Things that are useful for improving a listing with a search engine have nothing to do with improving a listing in a directory. The only exception is that a good site, with good content, might be more likely to get reviewed than a poor site. Because they are automated and index so many sites, search engines may often find information not listed in directories. To the flip side, they may also pull up unrelated information for the topics you're searching for. Search engines, such as HotBot, create their listings automatically.
Search engines crawl the web, then people search through what they have found.
If you change your web pages, search engines eventually find these changes, and that can affect how you are listed. Page titles, body copy and other elements all play a role. Some search engines maintain an associated directory. Being included in a search engine's directory is usually a combination of luck and quality. Reviewers often keep an eye on sites submitted to announcement places, then choose to add those that look appealing.