The studies we analyzed have evaluated interaction on touchscreen devices with different touchscreen technologies, screen sizes, resolutions, touchscreen technologies, orientations and positions (i.e., horizontal, vertical, fixed, handheld). Tactile interactive systems should be designed to be used on different situations and fit different screen sizes.
Only two of the studies analyzed compared the interaction between two screen sizes (smartphone and tablet) (Harada et al., 2013; Kobayashi et al., 2011). The study by Kobayashi et al. (2011) demonstrated that older adults’ interaction on tablet outperformed the smaller screen size despite the longer traveling distances for executing the gestures of interaction (Kobayashi et al., 2011). In another study, Harada et al. (2013) also report older adults took longer times on tablet than on smartphone for dialing numbers, scrolling contact lists and looking for a location on a map (Harada et al., 2013). Further studies should investigate the causes of the different performances in these two devices in order to improve interaction for older adults, particularly on small screen sizes.
Tasks II.3.1.3
In this section we describe the training tasks (practice trials, familiarization tasks) and evaluation tasks executed during the HCI studies for assessing tactile interaction performances and testing usability of interactive systems.
All the studies analyzed allowed subjects to conduct practice trials before the experiment started. Longer familiarization periods where proposed for users without previous experience with touchscreen devices (more practice trials or even one week period). The training tasks employed are detailed in the Table II.6.
Table II.6 HCI studies: Training tasks in the studies analyzed
Kind of training Number of studies and details
Familiarization period One study asked participants to practice the execution of gestures of interaction on the interactive system designed for the experiment at least once a day (Kobayashi et al., 2011).
Demonstration One study evaluated the effects of animated tutorials, presented before participants executed the tasks, on the execution of the correct gestures of interaction (Leitao and Silva, 2013). In another study, experimenters debriefed the participants after the experiment demonstrating some techniques for improve the accuracy of the interaction (Harada et al., 2013).
Printed tutorial One study presented a printed tutorial before the participants executed the task (Apted et al., 2006).
Practice trials Ten studies allowed participants to execute some trials with the interactive system used for the experiment and discarded the data from these practice trials.
(M. K. Chung et al., 2010; Hourcade and Berkel, 2006; Hwangbo et al., 2013; Jin et al., 2007; Leonard et al., 2005; Lepicard and Vigouroux, 2012, 2010a, 2010b; Nicolau and Jorge, 2012; Tsai and Lee, 2009)
Tutorials and training can be used to help older adults to improve their performances and positively influence their attitudes towards touchscreens (Leitao and Silva, 2013). Familiar user interfaces and simple tasks are helpful to start activities with novice users (Hwangbo et al., 2013). A week experience improved users’ performances especially for dragging and pinching gestures (Kobayashi et al., 2011).
The studies we reviewed including novice and experienced users of touchscreen devices confirms that tactile interaction seems easy to use for older adults (Harada et al., 2013; Kobayashi et al., 2011; Nischelwitzer et al., 2007; Piper et al., 2010). Concerning the progress of interaction performances during the experiment, Mertens and Jochems (2010) report that older adults showed better performances and stabilization after the 20th trial for selecting targets with tapping tasks on touchscreen (Mertens and Jochems, 2010).
Subjects worked on groups during some studies (Apted et al., 2006; Gonçalves et al., 2011; Harada et al., 2013), which was helpful to generate more natural situations during the experiment. Working in pairs can be useful for older users because they can learn by observing their partners (Apted et al., 2006; Gonçalves et al., 2011; Harada et al., 2013).
The tasks executed during the evaluation procedure, assessing touch information for analysis, were elementary or complex. The elementary tasks were executed on interactive systems presenting a simple layout (few or no distractors) and users should do one single task at the time. Complex tasks, on the other hand, were consisted of several sub-tasks and represent more realistic situations (e.g., creating a postcard (Apted et al., 2006), reading and sending emails (Holzinger et al., 2007), medical applications (Nischelwitzer et al., 2007)). Elementary and complex tasks executed during the experiments of the studies we analyzed are described in Table II.7 and Table II.8 respectively and discussed on the sequence.
Examples of elementary tasks are: reading, selecting targets, typing (text, digit or passwords) or executing patterns of gestures on the touchscreen. Some studies evaluated different elementary tasks, as described in the Table II.7.
