Good user interface designs :
1> Windows Aero feature of Windows Vista :
Purpose of the overall interface : To provide a dynamic, realistic interface to the user.
Particular aspect I find good: It provides translucent screens to the user. Because of this, user can view not just the foreground screen but can also get an idea of things happening in the background screens. Morever, it also provides a 3D flip view by which user can view objects in a 3 dimensional view. This provides a realistic effect.
Why it's good : It's good because it improves on the look and feel of the system and also provides user with a good surfing experience.
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Purpose of the overall interface : To provide a high speed interface to the user and help him provide an efficient interface for the jQuery tutorial.
Particular aspect I find good: In this site AJAX - Asynchronous Java script and XML is used. Because of this, when the user clicks on any button, the entire screen is not refreshed, just the required part of it is.
Why it's good : As there is no page submit, the time taken to perform user operation is less and it provides a good and fast interface to the user.
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Bad user interface designs :
1> login screen and Forgot password screen of a web portal of Lex Vehicle Leasing : This is a web portal of Lex Vehicle Leasing on which I had worked.
Purpose of the overall interface : To provide user with an option to allow him to reset his password.
Particular aspect I find bad: On the login screen there is a link Forgot password. When user clicks on it, he is taken to the Forgot password screen where he inputs his username by which his password gets reset and he then comes back to the Login screen. However, there is no link on Reset password screen to take him back to the Login screen. The browser Back button is also disabled for security reasons.
Why it's bad : if a user by mistake clicks on Forgot password link, he has to reset his password at any cost without which he cannot go ahead.
Why it might have been designed that way : It was designed that way because it is a company's policy that no screen should have a link to the login screen other than logout link. However, there was no logout link on Forgot password screen, since, on this screen the user has not yet logged in.
Suggest a better design if possible : What I would do is I would keep the browser Back button enabled until those screens where user logs in. Since, on Forgot password screen, the user has not yet logged in, the Back button would be enabled and he can use it to go back to Login screen if desired.
Image2> Yahoo beta :
Purpose of the overall interface : To provide a more efficient and dynamic interface to the user as compared to other mail clients.
Particular aspect I find bad: The interface is divided into many tabs.There are some major tabs like - Inbox, Drafts, Sent items etc. A user cannot view all these tabs at the same time. He can view either Inbox or Drafts or Sent items. He can view n number of tabs related to individual mails.
Why it's bad : If the user wants to view Sent and Draft items at the same time, he cant.
Why it might have been designed that way : The reason it might have been designed this way is that Drafts, Sent, Inbox all access the server, so if they all would have been allowed to be opened at the same time, there would have been multiple request response sessions required.
Suggest a better design if possible : One way would be to allow opening of multiple such tabs and in that case not making dynamic refreshing of page. So the interface would be a bit slow when multiple such tabs are opened but it will allow user to operate on multiple such tabs.