ed-informatics.org

Icons and Pedagogic Vectors We all have trouble remembering a program’s graphical icons. The International Standards Organisation (ISO) has a standard for icons – an icon must be interpreted correctly by 2/3 of  test subjects. In usability and error-prevention terms, a 1/3 error rate is poor, but reality is even worse – an experimental study […]

A good principle for medical software is to design for the ED as a worst-case scenario. If it works there, it will work anywhere.No clinicians are as time-pressured as those in a busy Emergency Department. There, distractions – even seemingly minor ones like presenting a complete CBC instead of an abstract – slow the clinician […]

In past articles, we discussed human-illiterate computers, usability, memorability, learnability, Tognazzini’s Paradox, design integrity, simplicity, abstraction, discount usability testing, and personas. Now, we will discuss goals and tasks. These are similar terms, and sometimes used almost interchangeably. But using the terms task and goal sloppily is, according to expert software designers, an error that leads […]

In past articles, we discussed human-illiterate computers, and we discussed usability, memorability, learnability and Tognazzini’s Paradox: how  changing a single word can make big differences in usability. We also discussed design integrity, simplicity, abstraction, and discount usability testing. Now, we’ll talk about personas. It seems to me that personas are a bit like Critical Incident […]

In the first of this series, I tried to persuade you that your computer was human-illiterate, and we defined and discussed usability, memorability, and learnability. In the second, we discussed Tognazzini’s Paradox: how the hardest part of designing an effective program is often what seems the most trivial—sometimes simply a matter of changing a single […]