452 http://www.tsbvi.edu/ "We shape our tools and thereafter our tools shape us." McLuhan, 1964

[lauracarlson]

Thanks, Jim. That makes sense. As we no longer are using (20/20, etc) in the proximity doc, it seems like we don't need to define here. Though it can't hurt to update the glossary, if you would still like to, Bruce. Thanks again everyone! Laura

…

On 1/26/22, Jim Allan ***@***.***> wrote: This is an interesting discussion about acuity. I suggest the discussion of distance acuity (20/20, etc) has little bearing on the web-based issues low vision folks are experiencing. Users on the web regardless of device size (save jumbotron or large [>24in] monitors) are using near vision. Near vision acuity is different and measured differently than distance acuity. Distance acuity is measured with the lens at its most relaxed state. When focusing at a near task (16 inches or less) the lens is at its greatest accommodative state. That is the lens is greatly contracted to increase its curvature and allow near objects to be focused on the retina. Alas, the reported measurement is still in terms of 20/20 (which is a confuser). The standard for a reading or near acuity is 16 inches not 20 feet. Jim

-- Laura L. Carlson

[bruce-usab]

I will make some edits to the glossary and reply back to this thread when I am done. Probably COB today soon.