Hongzhi Song

A remote usability testing platform for mobile phones

Mobile devices are getting more and more popular in peoples daily life, but their usability becomes a key issue that affects their acceptance by users. Traditional usability testing methods and platforms cannot easily fit into the mobile environment, because the lab settings are not the same as the real environment where they are used. However, the advances in computing power and wireless network bring new opportunities to the usability research. This paper discusses the challenges and presents a new method for testing the usability of mobile phones. This method utilizes the computing power of the so-called “Smart Phone” to record the users activities, such as actions, sound and screen. The recorded data are then transferred via the Wi-Fi network to the observers side in a silent manner without disturbing the user. Experiments were conducted to see whether this method meets the requirement of remote usability testing. The results showed that the data recording could work efficiently without disturbing the user, and the data transfer could be timeliness in an environment with good signal. We believe that this method can be a practical way to study the usability of mobile phones.

Using Project-Based Learning and Collaborative Learning in Software Engineering Talent Cultivation

Higher education is the most important way to cultivating software engineering talents in China, but there is an education gap between the industry and the universities. The current curriculum in university lacked in transferring the experience and skills to students. In this paper, we present how to use project-based learning and collaborative learning in software engineering talent cultivation. We established a learning organization in college of informatics of South China Agricultural University which was named Human Computer Interaction Studio (HCIS). Students can join HCIS on a voluntary basis, and then they can take part in a project team to become a team member. The team accepts a project according to their interest and ability, and then the project manager allocates tasks, formulated work and learning plan. The members of a team would exchange information, discuss some questions and accomplish their tasks together. The study had achieved many good effects in practice, employment and academia. Students can gain expertise, necessary experience and some skills after they used project-based learning and collaborative learning. The results indicated that using project-based learning and collaborative learning can be a good method for software engineering talent cultivation in university.

Image retargeting with multifocus fisheye transformation

Image retargeting is a technique to adapt an original image to diverse screen sizes and aspect ratios on computing devices. This paper focuses on adapting large images for a small display. Some existing methods, such as scaling, cropping, and fisheye warping, are often flawed because they may lose the necessary details of the image, scarify content entirety, or fail to address the content continuity of images with multiple focuses. To address this issue, this paper presents a new fisheye-based approach to retarget images with multiple focuses. With fisheye-based image transformation, this approach can emphasize the focused areas of the image without completely discarding unfocused contents. With a multifocus conflict solution scheme, this approach offers a continuous content transition among multiple focused areas. With image retargeting algorithms implemented with this approach, we conducted experiments to study user preferences of retargeted images under different algorithms. The results of the experiments show that our approach is appropriate for image retargeting.

Fisheye transformation for image retargeting

Image retargeting addresses the problem of adapting images to display on devices with small sizes and different aspect ratios. A fisheye warping method for image retargeting is presented in this paper. Our method emphasizes important aspects of images without completely discarding the remaining parts and can solve the multi-focus problem. We have designed and implemented two fisheye transformation algorithms and three multi-focus conflict solution schemes. The results of usability testing show that our method is appropriate for image retargeting.

A Study on User Experience of Online Games

User experience issues in online games are studied with the theory and method of user-centered design and game playability as the breakthrough point, and then we can get the design guidelines about the user experience. According to the data and then we use factor analysis and correlation analysis to study the degree of correlation between the various indicators and player satisfaction. According to the results, a user experience design guidelines is proposed. This guidelines can be referenced by the designer for the game development and other IT products.

Lenslist: browsing and navigating long linear information structures

List is a simple and useful graphical user interface (GUI) component for organizing linearly structured information when it contains only a few elements. However long lists are difficult to use because only a small part of the list is shown each time, to gain an overview or select elements from a long list the user usually needs to scroll the list many times. This problem becomes more serious as the list gets longer. This paper presents a novel solution, LensList, by applying the focus and context technique to the view of a list. LensList dynamically changes the elements to bigger sizes to form a focal area around the mouse cursor while keeping the elements in the peripheral area in smaller sizes as context. This enables it to display a longer list within the same screen area. Therefore it can be more efficient for performing browsing and navigation tasks.

Cursor caging: enhancing focus targeting in interactive fisheye views

Fisheye view is an effective approach to visualizing and navigating large data sets by offering both local details and global context in the same view. However, by using different magnification factors for detail and context information, fisheye view also leads to new usability issues, one of which is the focus targeting difficulty. This challenge happens when a user tries to select a target to either shift the focus to a new place or chooses the target. Because of the magnification factors applied to the fisheye view, the target moves when the cursor moves, and consequently, the moving distance the cursor actually needs to travel to reach the target does not match the distance between the cursor and target shown on the screen. Task accuracy and efficiency can be affected. This paper analyzes the mechanism of this difficulty and proposes a new technique, cursor caging, as a method to alleviate the focus targeting difficulty in interactive fisheye views. This technique extends the fisheye magnification approach from one element to a focal region, which can contain several elements, and allows the mouse cursor to move freely inside this region without affecting the magnification of objects inside the focal region. In addition to the mathematical representation of this technique, we also develop two designs that incorporate the cursor caging concept in fisheye views, and describe a usability study on the technique. Our results showed that cursor caging can significantly improve the task completion time and reduce the error rate in focusing targeting tasks.

A length compensation method to eliminate the varying length defect in one dimensional fisheye views

Graphical fisheye view is an effective technique for visualizing and navigating large information structures. However, there are still technical difficulties that hinder its broader applications. One of the prominent problems is the varying length effect seen in most fisheye views. The varying length effect refers to a phenomenon that the length (or height) of a fisheye component is not fixed, but it varies with the location of the focal point. This effect may bring some disadvantages that reduce the usability of a fisheye component. To overcome this defect, sporadical solutions have been seen for specific implementations, but a systematic method has not been seen yet. This paper proposes a length compensation method to eliminate the varying length defect for one dimensional fisheye components. The method provides solutions for handling both discrete and continuous magnifications respectively. The mathematical foundation of the method is given, and the implemented prototype proves that it is effective.

A graphical web revisitation tool

Revisiting web pages is common when using web browsers. Commercial browsers provide some revisitation tools for users, for example, back and forward buttons, bookmarks and history lists. However, these tools still have some limitations. In this paper, we presented the design and implementation of a novel thumbnail-based web revisitation tool (TRT). TRT employs enhanced thumbnail and treemaps for improving user experience. Comparing to the other graphical revisitation tools, TRT has three new features. First, TRT display thumbnails and titles in a panel, not a list box. Second, logo-enhanced thumbnails are used as an option by the user. Third, treemaps visualization method is used to change the layout of the panel.

Activescrollbar: a scroll bar with direct scale ratio control

Scroll bar is one of the most frequently used components of graphical user interfaces (GUIs). It is generally considered to provide overview + detail functionality. The scale ratio of a scroll bar refers to the rate of the document dimension to the proportion being displayed. It is usually determined by the length of the document and the height of the display window if considering the case of a vertical scrollbar. The user has no direct control to the scale ratio through the scroll bar, which is inconvenient when dealing with long documents in overview and navigation tasks. This inconvenience is more prominent for small display devices. This paper presents a novel GUI component, ActiveScrollbar, that enhances the standard scroll bar by providing direct scale ratio control without consuming more screen space. This component was expected to be more useful in hand held devices.