When using lists in your content it is essential that they are properly formatted to ensure consistent understanding across operating platforms and assistive devices. Ordered lists (numbered) should be used for related items with a significant sequence whereas unordered lists (bulleted) should be used for related items with no particular order to them.
Lists can help content creators organize information into meaningful groupings and convey sequencing for processes and procedures. Lists can also help users make sense out of large walls of text as well as organize key concepts throughout content. However, when including lists within your content it is essential that lists are properly formatted and used within the proper contexts.
Using proper list structures within your content is essential to ensure that the meaning within lists is not lost when users interact with your content in various ways, such as with assistive technologies or different platforms. Because of this, it is important that lists are properly formatted as lists and not just visually presented as lists. If someone cannot visually interact with your content, then the meaning behind lists can potentially be lost due to improper formatting. When a screen reader user encounters a list, it can announce the presence or the list and tell the user how many items are in the list. However, if a list is not formatted as such then a user might not have the correct context for the information being presented.
Unordered lists, or bulleted lists, should be used for items that are related but have no particular order to them. For example, if I were listing out schools within the Big10 Conference, I would use an unordered list because the items are related but the sequence in the list of items is not meaningful.
If I were to put all Big10 Universities in my list, it could also be beneficial to list them in alphabetical order to help readers.
When choosing a bulleted style to use, it is recommended to use standard bullet points and avoid the use of characters and symbols. It is also recommended to avoid relying on visual cues within a formatted list, such as checkmarks and empty boxes because this information is not always conveyed consistently across assistive technologies.
Ordered lists, or numbered lists, should be used for items that are related and have a specific order to them, such as a sequence or process. For example, if I were listing out schools within the Big10 Conference based on student population, I would use an ordered list because the order is significant to the information being conveyed.
If the sequence (e.g. largest first) of your ordered list is not assumed, then it would be important to include this in the text leading up to the list.
Sometimes it is appropriate to use numbered lists even when sequence is not important. For example, if your text states "10 important list considerations" then, for the convenience of the reader, numbering your list of items will make it easy to see. However, for lists of 5 or less items the use of numbering can be less useful.
A nested list, or a list that occurs within another list, can be used in your content when necessary. To build on the example used previously, if I were listing out schools within the Big10 Conference based on student population and wanted to include the number of men, women, and overall population numbers for each university, I would use a nested list.