The flexibility-usability tradeoff states as flexibility increases, usability decreases, generally to satisfy a higher number of requirements. The concept looks at specialization versus generalization and the affects on usability.
We know it is easier for the user to use an interface with less buttons versus more buttons, simply because the user has less choices. While specificity doesn’t always lead to greater usability, it is part of the premise within this concept that the more specific you are, the easier it is for someone to naturally understand what they are supposed to do and the less chances for the user to experience an error.
Illustrations and narrative as found on (3) Intel’s Developer Zone / Menu Documentation site. The Swiss Army Knife and a series of TV Remote Controls are used to illustrate this example within the Universal Principles of Design.
From the book Universal Principles of Design, “The flexibility-usability tradeoff is related to the well known maxim, jack of all trades, master of none.” For some things this makes a lot of sense as specificity may be too expensive or too inconvenient. The lack of specialization may have to be applied from the users side to allow them to achieve their goal.
I think of how craftsman may use their tools, or how a power user applies software to meet their needs. They do with experience and knowledge, and so flexibility is rewarded but it comes at a cost of time to learn and acclimate to the tool. There are also examples where the approach becomes too flexible, accommodating too many needs at one time. For a consumer device targeted at wide-spread adoption (assumed to be the case for the example below), usability is key. It seems the attempt to integrate a keyboard with a TV for the non-specialized user market is out of reach.
“Sony’s recent… work with Google has resulted in this creation. It is a fine example of how when flexibility is pushed to the limit (in this case a QWERTY keyboard attached to a tv remote control) usability is so diminished that it potentially renders theobject useless. Ergonomically it appears to be uncomfortable, and by looking at the thumbs in the photo not unlike typing into a pocket calculator.” (2)
Within the description above, the object is referred to useless based upon its diminished usability. As you can see in the photo above, there is a lot this device can potentially do based upon its physical interface. You can only imagine the software interface and how Progressive Disclosure may be used to reduce some of the effects of complexity but a device such as this feels like it does and can do too much at once.
Ive thought of a few objects in the real world where the tradeoff between flexibility and usability are apparent and tools and kitchen utensils provided a few good options. An extreme example would the scissors compared to a multi-tool. I’m not sure why I keep this around to be honest, it is hard to use most of the functions without coming into contact with hats edges. In short this is a bottle opener, wire stripper, pliers, knife, scissors, can opener and I am sure I am missing other potential functionality. I don’t use it because it is difficult to use for any of its intended purposes. Part of this issue is with the design of its individual components such as with the handles, in contrast to the scissors which has a more specific grip, which is more comfortable and provides more control when using it, the multi-tool has handles that are able to be used with thick gloves on, but barehanded they are not comfortable and do not allow for a sense of control. The user has to insert their fingers in a way that feels unnatural to hold something.
Other issues come from using specific functionality such as the bottle opener, it is almost impossible not to come in contact with the serrated knife.
(1) Universal Principles of Design – 2010 Lidwell, Holden, Butler
(2) http://userpathways.com/2010/10/usability/ – Thursday, October 14th, 2010
(3) https://software.intel.com/en-us/articles/usability-tradeoff, October 23, 2013 – Diana B.