smart objects that become less agreeable than they can be,
for a purpose

I. Examples

• Resistive lighting system.
  Assume that a smart home is able to evaluate, on a day-by-day basis, the behavior of its occupants when it comes to energy conservation. The daily grades are averaged over a moving time window to produce a longer-term energy waste factor. The factor takes on a value in the set {1, 2, 3, 4, 5}, with a lower number corresponding to less energy waste. Now, to switch on any light in the home, the user has to press the respective (push-button) light switch as many times as the current value of the energy waste factor (i.e., from one to five). Switching a light off always requires the user to press the button just once.
• Resistive TV remote control.
  The remote introduces a delay between pressing a remote’s button and the respective reaction (e.g., a change of the channel). The delay varies from zero to, say, the maximum of 3 seconds. It is driven by the weather outside: the nicer the weather at the moment (i.e., the more pleasant it is outdoors), the larger the delay. The delay may affect either all buttons or just the channel up/down buttons, to target zapping.
• Resistive phone.
  When the user starts to make a phone call in certain contexts, the phone’s LED blinks to convey that the call might be a bad idea. Specifically, the user activity is detected as one of three possibilities: “default,” “on the train,” and “driving a car.” In the default state, there is no blinking. On the train, the diode blinks with medium frequency to indicate that the prospective call may disturb fellow passengers. In the car, the diode blinks with high frequency to warn that talking on the phone while driving is dangerous.

II. Basic concepts

A resistive object is one that in response to some contextual conditions becomes noticeably less “agreeable” to the user. This may happen in one of three ways (modalities of resistance):

1. First, the object’s performance may become lower than what the object is capable of (as in the resistive TV remote).
2. Second, the object’s usability may drop (as in the resistive lighting system).
3. Third, the object may be delivering some negative, “disapproving” stimuli to the user (as in the resistive phone). In that case we talk about explicit resistance.

The loss of agreeability is context-dependent and occurs to a varying degree, as the context changes. We refer to the degree, to which the object has become less agreeable, in any of the ways just mentioned, as its resistance level (a value from the interval [0, 1]). At the resistance level equal to zero (no resistance), the performance and usability are at their best, and there is no explicit resistance. At the level equal to one (maximum resistance), depending on the modality, the performance or usability may be at their lowest, or explicit resistance stimuli may be most intense.

A key design principle: even at the highest resistance level, i.e., when an object has become least agreeable, it remains fully functional and usable. For example, the performance may noticeably drop, but it remains acceptable. What matters is that the user can easily detect performance variations.

We envision resistivity as a technique from the toolbox of persuasive technologies. Specifically, resistance is meant to dissuade the user from (or make her more careful about) some undesirable, object-specific resisted behavior.

As to the relative timing of the resisted behavior and resistance, one can identify three basic modes:

1. Resistance as a payback. An object may become more resistant in return for the user’s past behavior. When the behavior improves, the resistance goes down. This mode is exemplified by the resistive lighting system.
2. Resistance as immediate feedback. The resistance is meant to encourage the user to change her behavior at the moment. The more “incompatible” the present behavior is with the current context, the higher the resistance. This is exemplified by the weather-driven resistive TV remote.
3. Resistance as advance feedback. The operations on the object, which in the current context reflect worse choices (less rational, less efficient, more wasteful, etc.), may offer more resistance than those reflecting better choices. As the user handles the object, she is offered an instant, discouraging evaluation of a “bad” action that she is likely to take in the immediate future. This is exemplified by the resistive phone.

III. User's conceptual model

Excerpts from user manuals, which explain resistivity for three different objects, might read as follows. Note that the user conceptual model is based on qualitative, approximate statements.

• With your resistive lighting system, the number of times you need to press a button to switch on the lights depends on how well you’ve been conserving energy in your home lately. That can be any number from one to five. The fewer, the better. If pressing a button once does the job, congratulations – you’ve been very conscientious about saving energy. If you need to press a button five times, you’ve been quite negligent; please consider being more careful to improve your score (and save both money and the environment).

• Your resistive TV remote gently reminds you that sometimes it may be a better idea to enjoy outdoors rather than to watch TV. Specifically, when the weather in your area is inviting, you will experience slight delays when zapping through channels. The more perfect the weather outside, the longer the delay (there is no delay when the weather is nasty). At “worst,” the change to a new channel will occur three seconds after you press the button. If the delay gets close to that, you should really consider taking a walk in the sunshine.

• Your resistive phone makes you aware that in some situations it may be dangerous or considered impolite to make a call. That is indicated by your phone’s LED blinking when you are about to call. The more frequently the LED blinks, the more inappropriate it is to proceed. The medium blinking frequency indicates not being considerate, e.g., disturbing your fellow passengers on the bus or train. The high frequency indicates danger, e.g., an increased likelihood of causing a car accident. In case of blinking, please consider making the call later.

IV. Personal vs. community-wide resistive objects

So far, the resistive objects presented in our examples are used by an individual or family. One might call them personal. Now consider the following example.

• Resistive escalator.
  Imagine an escalator and regular stairs next to it. The system maintains an escalator usage factor, equal to the fraction of people choosing the escalator over stairs. The higher the escalator usage factor, the slower the escalator. However, even at the lowest speed the escalator remains fully functional; this is perfectly feasible, given the range of escalator speeds considered normal. (Of course, the resistive escalator is not suitable if people need to be continuously transported in great numbers.)

In the above example, the object is used by a possibly large group of people. We call such objects community-wide. The modalities and modes of resistance identified for personal resistive objects do apply to community-wide ones.

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See our paper:

• Domaszewicz, J.; Gluhak, A.
  Resistive Objects
  8th International Conference on Human System Interaction HSI’2015, pp. 122-128, 25-27 June 2015, Warsaw, Poland, doi:10.1109/HSI.2015.7170654
  pdf(presentation), IEEE Xplore