Mental Models, Input Modes and Cognitive Friction

This entry is part 10 of 12 in the series Medical Computing

If the point of contact between the product and the people becomes a point of friction, then the Industrial Designer has failed. –Henry Dreyfuss, Designing for People, 1955 Mental Models In the first edition of About Face, one of the first design/usability texts (and a great read, much more personal, personable and readable than subsequent, […]

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Icons, Pedagogic Vectors, Forms Design and Posture

This entry is part 9 of 12 in the series Medical Computing

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 […]

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Performance, Data Pixels, Location, and Preattentive Attributes

This entry is part 8 of 12 in the series Medical Computing

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 […]

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Goals vs. Tasks

This entry is part 6 of 12 in the series Medical Computing

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 […]

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Personas

This entry is part 5 of 12 in the series Medical Computing

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 […]

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