About this report

The Bobby report presents an accessibility evaluation grouped by the three priority levels defined by the Web Access Initiative (WAI), as well as browser compatibility and download statistics. As an automated evaluation tool, Bobby is able to detect many accessibility problems and to highlight other possible problems that must be checked. A "Bobby" hat in the original page (if displayed) indicates that Bobby was able to detect a Priority 1 problem with accessibility. A question mark indicates a Priority 1 item that needs to be checked by the user. Follow the links provided in the report to get details about any problem reported, including how to repair it, if needed. For more information on the report, please access our online documentation.

To be Bobby Approved, a page must pass all of the Priority 1 accessibility checkpoints established by the WAI.




Click on the error messages below to find out more information.

Priority 1 Accessibility

This page does not meet the requirements for Bobby Approved status. Below is a list of 1 Priority 1 accessibility errors found:

  1. Provide alternative text for all images. (7 instances)
    Lines 111-114, Lines 156-159, Lines 197-200, Lines 217-220, Lines 246-249, Lines 277-280, Lines 315-318

User Checks

User checks are triggered by something specific on the page; however, you need to determine whether they apply. Bobby Approval requires that none of them apply to your page. Please review these 7 item(s):

  1. Provide alternative content for each SCRIPT that conveys important information or functionality.

  2. If an image conveys important information beyond what is its alternative text, provide an extended description. (25 instances)
    Lines 40-41, Lines 42-44, Lines 45-46, Lines 47-49, Lines 50-51, Lines 52-53, Lines 54-55, Lines 56-57, Lines 58-59, Lines 60-61, Lines 62-63, Lines 64-65, Lines 66-67, Lines 72-73, Lines 74-75, Lines 76-77, Lines 81-82, Lines 111-114, Lines 156-159, Lines 197-200, Lines 217-220, Lines 246-249, Lines 277-280, Lines 315-318, Line 370
  3. For tables not used for layout (for example, a spreadsheet), identify headers for the table rows and columns. (3 instances)
    Line 38, Line 101, Line 347
  4. If you use color to convey information, make sure the information is also represented another way.

  5. Provide both a description and a synchronized caption for video information. (2 instances)
    Lines 155-156, Lines 166-167
  6. If a table has two or more rows or columns that serve as headers, use structural markup to identify their hierarchy and relationship. (6 instances)
    Line 70, Line 38, Lines 90-92, Line 88, Line 101, Line 347
  7. Provide a synchronized textual transcript for the audio in videos. (2 instances)
    Lines 155-156, Lines 166-167

The following 4 item(s) are not triggered by any specific feature on your page, but are still important for accessibility and are required for Bobby Approved status.

  1. Ensure that descriptions of dynamic content are updated with changes in content.

  2. Use the simplest and most straightforward language that is possible.

  3. Avoid ASCII art.

  4. If you can't make a page accessible, construct an alternate accessible version.

Not Bobby ApprovedThis page does not yet meet the requirements for Bobby Approved status.


Priority 2 Accessibility

Bobby Approved status is assigned on the basis of Priority 1 items in the Web Content Guidelines. For a higher level of accessibility you may also want to examine Priority 2 and Priority 3 items. 3 Priority 2 issue(s) that Bobby has identified are presented below.

  1. Avoid use of deprecated language features if possible. (56 instances)
    Line 37, Line 86, Line 94, Line 104, Line 110, Line 118, Line 123, Line 134, Line 139, Line 145, Line 155, Line 165, Line 171, Line 174, Line 189, Line 196, Line 205, Line 216, Line 223, Line 227, Line 230, Line 233, Line 246, Line 252, Line 264, Line 269, Line 276, Line 283, Line 287, Line 291, Line 296, Line 307, Line 313, Line 314, Line 322, Line 323, Line 332, Line 333, Line 336, Line 346, Line 354, Line 364, Line 365
  2. Use relative sizing and positioning (% values) rather than absolute (pixels). (5 instances)
    Line 38, Line 88, Line 101, Line 104, Line 347
  3. Make sure event handlers do not require use of a mouse. (6 instances)
    Line 42, Line 47, Line 52, Line 56, Line 60, Line 64

