Usability Design
Ayush Saran - K0845801
CIM 506 - Usability Engineering
Words: 3348
Abstract:
The objective of this Usability design is to apply user-feedback, published research and design guidelines to building a successful user-centred iPhone application.
GetFed is a location-aware user-centric food recommendation application for the iPhone and iPod touch platforms; it uses GPS positioning to fetch recommendations from nearby restaurants based on user-submitted reviews stored online on a database.
This paper presents iterative designs and paper prototypes based on user feedback, along with design rationale for the choice of design elements and screen layout. The paper will also present a future plan for further evaluation study along usability engineering techniques for analysis and evaluation.
1. Introduction and Background
1.1 Current Trends in Location Aware Applications
Current trends in mobile phones and applications predict that in the near future, advances in computing environments will free users from the constraints of traditional desktops, allowing them to take their ubiquitous computing with them on the move. [2]
Yang Li (2004) believes that one especially promising branch of this ubiquitous computing experience is location-enhanced computing, services and applications [1]. This field has started seeing mass commercialization, due to the fact that high-end models from cell-phone manufacturers, such as Apple's iPhone and Nokia's N95 have begun to integrate location-sensing devices like GPS sensors. [3]
Some examples of location aware applications and services are:
AT&T's Find Friends service, which finds the current location of a friend [4]
Tenereillo's Trapster, which alerts drivers to the location of police speed traps nearby [5]
Moop.me's iNap, built for commuters it determines where they are, and wakes them up when they are close to their destination, allowing them to catch some shut-eye [6]
1.2 GetFed
The latest applications for mobile environments can take advantage of contextual information, such as a users current location, to offer greater services to the user. Knowledge of the user's current location, as well as tracking previous locations, can be used to provide the kind of services that a real tour guide would offer. [2]
GetFed builds on this idea to offer users real-time reviews of nearby food, based on the restaurants lying in the users immediate periphery, as determined by GPS positioning. The reviews themselves are user-submitted; but use a default database from other review websites like Yelp when user-submitted reviews are unavailable for that particular area or restaurant.
GetFed places greater emphasis on individual dishes, rather than restaurants, allowing users to see what specific items are recommended as good to eat, by other users, for that location.
2. Analysis
2.1 Target Audience
GetFed is aimed primarily at iPhone users, and also to its sister product the iPod Touch which uses the same platform as the iPhone. This platform was chosen because of its large market share and affluent user group.
About half of iPhone users are under age 30 and about 15% are students [9], making them more likely to be early-adopters for technologies like location-aware applications. In a recent survey by Rubicon, 40% of the iPhone users surveyed said strongly that they want to add new software applications to their iPhones. [9]
The latest sales figures from leading market research firm NPD Group, show Apple's iPhone 3G gaining market share rapidly, accounting for 17 per cent of the market, second only to Motorola's RazR2 [7]. The iPhone is now outselling the BlackBerry Curve, BlackBerry Pearl and Palm Centro, making it the number one Smartphone in the US. [8]
1. Users
The application is aimed at owners of Apple's iPhone and iPod Touch devices, living primarily in large metros and major cities across North America, Europe and some parts of Asia.
2. Context of use
The primary context of use imagined for this application is for users to quickly locate restaurants near their current location. Another secondary context is to find new food items and interesting dishes from restaurants they already know.
3. Tasks
At the prototype level, the two major tasks envisioned are:
Find nearby restaurants
View Recommendations
4. Software
The application will be built upon the iPhone OS version 2.2.x released by Apple in the iPhone SDK. Like Mac OS X, from which it was derived, the iPhone's OS uses the Darwin foundation [12]. Central to the development of this application is 'Core Location', a software framework in Mac OS X. It is primarily used by applications on the iPhone OS 2.x for detection of the device's location.
5. Hardware
The only supported hardware for this application will be Apple's iPhone and iPod Touch, both of which run an ARM-based processor, and use OpenGL rendering for graphics, powered by the PowerVR 3D graphics hardware accelerator [13].
2.2 Usability requirements
Different usability attributes are usually weighted differently according to the task being performed. With location-aware applications, such as GetFed, relevance and satisfaction are probably the most important criteria. While these attributes could be seen as somewhat subjective to the user's experience, approximate target levels can be set and measured nonetheless.
