Insights for the TV Interface from the Mobile Phone Interface

Journal of Usability Studies, Volume 4, Issue 4, May 2009, pp. 166-177

Article Contents

Needs Analysis

The following sections discuss user analysis, task analysis, and system analysis.

User Analysis

TV content (programming) is usually targeted for more than one person. The user’s age is very important for TV programming in relation to age-based ratings that describe the level of sexual or violent content. Also, there are programs tailored or targeted for specific user groups such as single women, business men, or children. Meanwhile, TV manufacturers design and produce the devices based on the assumption that various types of users and more than one user can watch the TV at the same time. Thus, the user interface of TV is not designed for specific user groups.

For mobile phones, some services are designed for specific user groups and some are designed for every user group, although the main services related to voice interaction are designed for all users. Unlike TV, mobile phone manufacturers design the user interface according to the user profile they are targeting. Thus, the user interface included by the device manufacturer is personalized to some extent. Table 2 compares characteristics of TV and mobile phone users.

**Table 2.** User Characteristic Comparison between TV and Mobile Phones
	User characteristic	TV	Mobile phone
Manufacturer	Target user	All ages	All ages or specific ages
	Personalization	Group	Individual
	Usage environment	Stationary	Mobile
	Usage/operation distance	3 m	Handheld
Programming/ service provider	Target user	All ages or specific ages	All ages or specific ages
	Personalization	Group	Individual
	Usage environment	Stationary	Mobile
	Usage/operation distance	3 m	Handheld

Task Analysis

The most important task for TV is watching televised programs. Thus, other peripheral services or on-screen display menus should not interfere with the task of watching a program. The main task of mobile phones is having voice conversation. Users should be able to talk on the phone no matter what other peripheral tasks are being performed. The TV can let users do multi-tasking of the main task by providing multiple pictures on one screen. Multi-tasking for mobile phones, for example, is to let users watch video or listen to music while talking on the phone.

Because the number of functions implemented in electronic products is increasing and the convergence of various products is being accelerated, structuring tasks is getting more complicated. Structuring tasks can be done in various ways based on certain criteria, but one example is shown in Table 3. This method of structuring tasks classifies tasks into installation, use of basic functions, use of applications, setup, and maintenance based on the life cycle of the product. This method can be easily applied to any other electronic product.

**Table 3.** Task Analysis of TV and Mobile Phones
Task	TV	Mobile phone
Installation	Connect antenna Connect wires Connect power lines Install battery for remote Mount on the wall	Subscribe to service provider Update phonebook Install battery
Basic functions	Turn on/off Navigate channels Volume control and mute External input control Watch TV	Turn on/off Send/receive voice calls Send/receive video calls Send/receive text messages View calling history Update phonebook
Applications	Reserve program Previous channel Favorite channels Multi-language sound Caption Caller ID EPG DVR PPV	Taking and view pictures Download and listen to music Watch video Email Internet browsing Download and playing game
Setup	Screen setup Sound setup Channel setup Time setup	Screen setup Sound setup Lock the phone Application setup
Maintenance	Clean up Move	Recharge battery Exchange battery Clean up

System Analysis

The display resolution of digital TV is significantly greater than that of analog TV. Digital TV uses one of two formats: 1280 × 720 pixels in progressive scan mode (abbreviated 720p) or 1920 × 1080 pixels in interlace mode (1080i), and each utilizes a 16:9 aspect ratio. For the digital terrestrial television, there are digital TV sets with built-in digital tuners, while the digital TV sets without built-in digital tuners need a separate tuner to receive terrestrial digital television broadcasts. For digital cable and satellite television, special set-top boxes are required for receiving digital television broadcasts (Figure 1). In this case, users have two separate remote controls for the TV and the set-top box.

The display resolution of mobile phone screens has increased to the level of QVGA (320 x 240) and VGA (640 x 480). Also, the CPU capability of mobile phones has become powerful enough to provide multi-tasking with a camera, MP3s, mobile TV, and games. One significant difference between a mobile phone and TV comes from the size of the screen. The small screen-size of mobile phones presents a major limitation in their usability. Menus and applications on a mobile phone must compensate for the small size of the screen (Ahmadi & Kong, 2008; Burigat, Chittaro, & Gabrielli, 2008), whereas TV has enough space to present complex menus and applications. However, TV must also use space carefully so that the main task of watching programs is not compromised.

Figure 1. Illustration of TV system with user