Well, not really. Like most things a GUI is neither good nor evil, but a shade of something in between. However, for a while, before I caught myself, I was spending large amounts of time writing GUIs for analysis. Time that would have been better spent writing analysis code and debugging it and documenting it and writing papers as a result of it. I taped a piece of paper in front of my desk that said 'NO GUIs' to remind myself. Programming a GUIs is a time trade. Creating a GUI trades time now for time later. The catch is that the time later usually goes to an 'end user' rather than you. When to write a GUI: A GUI for MATLAB or Python is good for code that will be repeatedly used to run analysis by people who have no interest in knowing the underlying code. A GUI is good for tasks that have a strong visual component: this means analysis that is done by displaying data on screen on which you have to indicate things by clicking on them. Your analysis code is all finished ...