Forcing users to browse PDF files causes frustration and slow task completion, compared to standard webpages. Use PDF only for documents that users will print. In those cases, following 10 basic guidelines will minimize usability problems.
In testing, we often see users who don't scroll a web page even though there is much useful info below the fold. Often, the reason is "the illusion of completeness" which causes users to believe that they are seeing all there is.
网站上的数据输入表单字段是至关重要的ecommerce and many other applications. Fields need labels and (sometimes) instructions, but placing this text inside the field lowers usability and accessibility and should be avoided.
Useful search suggestions lead to relevant results and are visually distinct from the query text. (This is about how to design the search feature on your own website, whether it's an ecommerce site or not.)
Users often leave Web pages in 10–20 seconds, but pages with a clear value proposition can hold people's attention for much longer. To gain several minutes of user attention, you must clearly communicate your value proposition within 10 seconds.