3.1 Projects integrated by IOM4TV
The +TV4E platform is a iTV solution conceived to turn its target audience (seniors) into users, and not just passive viewers [34]. The idea is to provide the elderly, access to information related to public and social services. The main goal is to present relevant content to these users while they are watching TV.
+TV4E prevents its users from missing the current TV program by interrupting the broadcast program so he can watch the video suggested by the platform and then return to the point where the TV show stopped. The platform also has a library that stores the recommended videos and uses its recommendation system to suggest this content according to the user’s profile.
The current version of the IOM consists of an eyeglass frame with built-in sensors. IOM uses an accelerometer to capture the movements performed by its users. This data is used as input, then sent over a serial connection and finally converted to cursor movements on the computer screen. Data interpretation is based on an internal communication protocol, necessary for the proper
under-for the proper equipment use.
3.2 IOM4TV Application
IOM4TV is designed to support IOM within the +TV4E platform. In addition to the IOM, the following elements need to be interconnected: a TV set as the primary device responsible for displaying the app content. A set-top-box (STB) decoder that connects to the TV, transforming an external signal into a displayable format. An external computer used to connect to the IOM and convert head movements to cursor movement. In addition to the physical devices, two software components were to enable interaction, as can be observed in the architecture highlighted in Fig. 2.
IOM
COMPUTER SERIAL
COMMUNICATION HTTP
REQUESTS COMMANDS
BY SOCKET
API +TV4E
tv
OK+->>>>1 2 34 5 67 8 90049
TV
tv OK+
->>
>>1 2 34 5 67 8 90 049
Fig. 2. IOM4TV’s architecture.
+TV4E API component act as a Web Service (WS), an intermediate layer of software that receives data from the IOM’s interface, and translates it to commands on the iTV system. The WS receives HTTP (Hypertext Transfer Protocol) POST calls and triggers instructions to be executed over the STB.
The second software component is the interface that interacts directly to IOM.
A specific Graphical User Interface (GUI) was developed to promote the interac-tion between IOM users and the iTV applicainterac-tion. When the click occurs on any
the IOM’s standard operating approach. In this version, the user traverses the interface using the cursor performing continuous head’s movements. When the user stops moving the cursor in a position for a period of time somewhere in the interface, the click action is triggered at the specific position where the cursor is located. This interface has been developed using web tools (HTML, CSS and AJAX). The interfaces evaluated in both testing rounds are highlighted in Fig. 3 (a) and (b).
(a) Web-based v1. (b) Web-based v2. (c) Event-based.
Fig. 3. IOM4TV’s prototype interfaces.
Event-based Prototype The development of the previous interface motivated the development of another kind of interaction. This version detects IOM’s specific motion events to simplify the application usage and reduce discomfort caused by the motion required to traverse the interface. The IOM firmware has been modified to allow its use through motion events. Four movement possi-bilities have been defined: up, down, left, or right. From this firmware change, a second interface was developed using listeners classes that expect predefined events to occur to trigger some functionality. This interface was implemented in Java (Fig. 3(c)).In this prototype, the moving process triggers functionality using the four basic movements. Assuming that the initial focus is on the ”OK”
button, when the user moves his head to the right, focus shifts to the next available button in that direction. This form of movement allows the user to move around the interface. Upon reaching the desired button, performing the upside-down motion triggers the action related to the selected button.
3.3 Evaluation, Results and Discussion
Three different evaluations cycles were executed with the IOM4TV. First, two rounds of user testing were performed on the web-based version, using the
Self-that the best results come with no more than five users running the fewest possible activities [23]. In the first round, the test environment was organized in a University computer lab, with no concerns to reproduce the context in which a user would use IOM4TV. In turn, an occupational therapist guided the second testing round. His main concern was to make the environment attractive, making it look like a traditional TV room, with a comfortable sofa, intimate d´ecor, mood lighting, and pleasant temperature.
Regarding SAM, the Satisfaction aspect reached the highest possible score in both experiments. This positive assessment may be linked to the sense of use-fulness that the elderly felt when participating in the tests. On the other hand, the Excitement dimension obtained opposite results in the two test rounds. Such result indicates the users were very anxious during the first experiment, while they were more relaxed when performing the second test. Thus, the fact that users already know the type of interaction affects this dimension. Finally, the Feeling of Control dimension reached a median score in the first round of testing, revealing usability issues with application interaction. In the second experiment, the results demonstrate the participants were more confident using IOM4TV, re-flecting on the improvement of this item’s evaluation. In turn, Attrakdiff results show that the Pragmatic and Hedonic Quality scores in the first round were 1.91 and 2.19, against the 2.43 and 2.51 ratings in the second series, demonstrating a significant improvement in both aspects measured by the instrument. A second relevant data generated by AttrakDiff highlights the scores given to opposite adjective pairs. Following the Portfolio chart’s trend, the word-pairs analysis results showed improvements in the second round of evaluation. However, the same keyword pairs with lower scores were ranked neutral/negative again. The observations made about the web prototypes, allowed us to perceive problems related to both the application interface and the device’s usage. Specially the need for more explicit visual and audible feedback (when possible). The first round results led to the interface evolution, as can be seen in Fig. 3 (a) and (b). The main changes were related to the simplification of the control interface.
Numeric buttons have been deleted to make the interface as clean as possible.
The fact that there are few open channels available in Portugal led to this deci-sion. In addition, visual feedback has been enhanced to give users more control sensation.
The third test cycle was applied to the event-oriented interface. Its function-alities were initially evaluated only at the development testing level. Thus, two types of evaluation were performed at the application development level: Unit tests on the implemented classes; and IOM4TV functional testing in a devel-opment environment. Despite this, these tests were relevant because, although
As previously highlighted, this work is part of a project that aims to identify recurrent characteristics and needs in different applications in a specific applica-tion domain. Thus, some initiatives have already been developed using IOM as an interaction object in other usage contexts, such as controlled environments [26] or games [7]. In this work, the IOM4TV prototypes’ allowed to collect re-quirements related to the IOM’s usage in the interactive TV scenario. Among the main points raised, we can highlight the following.
Setup features, including essential tasks that should be addressed initially, such as methods for identifying, connecting, and configuring the main function-ality available on the interaction device. It is also necessary to consider the aspects relative to the communication protocol that must exist between the de-vice and applications. Feedback information, such as visual, that was resolved in the application using enhanced interface colors and user-assisted messages. This change was motivated by the need to provide information about the performed functions, such as changing channels or accessing the video library, for example.
Another elicited requirement was the use of an alternative interaction mode (for example, a voice module) to trigger specific events, such as clicks. This request was recurring from users during testing, making it a relevant requirement for future releases.
The operation by events, although still in the development stage, this fea-tures has been presented as a very relevant contribution, since it opens up a range of possibilities for the development of applications that use this behav-ior. Another related point was the development of interaction interfaces using different technologies: one based on Web technologies; and the other use object-oriented programming. This reinforces the understanding that a possible con-ceptual framework should be developed regardless of the technology used in the final implementation. Besides, issues related to simplifying the selection of click-able targets is a requirement to be addressed. Provide methods that simplify the detection of user click intention when utilizing standard device operation.
This issue is addressed most simply when the event mode is used. Allowing the application to be inserted directly into the TV screen is an essential requirement in the context of iTV as it simplifies the use of solutions by eliminating the computer from this usage scenario.
Concerning the development process, it is necessary to strengthen end-user participation by allowing them to cooperate more actively in the assistive so-lution design process. In terms of testing, critical factors such as execution en-vironment, familiarity, and interaction tools directly influence the final result achieved.