Hi.
I know that a lot of the features in HTML are required for web pages to be accessible to people with poor or no sight, that special browsers can read aloud the text for these.
In order for this to work properly, you must make sure that you follow good HTML coding standards, e.g. you should make sure that your images have an alternate text, that you don't use tables for layout, etc.
But what I'm not sure about is the importance of the fieldset element to group input fields. Do the fieldset tag give any special accessibility benefit, or are they purely used for layout?