As mentioned before, touch is very personal and must occur at the object or person. This is the same with taste, making them similar. In addition, taste has various types which tell the mind and body what is being consumed, and similarly, touch has many types that provide different pieces of information to the brain. The other senses, vision, hearing, and smell, use distance and can provide a sense of spatial relationships and size. Whereas, touch has a limited ability to experience magnitude of space, only able to measure with the count of sensors and movement across a surface. This can be useful when the other senses are limited, but it is not efficient and it requires the user to be in contact with the planes and edges of a space.
One might argue that many or most forms of touch are binary, only having an on and an off. However, with the introduction of multiple touch sensors and multiple types of touch sensors, we develop a sense magnitude as well as directionality. To do this, the touch sensors must be arranged in an array, and the sensors are wired together and coordinated at the brain to provide mapping of an environment. If there are limited touch sensors, the body must probe locations over time and rely on memory to produce a map of a space or object. The sense is so simple in many of its forms that the experience of sensing is only heightened through the lack of use. That is, if something is touched consistently, then there is no reaction and no meaning. However, if there is space or time between activating touch, the experience and meaning are heightened.
With this understanding of limiting the use of touch, it should be the designer’s goal to use the sense strategically and only on occasion. To use it constantly would overwhelm the user and lessen the experience. But, when should someone use the sense? Because it is more effective with limited use, it is best to use touch at specific moments when it is necessary to grab the user’s attention in conjunction with another sense, such as hearing or smell. You find people do this in daily conversation. Someone might touch another’s arm to add gravity or focus to spoken words. The added sense heightens the intensity of an interaction to throw someone into a new understanding or experience.
The worst time to use touch is when trying to show objectivity and to sway someone. Because the sense of touch is very intimate and up front, the use of the sense should be invited and desired by the user. Otherwise, the use of the sense might be inappropriate or even abusive. For things that should be removed from immediate experience, the use of the senses that can be used across space are better. These senses are vision, hearing, and smell, which all can provide experience but they are less invasive and do not intrude on personal space as we interact with the physical environment.
Touch can be a very useful solution for design, because it is used by everyone and the sense experience can vary over time or by the user to create everchanging interactions. Whereas, other senses such as taste and smell can be argued to be limited to a set number of feelings, given by the number of receptors. Even vision and hearing may not vary, especially vision. Hearing allows variation by tone, depending on the source. However, touch can have variation that is private and personal, in that the touch is local and is not shared unless another is at the source of the sense experience. The other senses, besides taste, are shared among the individuals in the space, so they can be said to be public. Touch and taste can be said to be private.
We can use touch in multiple ways. First, we have tactile objects and forms that we touch. However, there is also the opposite where the object or surface touches the user. This is a nice solution for dynamic design, where the touch experience is in movement and addresses the user. A third type of touch is where objects or entities touch one another. This is somewhat foreign, but it allows us to be empathetic and virtually experience the sensation. However, one might argue this is the use of vision. Finally, there is the individual touching another living entity. Again, this is a very personal experience and can only occur with the permission of both parties.