User Checks

7 Priority 2 issue(s) that Bobby has identified are presented below:

  1. Mark up quotations with the Q and BLOCKQUOTE elements.

  2. Check that the foreground and background colors contrast sufficiently with each other.

  3. Use header elements in the proper sequence and not for bold text.

  4. Avoid using movement in images where possible. (24 instances)
    Lines 40-41, Lines 42-44, Lines 45-46, Lines 47-49, Lines 50-51, Lines 52-53, Lines 54-55, Lines 56-57, Lines 58-59, Lines 60-61, Lines 62-63, Lines 64-65, Lines 66-67, Lines 72-73, Lines 74-75, Lines 76-77, Lines 111-114, Lines 156-159, Lines 197-200, Lines 217-220, Lines 246-249, Lines 277-280, Lines 315-318, Line 370
  5. If scripts create pop-up windows or change the active window, ensure that the user is aware this is happening. (1 instance)
    Line 10
  6. Avoid using tables to format text documents in columns unless the table can be linearized. (6 instances)
    Line 70, Line 38, Lines 90-92, Line 88, Line 101, Line 347
  7. Add a descriptive title to links when needed.

The following 8 item(s) are not triggered by any specific feature on your page, but are still important for accessibility.

  1. Use a clear, consistent navigation structure.

  2. Make sure your document validates to formal published grammars.

  3. Where it's possible to mark up content (for example mathematical equations) instead of using images, use a markup language (such as MathML).

  4. Use metadata to add computer-understandable information about the page.

  5. Group related elements when possible.

  6. Ensure that dynamic content is accessible or provide an alternate presentation or page.

  7. Offer a site map or table of contents, and provide a description of the general layout of the site, the access features used, and how to use them.

  8. Use the latest technology specification available whenever possible.


Priority 3 Accessibility

Bobby Approved status is assigned on the basis of Priority 1 items in the Web Content Guidelines. For a higher level of accessibility you may also want to examine Priority 2 and Priority 3 items. 2 Priority 3 issue(s) that Bobby has identified are presented below.

  1. Identify the language of the text. (1 instance)
    Line 1
  2. Provide a summary and caption for tables. (6 instances)
    Line 70, Line 38, Lines 90-92, Line 88, Line 101, Line 347

User Checks

5 Priority 3 issue(s) that Bobby has identified are presented below:

  1. Provide abbreviations for long row or column labels. (6 instances)
    Line 70, Line 38, Lines 90-92, Line 88, Line 101, Line 347
  2. Specify a logical tab order among form controls, links and objects.

  3. Consider adding keyboard shortcuts to frequently used links.

  4. Group related links.

  5. Provided a linear text alternative for tables that lay out content in parallel, word-wrapped columns. (6 instances)
    Line 38, Line 70, Line 88, Lines 90-92, Line 101, Line 347

The following 9 item(s) are not triggered by any specific feature on your page, but are still important for accessibility.

