> Working with my aging mother, modern UIs are very complicated. I am a software developer with over 20 years of professional experience designing and building

> Working with my aging mother, modern UIs are very complicated. I am a software developer with over 20 years of professional experience designing and building systems. I recently got the COVID vaccine. While I was in the observation area, there was a screen projected advising me to set up my 2nd dose using my smartphone while I waited. I searched for the clinic web site where I first signed up for the vaccine, and then I filled in the same form again that I used to get a my first appointment. One of the options was "Have you already had your first dose?" I checked that, and my expectation was that the system would determine that I have priority for setting the next appointment. Instead the system kicked me into a waitlist. Fortunately, as I was leaving, the staff were adamant about asking whether I had my second appointment set up. I explained that I used the website for setting up appointments and that I was on a waitlist. They were confused and said I should have been immediately scheduled for my second appointment. Fortunately there were a couple of staffed stations set up where they could set up your second appointment if you had trouble doing it via your smartphone. The staff member told me I had gone to the wrong website (??) and, in a slightly annoyed demeanor, asked me for my email address. They did whatever they do on their end, and I got a date and time set up. I think it's perfectly reasonable to go to the website you initially used to set up your first appointment in order to set up your second appointment, and I'd expect the system to give you priority in getting your second appointment when you check the box indicating that you've already had your first dose. (Otherwise, why even bother asking??) I guess the thing I was supposed to do was search my email inbox for one of three messages where there was an embedded link I was supposed to click on. But this wasn't discoverable, and none of the information on the screen told me that was what I was supposed to do. If an experienced software developer misuses the automated system, I'm not sure how the general public doesn't run into problems using it. Of course I do have a knack for always wedging myself into the corners of almost any system I use, perhaps because I don't think like your typical member of the general public does when it comes to systems.