Evaluating User Experience in Games: Concepts and Methods - Lirmm
Evaluating User Experience in Games: Concepts and Methods - Lirmm
Evaluating User Experience in Games: Concepts and Methods - Lirmm
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11 <strong>Evaluat<strong>in</strong>g</strong> Exertion <strong>Games</strong> 201<br />
11.5.1 Physiological Measurements<br />
So far, we have highlighted how our work suggests that movement <strong>and</strong> engagement<br />
can be <strong>in</strong>tertw<strong>in</strong>ed <strong>in</strong> exertion games. However, captur<strong>in</strong>g objective movement<br />
might only tell one story: different people exert themselves differently when perform<strong>in</strong>g<br />
the same physical movement, depend<strong>in</strong>g on their fitness level <strong>and</strong> bodily<br />
capabilities. Physiological measurements could create a more objective measure<br />
as to how much exertion players <strong>in</strong>vested <strong>in</strong>to the game, possibly contribut<strong>in</strong>g<br />
to a more complete underst<strong>and</strong><strong>in</strong>g of engagement <strong>and</strong> user experience. One costeffective<br />
way of measur<strong>in</strong>g a participant’s exertion <strong>in</strong>tensity is to use a heart rate<br />
monitor. Heart rate monitors are widely available, <strong>and</strong> a few models allow <strong>in</strong>terfac<strong>in</strong>g<br />
with a PC for subsequent analysis. Athletes <strong>and</strong> hobby sports people often<br />
use heart rate monitors <strong>in</strong> their tra<strong>in</strong><strong>in</strong>g, hence study subjects can often already be<br />
familiar with such devices, <strong>and</strong> knowledge about their advantages <strong>and</strong> shortcom<strong>in</strong>gs<br />
is widely available. Human–computer <strong>in</strong>teraction research has previously used<br />
heart rate monitors not only for measur<strong>in</strong>g, but also for controll<strong>in</strong>g games (Nenonen<br />
et al. 2007, M<strong>and</strong>ryk et al. 2006), further<strong>in</strong>g acceptance <strong>in</strong> the community through<br />
its pervasive use. Heart rate monitors are also small, lightweight <strong>and</strong> battery powered,<br />
mak<strong>in</strong>g them suitable for mobile use (Mueller et al. 2007). They can provide<br />
physiological user data for little cost <strong>and</strong> are easy to adm<strong>in</strong>ister; however, the type<br />
of exertion activity that is <strong>in</strong>volved dur<strong>in</strong>g the game play can determ<strong>in</strong>e its utility,<br />
as heart rate monitors are best utilised <strong>in</strong> aerobic activities. It should also be noted<br />
that a player’s heart rate can be affected by other factors outside the game environment,<br />
too. Hart gives a few examples: Outside temperature, too much cloth<strong>in</strong>g or<br />
caffe<strong>in</strong>e dr<strong>in</strong>k<strong>in</strong>g can affect heart rate data (Hart 2003). If such data are not useable,<br />
researchers have suggested to use performance measurements to evaluate exertion<br />
activities, for example, through measurement devices <strong>in</strong> the participants’ shoes or<br />
by us<strong>in</strong>g GPS data to track a player’s movements (Mueller et al. 2007). We believe<br />
these approaches can, if supplemented with body data from the user, give <strong>in</strong>sights<br />
<strong>in</strong>to the energy expenditure dur<strong>in</strong>g game play, contribut<strong>in</strong>g to a wider picture of<br />
game experience.<br />
11.5.2 Borg’s Perceived Exertion Scale<br />
Another way of measur<strong>in</strong>g a participant’s exertion level is by us<strong>in</strong>g Borg’s scale<br />
(1998), which aims to acquire the rate of perceived physical exertion by the participant.<br />
It is a simple scale, requir<strong>in</strong>g no technical equipment, which was designed for<br />
athletes <strong>and</strong> sports coaches to be used to assess the <strong>in</strong>tensity of tra<strong>in</strong><strong>in</strong>g <strong>and</strong> competition.<br />
The Borg scale, or often referred to as “Rat<strong>in</strong>g of Perceived Exertion”, is<br />
presented to the participant <strong>in</strong> form of a chart. The participant then has to select how<br />
hard she/he feels, she/he is work<strong>in</strong>g by giv<strong>in</strong>g a rat<strong>in</strong>g such as “Light” or “Maximal”.<br />
The orig<strong>in</strong>al scale has 21 po<strong>in</strong>ts of exertion, but variations with less po<strong>in</strong>ts exist<br />
(Hart 2003). The Borg scale has the advantage that it is easy to adm<strong>in</strong>ister <strong>and</strong><br />
underst<strong>and</strong> by participants. It has also been demonstrated that the scale correlates