The first striking feature of the Lasko Oscillating Desktop Fan is numbered dial that affects the fan’s speed. From left to right, the numbers read 1, 2, 3, and 0. Zero indicates the off position which is not entirely clear, but because of the lack of an off function the user can infer that zero does indeed turn the machine off. The lowest function, 1, is counterintuitively placed on the opposite side of the off mark. This presents a disadvantage if the use
r wants to use to lowest setting, as they must twist through each of the other functions before reaching 1. Conversely, this is a convenient affordance if the user plans on using the highest setting.
Once the fan speed is set, the user can choose if the fan will oscillate or not. The mechanism to start or stop oscillation is not very clearly marked, but is a standard function that appears across many fans. If the user has experience with other fans, they will easily be able to determine that the push/pull mechanism on the top of the fan indicates not oscillating/oscillating. If the user is inexperienced, they will probably have more trouble sorting out this feature.
Additionally, the head of the fan can be tilted up or down. This capability is poorly presented, as there is no obvious knob or button that allows the tilting motion. The user may eventually pull or push to hard on the fan and find that it tilts. Tilting is a useful affordance, but could have been presented more obviously to the user.
The user will surely know when the fan is on/off. They will feel the airflow, see the blades oscillating, and hear the motor. As the fan speed increases, the airflow increases, the blades turn more rapidly, and the noise grows louder.