Table II.7 HCI studies: Elementary tasks in the studies analyzed
Elementary tasks Number of studies
References
Reading 3 studies (Hollinworth, 2009; Nischelwitzer et al., 2007;
Piper et al., 2010)
Target selection 10 studies (Findlater et al., 2013; Hourcade and Berkel, 2006;
Hwangbo et al., 2013; Jin et al., 2007; Lepicard and Vigouroux, 2012, 2010a; Moffatt and McGrenere, 2007; Nicole Schneider et al., 2008; Vetter et al., 2011; Wood et al., 2005)
Text or digit input 11 studies (M. K. Chung et al., 2010; Harada et al., 2013;
Hollinworth, 2009; Kobayashi et al., 2011; Lee et al., 2012; Nicolau and Jorge, 2012; Nischelwitzer et al., 2007; Piper et al., 2010; Tsai and Lee, 2009;
Umemuro, 2004; Wright et al., 2000)
Patterns of gestures 9 studies (Findlater et al., 2013; Harada et al., 2013;
Kobayashi et al., 2011; Leitao and Silva, 2013;
Lepicard and Vigouroux, 2012; Mertens and Jochems, 2010; Stößel, 2009; Stößel et al., 2010;
Wacharamanotham, 2011)
Only three studies evaluated reading tasks with older users. Reading tasks consist of evaluation of text fonts and comfort aspects, but also the interaction technique for scrolling, passing through pages and resizing the text. While reading, participants appreciate when they can adjust font size (Hollinworth, 2009). However, older adults prefer graphical elements with clear functions, such as soft buttons for increasing the size of the text, instead of multi-touch gestures (i.e., pinching) (Hollinworth, 2009). Authors recommended limiting the number of lines of text (Nischelwitzer et al., 2007) and avoid scrolling because certain users can loss orientation between lines (Apted et al., 2006), in this case, they suggest arrow’ buttons to help users to navigate linearly going forward or backward analogously to book metaphor.
Target selection tasks and typing are affected by target’ sizes, spacing and location, on small touchscreen devices (Hwangbo et al., 2013) and also on larger screen sizes (Lepicard and Vigouroux, 2010a). Results of the experiments show that it is better to reduce the number of targets and the number of interactions to facilitate the use of touchscreen for older adults (Hourcade and Berkel, 2006; Jin et al., 2007; Lepicard and Vigouroux, 2010a). Four or six targets are easier to identify and to interact than eight, especially for users older than 70 years old (Lepicard and Vigouroux, 2010b). Concerning the targets’ locations on small screen devices, hand movements from top to bottom are easier to visually impaired older users according to Leonard et al. (2006) (Leonard et al., 2005). Hwangbo et al. (2013) reported that diagonal movements are slower to execute, so designers should consider positioning the targets to facilitate bottom-to-top, top-to-bottom or side-to-side movements (Hwangbo et al., 2013).
Concerning the graphical interfaces displayed on touchscreen, familiarity is an important aspect for interaction (Apted et al., 2006; Hollinworth, 2009; Piper et al., 2010).
Digit input is easier for older adults with explicit displays, such as numeric keypads instead of cursors or sliders (Nischelwitzer et al., 2007). Sliders can be used only to present few positions for selection (e.g., markers setting intervals), otherwise selecting a specific position requires highly accurate movements. For soft keyboards and numeric keypads, familiar arrangements (e.g., placing the key zero above the eight) and labeling (e.g., space bars, erase buttons) can help users to find the functionalities they need and prevent mistakes (e.g., sending an email instead of erasing a character) (M. K. Chung et al., 2010; Harada et al., 2013; Nischelwitzer et al., 2007).
The familiarity with the gestures of interaction is also helpful to older users (Stößel, 2009). When using patterns of interaction gestures with one finger on single touch devices, it is recommended to avoid complex patterns (Stößel et al., 2010).
The execution of complex tasks, composed of multiple elementary tasks, allows the analysis of interaction as a whole on more realistic situations. The kinds of complex exercises analyzed on the reviewed studies are detailed on Table II.8.
Table II.8 HCI studies: Complex tasks in the studies analyzed
Complex exercises Number of studies References
Use a digital agenda 1 study (Iglesias et al., 2009)
Email 2 studies (Hollinworth, 2009; Umemuro, 2004)
Phone tasks 2 studies (Gonçalves and Ueyama, 2012;
Harada et al., 2013) Photo manipulation 1 study (Apted et al., 2006)
Health care systems 2 studies (Nischelwitzer et al., 2007; Piper et al., 2010)
Map visualization 1 study (Harada et al., 2013)