The user needs to skim through stories without scrolling or any other unnecessary mouse movements.
A slideshow shows several stories with images, one at a time. After a specific set time interval one story is replaced by another – often with an animated transition.
Transitions between images are most often a sliding effect although a simple fade is also a popular choice. The most important design choice when it comes to transitions is to make it seem natural. Animations should never be used for showing off; only to support the usability and understandability of UI.
Use numbers, bullets, squares, or thumbnails to represent all the images in the slideshow. These provide a way of letting the user have a sense of where he or she is in the slideshow and help set expectations as to how many stories are left and available.
Use numbers if it’s important to let the user now exactly how many stories a slideshow has. Use bullets if it doesn’t matter, and thumbnails if you want to inspire the user to jump past the sequential order of stories that you’ve chosen beforehand.
Slideshows steal attention! Especially if they are combined with animated transitions. Put slideshows together with blinking advertisement and other bright, animated or otherwise attention-stealing elements on the page and you have mayhem. If more than one element screams for attention, the user will get lost. If you have multiple elements that scream for attention other than the slideshow, the slideshow will only help diffuse users’ attention instead of focusing it.
Consider whether your slideshow is going to represent the main and most important stories of your site – if it doesn’t, then leave out the slideshow. A slideshow directs attention towards itself. Don’t overdo it.
Increase the effectiveness of your slideshow by adding buttons for each story that calls out for attention. Buttons help users know what to click. However, be careful not to fall in the common trap of just labeling your button with “Read more”, unless that is really the only action the user can do by clicking on that button. Texts like “Support”, “Donate”, “Buy”, and “Watch video” are much more effective in getting users to click and set expectations of what they will get.
Common navigation elements include:
In order not to present the user with too many options at first, consider hiding navigational elements (such as “previous” and “next” buttons) until users hover the slideshow image. Too many options at first can confuse users and make them go away before they even got started. Reveal their options as their interest is sparked.
Slideshows seem to go one of two ways:
Slideshows highlight several different stories on the same screen real estate. They allow users to quickly skim through stories without scrolling, moving the mouse or in any other way use navigation options. Users at the same time save attention as they don’t have to concentrate on navigation but at the same time calls for attention every time the slideshow switches to a new image. Slideshows focus users’ attention sharply on the content instead of interacting with the browser.
1 Slideshows In Web Design: When And How To Use Them by Matt Cronin at smashingmagazine.com