The table below lists possible metrics for defining and evaluating the applications usability.
| Requirement | Metric |
|---|---|
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Relevance |
Were users able to find real recommendations within their immediate area |
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Satisfaction |
Were users happy with the quantity of search results and quality of recommendations |
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Efficiency |
Were users satisfied with the time taken to perform certain tasks |
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Learnability |
Over periods of use were users able to reduce the time taken to reach certain stages |
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Participation |
Did users participate in submitting their own recommendations, or reviewing and rating other users recommendations |
2.3 Task and Object Models
The list below includes the most general tasks being performed by the system, and thus identifies objects involved in the execution of these tasks.
| Task | Objects |
|---|---|
|
Find nearby restaurants |
User (Current Position), Locality (Immediate Area), Restaurants |
|
View Recommendations |
Restaurants, Food Items (Recommendations and Ratings), Reviews, Other Users |
3. Design
3.1 Prototype
This prototype represents version 1 of the GetFed application design and is meant only to illustrate the application screens and task-flow process. It is not a working iPhone application.
The following screens demonstrate the process of 'finding a nearby restaurant'.
3.2 Description of interaction with prototype
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1. Opening ApplicationOn opening the application from the iPhone's 'Home Screen' the user is presented with a splash screen that introduces them to the GetFed application, and informs them that they are currently being located. The application located the users based on 3 primary location tactics. GPS Positioning from the inbuilt GPS Sensor Wi-Fi based location for hotspots with known geo-position Cell-tower triangulation as a last resort tactic |
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2. Select RestaurantsOnce the user has been located, the application retrieves a list of nearby restaurants for that location. The user is then presented with a list of nearby restaurants; sorted by distance from the user's current location. The restaurants are presented along with the cuisine they represent. |
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3. Restaurant MenuAfter selecting their restaurant of choice the user is presented with a menu of popular dishes for that restaurant. This list is sorted in descending order, with the most recommended dishes appearing at the top. The items are rated and submitted by other users of the GetFed application. If there is a lack of user-submitted items from the GetFed database then generic content is leased from other applications such as 'Yelp' and similar services. |
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4. Individual ItemOnce the user has selected an individual item to view, the interfaces changes from the list/table view and enters the item view. In this interface the users can see the 'most helpful' review for the item (as voted by other users), average rating and number of votes for that particular item/dish. The interface also displays a user-submitted image of the dish/item. In absence of a user-submitted image, a generic image is displayed from a database of stock images of food, searchable by dish/item title. |
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5. Chrome-less ViewSimilar to the iPhone's Photos.app, the GetFed application allows users to tap the screen to get rid of the interface and leave behind only the image of the dish/item. This view is useful to see details of the image and allow users to zoom in/out of larger resolution images. |
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6. ScrollThe application also allows users to scroll through the recommended menu items in the iPhone's trademark horizontal scroll method, which is also used by the inbuilt Photos.app etc Once the user has located a dish/item of interest, they can tap the screen again to bring back the interface overlay for that particular dish. |
3.2 Design Rationale
In the design of this application good use has been made of the iPhones touch and direct manipulation capabilities. Metaphors are also used throughout the interface, because the use of metaphors in design elements helps novice users quickly grasp how the application works [14].
1. Opening Screen
The opening screen provides the first immediate feedback when users launch the GetFed application. Locating users can be a lengthy operation, especially when the primary methods of location detection fail and alternatives modes have to be used. The opening screen serves as a status reports in case the location positioning turns into a lengthy operation. This is in line with Apple's Human Interface Guidelines for the iPhone, which state that during operations that last more than a few seconds, applications should show elapsing progress and explanatory messages. [14]
2. Item Display
Whenever possible lists of items and choices are displayed as a list. Apple's Human Interface Guidelines for the iPhone recommend presenting choices or options in list form, so users can easily scan them and make a choice. [14]
3. Item Selection
Whenever items (such as restaurants or dishes) are selected, the entire line is highlighted and kept visible so that users know that they have directly manipulated the item via touch.
This is in line with Apple's Human Interface Guidelines for the iPhone which recommend enhancing the sense of direct manipulation in iPhone applications by allowing tangible objects on the screen to remain visible while the user performs actions on them, so that the result of the user's action are immediately apparent. The benefits of following these guidelines of direct manipulation are that users more readily understand the results of their actions when they can directly manipulate the objects involved. [14]
4. Item Sorting
Item sorting for items/dishes is shown by placing their 'star' rating alongside the item/dish. This allows users to immediately identify the pattern of decreasing stars, which they co-relate with lower ratings, making the descending nature of the ratings apparent.