  1. Create a consistent style of presentation between pages.

  2. Provide a link at the beginning of a group of related links to bypass the group.

  3. Use icons or graphics (with accessible alternatives) to facilitate comprehension of the page.

  4. Allow users to customize their experience of the web page.

  5. Use the ABBR and ACRONYM elements to denote and expand abbreviations and acronyms.

  6. Offer navigation bars for easy access to the navigation structure.

  7. Place distinguishing information at the beginning of headings, paragraphs, lists, etc.

  8. If ASCII art is present, provide a means to skip over it.

  9. Offer different types of searches for different skill levels and preferences.


Browser Compatibility Errors

The following section contains a list of 15 browser compatibility errors. Browser compatibility errors help to determine when HTML tags and their attributes are not compatible with certain web browsers or HTML specifications. Browser compatibility errors do not affect the accessibility rating of a page.
  1. Unknown attribute NATURALSIZEFLAG in element IMG. for browser(s): Lynx2.7, Explorer4.01, Navigator4.0, HTML4.0 (7 instances)
    Lines 111-114, Lines 156-159, Lines 197-200, Lines 217-220, Lines 246-249, Lines 277-280, Lines 315-318
  2. Unknown attribute ALIGH in element DIV. for browser(s): Lynx2.7, Explorer4.01, Navigator4.0, HTML4.0 (3 instances)
    Line 37, Line 86, Line 133
  3. Attribute ALINK in element BODY needs a valid color. for browser(s): Explorer4.01, Navigator4.0 (1 instance)
    Line 7
  4. Unknown attribute BORDERCOLOR in element TABLE. for browser(s): Lynx2.7, Navigator4.0, HTML4.0 (1 instance)
    Lines 90-92
  5. Unknown attribute NAME in element IMG. for browser(s): Lynx2.7 (7 instances)
    Lines 42-44, Lines 47-49, Lines 52-53, Lines 56-57, Lines 60-61, Lines 64-65, Lines 74-75
  6. Unknown attribute WIDTH in element TD. for browser(s): Lynx2.7 (1 instance)
    Line 364
  7. Attribute NOSHADE in element HR is assigned an incorrect value. for browser(s): Lynx2.7 (2 instances)
    Line 350, Line 360
  8. Attribute SIZE in element FONT must be assigned an integer. for browser(s): Explorer4.01 (3 instances)
    Line 171, Line 230, Line 287
  9. Unknown attribute BGCOLOR in element TABLE. for browser(s): Lynx2.7 (2 instances)
    Line 88, Lines 90-92
  10. Required attribute TYPE is missing from tag SCRIPT for browser(s): HTML4.0 (1 instance)
    Line 10
  11. Unknown attribute BORDERCOLORLIGHT in element TABLE. for browser(s): Lynx2.7, Navigator4.0, HTML4.0 (1 instance)
    Lines 90-92
  12. Unknown attribute BORDERCOLORDARK in element TABLE. for browser(s): Lynx2.7, Navigator4.0, HTML4.0 (1 instance)
    Lines 90-92
  13. Unknown attribute COLS in element TABLE. for browser(s): HTML4.0 (1 instance)
    Lines 90-92
  14. Unknown attribute BGCOLOR in element TD. for browser(s): Lynx2.7 (1 instance)
    Line 94
  15. Required attribute ALT is missing from tag IMG for browser(s): HTML4.0 (7 instances)
    Lines 111-114, Lines 156-159, Lines 197-200, Lines 217-220, Lines 246-249, Lines 277-280, Lines 315-318

Download Time

The following three-column table gives download time statistics for the images, applets, and objects on this page. The first column contains the URL of each item, the second column the item size in kilobytes, and the third column the approximate download time for each item when using a 28,800 baud modem. At the end of the report, an arbitrary delay of 0.5 seconds is added for each file to account for slow-downs caused by HTTP connection times.

URL
Size
Time (secs)
http://thunder.nsstc.nasa.gov/bookshelf/news/nasa_space_based_lightning_detectors.html 20.42 K 5.67
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_left.gif 0.36 K 0.10
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_home.gif 0.44 K 0.12
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_middle2.gif 0.38 K 0.10
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_primer.gif 0.44 K 0.12
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_dataset.gif 0.64 K 0.18
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_research.gif 0.96 K 0.27
http://thunder.nsstc.nasa.gov/images/tabs/listab_back_validation.gif 0.57 K 0.16
http://thunder.nsstc.nasa.gov/images/tabs/listab_front_middle1.gif 0.38 K 0.11
http://thunder.nsstc.nasa.gov/images/tabs/listab_front_bookshelf.gif 0.65 K 0.18
http://thunder.nsstc.nasa.gov/images/tabs/listab_front_right.gif 0.38 K 0.10
http://thunder.nsstc.nasa.gov/images/desc/desc_spacer_left.gif 0.16 K 0.04
http://thunder.nsstc.nasa.gov/images/desc/desc_spacer_middle.gif 0.18 K 0.05
http://thunder.nsstc.nasa.gov/images/desc/desc_spacer_right.gif 0.16 K 0.04
http://thunder.nsstc.nasa.gov/images/titles/titles_bookshelf.jpg 12.03 K 3.34
http://thunder.nsstc.nasa.gov/bookshelf/images/ldarr.tnl.gif 14.02 K 3.89
http://thunder.nsstc.nasa.gov/bookshelf/images/storm2.gif 22.21 K 6.17
http://thunder.nsstc.nasa.gov/bookshelf/images/graph.tnl.gif 5.93 K 1.65
http://thunder.nsstc.nasa.gov/bookshelf/images/feb22_23.tnl.gif 19.46 K 5.41
http://thunder.nsstc.nasa.gov/bookshelf/images/nl1c.tnl.gif 15.17 K 4.21
http://thunder.nsstc.nasa.gov/bookshelf/images/mar20_21.tnl.gif 13.96 K 3.88
http://thunder.nsstc.nasa.gov/bookshelf/images/mar19_20.tnl.gif 25.37 K 7.05
http://thunder.nsstc.nasa.gov/images/fullwhite.gif 3.34 K 0.93
Total
157.61 K
43.78
HTTP Request Delays
--
11.50
Total + Delays
--
55.28