I think the difficulty you’re going to find here is that UI and UX are such fluid titles that any practical difference between the job titles has become moot for most companies. Many hiring managers don’t understand the difference between UI and UX, and as such associated job titles and responsibilities have become very, very muddied. Either might do some or all of the work of the other, depending on where you’re employed and the wants/needs of your employer.
Furthermore, if an employer hires both separate UI and UX professionals, the chances are very, very high that they will be working intimately and seamlessly together. This only serves to further muddy the waters.
So how do we go about separating the differences between the two positions? A solid list of UI should do A and UX should B really isn’t possible from a practical standpoint, especially without knowing a lot more about the employer’s situation and needs.
I’m sorry if that’s not very helpful for your particular set of needs. From a real-world perspective, unfortunately it’s the reality.
In theory, however, I think we can speak generally about what should be done by UX professionals, what should be done by UI professionals. To do this, however, we really need to understand that UX professionals are primarily involved with solving problems, while UI professionals are primarily involved in the next step of implementing the solution. In no particular order, some duties that follow these guidelines are as follows:
- User Research
- Competitive Research
- Interaction Design
- Use Case Definition
- Persona Creation
- Journey Mapping
- Lo-fi mockups, Wireframing & Iterative Design
- User Testing
- Business Intelligence Analysis
- Visual design
- High-fi mockups
- Adjusting Layouts to Fit Development Stacks
- Creating User Guides
- Content Creation
I’m sure many will disagree with where some of these pieces belong, but hopefully this will help move the conversation along a bit.