Similarity confusion
When a user mistakenly initiates the wrong operation because objects with different functions are presented in a like manner.Design flaw in iTunes that produces similarity confusion (see picture below)
Two controls are presented in a like manner:
- Controls are side-by-side.
- Controls are "sliders", operating in the same manner. A user drags the button at the end of the line to the right or the left to change the state of the current podcast.
The controls have very different functions:
- The left-hand control manages volume.
- The right-hand control manages placement within the podcast (beginning, middle, end).
Unintended result
I, several times a month,choose the wrong control and manage to lose my place during a podcast session when my intention is to alter the volume.Solution
The solution is to change the manner in which one of these controls operates. The questions are: which one and how? In this case, screen real-estate issues aside, the nature of the operations helps present suitable answers. When presented with a song or a narrative, we think linearly. A horizontal line - a time line - is a natural way to present something that has a beginning and middle and end. So, the placement control can stay as is. We tend to think of a volume in a different way. We think of louder as more, softer as less. Flipping the volume slider from horizontal to vertical gives us a natural analog of higher=louder and lower=softer, which a stronger correlation than right=louder and left=softer.
A volume control like this one from Microsoft Windows (sorry Apple) would eliminate the similarity confusion created by the current iTunes interface. [Note that this volume control, like many others, uses both height AND width to marry visual volume - overall visual size- with audio volume.]