5. Breadcrumbs
It is recommended that whenever possible, the use standard controls and behaviours, that users are already familiar with should be preferred over arbitrary navigation. [14]
Keeping in line with this guideline the GetFed application uses Breadcrumbs to aid backwards navigation when viewing individual items/dishes.
6. Overlays
The review overlays on individual items/dishes provide quick access to relevant information about the individual item/dish while not completely blocking view of the underlying image. This is vital because an opaque overlay would not allow users to view images of the item/dish, which are assumed to be important attention grabbers while browsing.
3.3 Shortcomings
1. Aim
To detect possible shortcomings and oversights in the design of the GetFed iPhone application.
2. Method
A survey was carried out amongst 20 iPhone and iPod Touch users, asking them to click through a paper-prototype of the GetFed application. They were asked to navigate to http://www.ayushsaran.com/dev/iphoneapp/ and while observing the interlinking screen-shots, make notes of any possible annoyances they encounter and suggest improvements.
3. Results
The survey respondents provided a few edge-case scenarios and suggested some improvements that the current interface doesn't address, such as:
1. Manually entering the location - In case the application was unable to automatically locate the user, or the user was located inaccurately, or the user wants to see options around an area they aren't currently in, for example around their office, or in a city they want to visit.
2. Augmenting Search Results - In case the results were insufficient or unsatisfactory.
3. Sorting options - To toggle the sorting of restaurants by distance, cuisine, recommendations or alphabetically.
4. Nutritional Information - on food items, when available.
4. Design iterations
4.1 Prototype (v2)
In consideration of the user feedback received, a second version of the prototype was designed to work out known issues with application usability and user satisfaction.
4.2 Brief Description of Design Iterations
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1. Launch ScreenIn accordance with Apple's Human Interface Guidelines for the iPhone [14], The Launch screen was updated to show a progress bar, which acts as an activity indicator during the location process, which could turn out to be lengthy. According to the guidelines, Operations that last more than a few seconds should show elapsing progress and display explanatory messages. This is because in addition to seeing results of their actions, users expect immediate feedback from apps. [14] |
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2. Select RestaurantThis screen was redesigned to integrate a button, which allows users to manually update their location. Participants requested this feature during the initial user-feedback session. An option to 'Load more restaurants' was also added for edge cases where the results were insufficient or unsatisfactory. |
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3. Change Location ScreenThis screen was added to allow users to manually update their location. In accordance with Apple's Human Interface Guidelines for the iPhone [14], The interface relies minimally on text-input, reducing the chances of errors or frustration by self-suggesting from a live updating list of destinations based on the users initial text input via the Keyboard Modal View. |
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4. Restaurant MenuThe only change to this screen was the addition of the county flag to the Application title bar. This helps signify the nationality of the cuisine through visual cues, building on the information from the previous menu. |
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5. Individual Item Overview ScreensA Tap bar was added to this screen to break additional information into easy to reach tabs. According to Apple's Human Interface Guidelines for the iPhone [14], the tap bar is ideal when the application provides different perspectives on the same set of data, or different subtasks related to the overall function of the application, Such as viewing Nutritional Information or Reviews on the same dish/item. The Nutrition and Reviews screens use variants of the iPhones default 'Table View' Interface to display their data, while a grid layout is preferred for the Gallery section to make scanning of the thumbnails easier. |
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5. Evaluation Plan
5.1 Aims and Expected outcomes
The aim of this evaluation plan is to detect possible shortcomings and oversights in the GetFed iPhone application. During the evaluation process, we expect to gain insight into how people interact with the iPhone platform, specifically in regards to location-aware applications.
The study aims to gain clarity over mismatches between user expectations, from the application and the platform, and real word results.
5.2 Method
1. Participants
Participants for the study will be sourced from existing iPhone and iPod Touch owners; these will be volunteers and will not be compensated financially for their effort. They may be provided with a gratis copy of the application upon public launch.
In keeping with the mass-market target audience of the iPhone and GetFed, restrictions will not be placed on participant age, technological prowess or financial standing.
