**3. Command and feedback**

The goals of HCI can be meet by undertaking engineering process that may result with effective and usable two-way communication between the user and the engineered product. This two-way communication often appears as a command issued by the end user and feedback responded by the product.

The mode of command determines how the user easily issues the instruction to the engineered product while using it. This is further associated with the motor capability of the user as discussed above. For example, in the design of biomechanical systems, as biomechanics focus on the structure and function of the mechanical aspects of biological systems, the motor capability of the user would be vital in the design consideration, among other usability factors discussed above. However, since the interaction is a two-way communication, it is also important to properly design the feedback of the engineered product, in such a way the feedback can be well received and understood by the end user.

Users expect adequate feedback about their actions and ways of easily checking the status [9] of the task they are executing. Feedback has traditionally been seen as a responsive facility to be a communication of immediate system state to the end user [20].

The effectiveness of the feedback from the system is equated to the appropriate selection from tones of interaction styles, where the selection is based on the user, task, and platform model. That means:


Renaud and Cooper [20] classify feedback as archival and immediate. Archival feedback, primarily, is related to information about past activity such as a history of both the user's actions, together with the system's response. It can also be considered "similar to an instruction manual or a system overview that allows users to preview system operations" [21]. Whereas, immediate feedback is used to communicate the present state of the system and involves real-time prompts [21]. In both types of feedbacks presented in [20], the interaction design considers modeling the user so that the user can receive the feedback well, while the assumption is that the user interacts with the system explicitly.

**37**

*Human-Computer/Device Interaction*

computer-to-the-user.

HCI (i-HCI) [6].

*DOI: http://dx.doi.org/10.5772/intechopen.86673*

**4. Explicit versus implicit interaction**

In the customary computing models, users are expected to interact with the system (engineered product) explicitly—hence explicit HCI (e-HCI). In the case of e-HCI, the interaction design aims to design and present the engineer product in such a way users know the presence of the product, and they should learn and understand how to interact with the product. Hence, it is required to design the

However, as the result of smart computing models like ubiquitous computing, where the interaction is desired to be implicit, the notion of the command and feedback design might requires to designing the user-to-the-computer as well so as to enable the computer perceive the context of the user [22]—leading to implicit

Weiser's vision of ubiquitous computing, which demands that computer to be an invisible servant [23, 24], can be realized if the user interacts with the engineered product less obtrusively. This is also pertinent in designing smart devices that

Also, with regard to HCI, invisibility of computers can be achieved, partly through i-HCI [22] and context-aware systems. On the other hand, in addition to providing natural interaction (such as speech and gesture), the e-HCI development for interactive ubiquitous systems requires consideration of capabilities and constraints of heterogeneous platforms and users. Hence, the designers and developers are often compelled to configure and integrate heterogeneous platforms to meet needs of ubiquitous computing, such as mobility and implicit interaction. Therefore, both considerations of designing the-user-to-computer and the

In interactive systems where the user interacts with the engineered product explicitly, the user needs to have the model of the system. Thus, the interaction design focuses on crafting the computer/device, assuming the user will understand the presence of the engineered product, and it can operate it with its motor capability. Thus, the focus is more about the human-to-computer (H2C) interaction.

For example, consider a user who conducts quality inspection in a manufacturing process while the item is being manufactured, the item might need to pass over a conveyor belt. The user (inspector) needs a control over the conveyor—from turning on/off the conveyor to speed control. Thus, the user needs to explicitly access the control panel. In such case, the important usability consideration for the interaction design is positioning the control panel using the right metaphors for the interface. Otherwise, the user would have the knowledge on the existence of the control panel and the associated buttons/switches. Yet the design of the control

Alternatively, the interaction could be computer-to-human. For example (considering the example in the preceding paragraph), instead of requiring the user to directly manipulate the control panel, the conveyor could be designed to be smart and know the absence/presence of the user (inspector) might take actions autonomously or advise the user on favorable actions. This approach makes the interaction implicit. In i-HCI, the presence of the user in the computing model is not primarily to interact with the product. But, the presence can be sensed by the computer, and the computer shall take actions (give feedback to the user) based on previously or dynamically modeled user's context. Implicit interaction is based on the assumption that the engineered product, with which the user interacts, has a certain

understanding of users' behavior and action in a given situations being a user-aware [6]. Thus, the design and architecture of the engineered product need to consider

panel shall consider various usability attributes discussed in Section 2.

improve the efficiency and automation of industrial devices.

computer-to-the-user might be required.

*Computer Architecture in Industrial, Biomechanical and Biomedical Engineering*

environment where the task should be executed.

apply appropriate metaphor selection and application.

issued by the end user and feedback responded by the product.

well received and understood by the end user.

task, and platform model. That means:

the feedback.

interacts with the system explicitly.

consideration of the task environment.

**3. Command and feedback**

in general. For example, performing a task in a destructive environment and silent environment requires different design consideration in building successful HCI. Hence, HCI needs to take into account the context of the task as well as the

Furthermore, a user might be able to accomplish a particular task effectively and efficiently if it knows how to initiate the task, how the task used to be known in one environment (e.g., real-world environment) is represented in the newly developed product (e.g., computer/virtual environment), and how the engineered product gives feedback when the task is completed. In this regard, interaction design shall

The goals of HCI can be meet by undertaking engineering process that may result with effective and usable two-way communication between the user and the engineered product. This two-way communication often appears as a command

The mode of command determines how the user easily issues the instruction to the engineered product while using it. This is further associated with the motor capability of the user as discussed above. For example, in the design of biomechanical systems, as biomechanics focus on the structure and function of the mechanical aspects of biological systems, the motor capability of the user would be vital in the design consideration, among other usability factors discussed above. However, since the interaction is a two-way communication, it is also important to properly design the feedback of the engineered product, in such a way the feedback can be

Users expect adequate feedback about their actions and ways of easily checking the status [9] of the task they are executing. Feedback has traditionally been seen as a responsive facility to be a communication of immediate system state to the end

The effectiveness of the feedback from the system is equated to the appropriate selection from tones of interaction styles, where the selection is based on the user,

• The persona needs to allow the user to receive and understand the feedback.

• The feedback needs to be produced in the context of the task and with the

• The platform (the engineered product) needs to have the capability to produce

Renaud and Cooper [20] classify feedback as archival and immediate. Archival feedback, primarily, is related to information about past activity such as a history of both the user's actions, together with the system's response. It can also be considered "similar to an instruction manual or a system overview that allows users to preview system operations" [21]. Whereas, immediate feedback is used to communicate the present state of the system and involves real-time prompts [21]. In both types of feedbacks presented in [20], the interaction design considers modeling the user so that the user can receive the feedback well, while the assumption is that the user

**36**

user [20].
