I am current working on a mobile page where there are 2 primary sections. One section has a very few items and each item would have a lots of actions associated with it. The other section has lots of items. I think a horizontal scroll makes sense for the 1st section while a vertical scroll for the 2nd section. However, I am concerned that having 2 different scrolling experience would not be a good user experience. Please comment.
At first glance, this appears to be similar to having a carousel within a browser window. This pattern works well for browsing a series of items. There are in-page indicators of scrolling progress and the UI is arranged in a way that delineates between window-level and component-level scrolling. In other words make sure your target areas are designed to avoid unexpected results.
If possible label or provide other affordances to the user of what to do.
Always test with a few users. And as a rule of thumb, if I think something I've designed is confusing, it probably is.
I have never seen a good mobile web experience any good that had horizontal scrolling. Never. Just don't do it.
If it's an app, you have some more leniency, but it's critically important to be highly cognizant of where you place those horizontal scrolling sections. A good example for a place is for photos that scroll horizontally...it's an actual object that you can sort through while the rest of the content goes vertically.
If you just throw both scrolling mechanisms in, then users will get frustrated because it's too easy, especially on larger smartphones, to scroll slightly diagonally and in a way that wasn't as intended.