2. Data Gathering Technique(s)
Participants will be monitored through the use of a two-camera setup that records the participant's interaction with iPhone's screen as well as another camera pointed to capture the users facial expressions. Participants will also be observed through a one-way mirror by researchers who will provide guidance and monitor the time taken by users to complete tasks.
In addition to empirical data, qualitative data will also be collected. Participants will be asked to speak aloud through their session and answer questionnaires after the evaluation session.
3. Tasks
In order to fully evaluate the applications features and interface participants will be asked to perform the following tasks:
Run the application, and find nearby restaurants.
Manually change their location to 'London, U.K.'
Sort the list of nearby restaurants to show only 'Italian' Restaurants
Vote for the highest recommended item/dish at a restaurant of their choice
Add a review and photo of dish/item to a fictional restaurant supplied by the study.
4. Procedure
Users will be briefed with the application, its scope and its features. They will run through the pre-defined tasks one by one in a linear manner, any task they skip or are unable to complete is taken as having failed. This is a reflection on the complexity of the task not the capability of the user, because it is the application and not the user, which is being tested.
Observers will record the time taken to complete tasks to gain empirical data about the efficiency of the application interface. The users facial expressions and speech are recorded to gain insights into task satisfaction.
Once all the tests have been performed and data has been collected and analyzed, any tasks that appear to need redesign will be re-assessed and fixed for the next set of user testing.
6. References
[1] Li, Y., Hong, J. and Landay, J. (2004) Topiary: A Tool for Prototyping Location-Enhanced Applications, ACM CHI Letters, Vol. 6, No. 2.
[2] Abowd, G. et all (1997) Cyberguide: a mobile context-aware tour guide, Wireless Networks, v.3 n.5, pp 421-433.
[3] 3MobileShop - GPS Mobile Phones [Online] Available at http://www.3mobileshop.co.uk/gps-phones.asp [Accessed 2nd Jan 2009]
[4] AT&T Find Friends [Online] Available at http://www.attwireless.com/mmode/features/findit/FindFriends/ [Accessed 21st Dec 2008]
[5] Trapster [Online] Available at http://www.trapster.com/ [Accessed 26th Dec 2008]
[6] iNap [Online] Available at http://www.moop.me/inap.php [Accessed 29th Dec 2008]
[7] Thomson, I. (2008) Apple iPhone gains market share - Second most popular handset in the US [Online] Available at http://www.vnunet.com/vnunet/news/2227601/apple-iphone-gains-market-share [Accessed 21st Dec 2008]
[8] NPD Group Inc. (2008) iPhone 3G Leads U.S. Consumer Mobile Phone Purchases in the Third Quarter of 2008 [Online] Available at http://www.npd.com/press/releases/press_081110.html [Accessed 25th Dec 2008]
[9] Rubicon consulting (2008) Whitepaper: The Apple iPhone - Successes and Challenges for the Mobile Industry - A study of iPhone users [Online] Available at http://rubiconconsulting.com/insight/whitepapers/2008/04/the-apple-iphone-is-easily.html [Accessed 28th Dec 2008]
[10] Wired Inc. (2008) Wired.com's iPhone 3G survey data [Online] Available at []http://blog.wired.com/gadgets/2008/08/global-iphone-3.html [Accessed 23rd Dec 2008]
[11] Bomsdorf, B., and Szwillus, G. (2003) Task-Object Models for the Development of Interactive Web Sites, Human-computer Interaction: Theory and Practice, [n.p.] Lawrence Erlbaum Associates, pp 248-252.
[12] Benson G. (2008) iPhone SDK - Overview (the SDK, not the Event) [Online] Available at http://nessence.wordpress.com/2008/03/07/iphone-sdk-overview/ [Accessed 9th Jan 2009]
[13] Apple Inc. iPhone Dev Centre [Online] Available at http://developer.apple.com/iphone/index.action [Accessed at 8th Jan 2009]
[14] Apple Inc. iPhone Human Interface Guidelines [Online] Available at http://developer.apple.com/iphone/library/documentation/UserExperience/Conceptual/MobileHIG/ [Accessed 5th Jan 2009]
[15] Create with Context (2008) How people really use the iPhone [Online] Available at http://www.slideshare.net/createwithcontext/how-people-really-use-the-iphone-presentationtype=powerpoint [Accessed 14th Jan 2009]