In this first article about the usability of everyday products I want to talk about the experience with my mp3 player. I used it often while cycling or walking to work. It is an interesting example because the design limitations are not visible while using the design in, e.g., a shop before it is bought. I noticed the limitations only after using it for a while.
The mp3 player is designed as a USB stick. Songs can be put on via connecting it to the computer. The most important function of an mp3 player is the selection of songs and to adjust the volume. For both of those interactions this device offers a joystick like button. Moving the joystick to the right/left selects the next/previous song and moving it up and down adjusts the volume. Those joystick movements reflect a logical design pattern.
Another important function of an mp3 is to deliver music on the go. I use to carry the device in the pocket of my jacket or trouser while cycling. This, however, shows a limitation of the design. The joystick extends slightly over the shape of the mp3 player which often led to an unwanted interaction jumping to the next or previous song.
Another limitation is the interaction required to switch the device on or off. The user is required to press and hold down a small silver button for 3-4 seconds. The button is placed on the bottom of the mp3 player. The interaction might not sound difficult, but if the button is pressed the music immediately stops playing. This can lead to the wrong interpretation that the mp3 player is switched off. However, to switch the mp3 player off the user is required to hold the button pressed down for 3-4 seconds. The display shows a bar marking the shut-down process. While cycling I do not use the display and miss this information. In general, from a non-technical perspective, it is not clear why the designer chose such a long process to switch the device off.