User interface design and user experience engineering are used interchangeably web app design world and that’s both incorrect and misleading. So what is the big difference?
User experience engineering (UX) is the big strategic thinking that you wrap around your entire web product or business. User interface design (UI) is what you create from those big strategic ideas to visually steward your customers through their daily interactions with the web application.
If you have the luxury of starting a project from scratch then you would start with the UX before you considered the UI. The design of the product is then based on the UX you have decided to create. Think of web application design metaphorically like building a new family house. Before the architect starts to draw up the plans you have to decide on the user (home owner) experience. You need to make decisions on how the building will support and enhance your lifestyle. How will the house accommodate your kids and their activities? How will the house design deal with the changing seasons and the changing requirements as your family gets older? Each of these ideas will determine the dimensions, layout and aesthetics of the house.
Not defining the UX fist can result in the design becoming the informer of the user experience. Going back to our home metaphor, imagine for a moment that the designer or architect of the house didn’t know you had kids or assumed you preferred traditional styles to contemporary styles? The final house design would disappoint you and the experience of living there would be less than optimal.
When you are looking for a web app designer for an application it’s essential that the designer or design team knows these subtle differences and are proficient in user interface design. The must make sure they understand the UX before you start to design the web application or product. Ideally they should also have deep knowledge of Agile and/or LEAN development practices so they can build an application interface that be used as the platform for the development team.