Working on a mobile checkout page and would like to know if you'll think its intuitive enough that the user knows there are more products on the right side that could be reached by swiping using the 2 following ways
-showing half of the next item in the cart partially faded to white
-a horizontal scroll bar
are both of these really needed or is one of these enough for the user to get it. if so which one?
Interesting question.
It depends on the maturity of your users.
The scrollbar is good option to give your users a hint about the amount of content that is remaining to be viewed. By the size of the scroller handle. Showing it persistently need not be the case. As the user is interested in the content. This can appear when the user is swiping from left to right. And display scroll bar for the duration it scrolls. And once content stops sliding, it goes off.
The white part on right side is not good indicator that there is some more content. This affodance is also used to display that there is no more content. Remember the contact list, when at the extreme ends of the list, a soft color appears(with elastic animation) indicating no more items to display.
A better solution could be to have an arrow with the white patch and hide the horizontal scrollbar. This will indicate the scrollable area on right.
When the scrolling begins, same arrow with the white patch appears on left too. Indicating the content is available on both the sides.
And during the scroll, you may display the horizontal scroll bar which will send out indications of amount of content left. And the horizontal scroller disappears when scrolling stops.
If I was a user and had that layout in front of me, I would try to swipe using the images first, and if that failed I would try to use the scroll bar to scroll along.
I do, however, consider myself an advanced user of technology.
Having both options will let more advanced users or those who use touch devices primarily use the swipe action, and the scroll bar will allow those who are migrating to a touch device to see that you can scroll as it uses a concept they are familiar with.
If your audience is going to be advanced users only, then the scroll bar might not be needed. If the audience is going to extend to novice users and people who might not be familiar with swipe actions, then use both.
I think the faded item will clearly say "there's more stuff over here", and the way you get to items partially off the screen is, by standard, the swipe. The scrollbar would be useful to show how many items are off-screen (one screenful? a dozen?) and where you are in the horizontal list, but that's clearly a secondary need.
Having both the scrollbar and swiping the images might cause confusion as the swipe directions will be different.
I would say that the partially hidden image to the right is enough of a hint to users.
Scrollbars don't make sense to me in a tactile interface, where you can move the content naturally.
