Ubicomp-User Centered Design

Appliance of UCD in an Ubi-comp application Mohammed Refat Chowdhury

[email protected]

Matrikelnr:#112893

Abstract

User centered design is based on the philosophy of

keeping users at the center of the software

development process. UCD is distinguished by a few

common practices such as user studies, user

feedback and user testing. Usability testing

developed for tangible user interfaces is an

emerging research area that faces various

challenges. Therefore, methodologies to seek

solution for such application have to be considered

carefully with innovative mind. This paper

demonstrates how UCD can be applied for

developing an Ubi-comp system.

INTRODUCTION

User centered design is an effective method to

design and evaluate a system from the perspective

of the user. The tools that are utilized in this

method ranges from questionnaires, online surveys

and user involvement in person. This paper reflects

the appliance of UCD in a Tangible User interface

application as well as identifies and illustrates the

trade-offs of exercising such approach.

The application context / setting – identifying the

problem and needs

The application area that I have chosen here is to

combine different automated domestic facilities

that are currently available and to integrate them

into our regular life using Ubi-Comp technologies.

The idea is to coupling the digital information into

physical form with the help of an intuitive

interaction style. In present, we have TV, music

system, security system, cameras, social networking

services scattered in our houses and we need to get

trained separately based on gadgets interfaces in

order to access them. And different level of users

often gets puzzled using the devices which have

become almost unavoidable in respect of our social

life. The proposed system is called “Super

Window” which is controlled by a laser pointer

remote controller that allows users to manipulate

interface without having special knowledge about

interaction. This system includes the most

necessary gadgets such as Television, music system,

primary and secondary cameras both for security

and capturing events, social networking and buddy

trackers, display wallpapers with some special light

effects. All these facilities are fitted into the regular

windows at our home and these windows are

connected to each other. When we are inside the

house our visibility is limited by the walls and there

is one way to extend our vision that is by looking

through the window. So, the reason behind

choosing such system is to offer general users a

context aware system with natural interfaces [2].

A technical solution sketch

The multi-functional Super Window is aimed to

facilitate its users accessing the interface by a laser

pointer controller to keep the interaction as natural

as possible. By making the application context-

aware, it can be immersed into our regular life. The

automated cameras are designed to capture live

experiences based on past events as well as users’

specified mode.

One of the features of this system is Television

which can be designed in a way to sense the

desired programs based on the historical visits or

skip to another program during commercial breaks.

The surveillance cameras are equipped with the

intelligence that they can be operated themselves,

for example, if someone breaks into house it can

connect to local police station automatically and let

them watch the incident or the user can keep an

eye on the baby sleeping in the other room or

check out what is happening outside the house. In

essence, seeing the unseen makes you exist

everywhere. The buddy program is at the users

fingertips to locate the family members. Social

networking interface can play a role to keep in

touch with the family members for an instance,

parents can be always connected to their children

no matter where they live; hence, make them feel

like living in one house or a user can use it as a

means of conferencing with other members for a

collaborative work.

The system is also able to keep displaying current

weather and perhaps, suggesting dress that can be

worn or taking precautionary measurement in case

of imminent natural calamity. Exposing fake

sunlight with different levels of intensity from the

window to make you feel the day time which could

useful for countries where the sun is visible for only

a very limited period of time. However, some of the

features of this system might be a challenging task

to implement.

For cameras, the single biggest challenge is being

able to determine the focus of attention for the

group, and more difficult, for each individual at a

live event. Accessing images later can be difficult in

case of large scale database where users often can’t

remember time and date of the images that they

require. Hence, to put them in order the users

might need to spend a good chunk of time.

Coupling context aware part with natural

interaction could be another difficult part to deal

with.

Interpreting User-centered design for this scenario

To begin with the User-centered design, it is

necessary to identify and understand the

stakeholders and their needs. The proposed system

offers the facilities which are accessible to all kind

of users independent of age, sex, geographical

location and professional background. However,

design can be commenced by taking into

consideration that the users have different level of

learning ability and their characteristics can be

documented based on their cognitive system and

socio-psychological background. These can be

gathered by observing their way of dealing with

current tools and new products. Data can be

collected using focus group method where a group

of different stakeholders are brought to a meeting

for discussion. Using questionnaires method in

combination with focus may produce better result.

A description of environment such as technical and

physical can be included into the documentation as

well in order to specify user requirements. After

defining the target customers, the current systems

that are offering the similar facilities need to be

studied as this will help users and designers to

compare current system and the proposed system

so that they can determine their requirements by

focusing on what exactly need to be simplified. The

next step is to analyze users’ tasks and goals; it’s

the way how they perform tasks with the tools they

currently use [3]. Based on their experiences and

problems that they face, we can enhance the

usability of the system and the operations more

user friendly even to new users. The method that

can be used to perform this analysis is to get the

tasks prioritized and a close observation on their

procedure to perform the tasks. This approach

would help more than relying on what users say as

sometimes it differs from the way they actually do

it. It will also shape the design strengths and

weaknesses from the perspective of competing

with other products. Now, the next step is to work

thoroughly on the collected information and specify

the requirements. Requirements specification

keeps the users and the designer stick to the goals

[6]. In this part we focus on the following

requirements:

Data Requirements

The proposed system deals with a large scale of

database, so the designers have to understand and

clarify how data can be accumulated and fetched.

This will help to design database well to integrate

with functions and keep a good flow of information.

In this system, the database is built on personalized

users’ experience and the relationships between

the entities are mostly ‘one to many’. In addition,

keeping the track of date and time associated with

users’ activities is another field to be considered

with great importance. In essence, we have to

include all the data that are available in the

environment in order to produce a context aware

system. For example, user identity information, log

of activities for particular component of the system,

personalized data based on history, updated

information on user location, trained up data for

object or face recognition used to categorize

captured images .

Environmental Requirements

In general, the issues involved with environment

have a significant impact on designing interfaces to

communicate with users. In this case, the technical

environment includes the hardware that the user

will interact with for example touch screen, laser

remote controller, speaker and microphone,

operating system in which the application will run,

software environment such as java can be used to

develop the application. In this case, the “nearby”

classification of metaphor has been used to design

the physical outlook of the system where output

takes place near the input [1]. The reason behind

choosing such metaphor is to support industrial

designers to an extent who prefer not to have any

metaphor all [2]. The physical environment consists

of atmospheric environment as the screen will be

fitted as a regular window where the temperature

has to be controlled using special screen, visual

environment has to be leveled according to the

user’s posture, the mode of the interface can be

changed based on commercial and domestic places

so that the users’ find the application more

relevant, outside camera need to be protected

from the damages caused by the atmosphere, the

level and type of sound have to be detectable for

different purposes such as baby’s movement,

children location outside expected range, friends or

parents willing to communicate.

Functional Requirements

At this stage, we have to figure out how the functions of the application are going to be accessed by the user. In this application the functions can be the television, cameras, social networking, buddy tracker, image viewer, and lighting effects. Now, we have to discover how these functions can be implemented to support users’ workflow and this can be determined by following the steps that the users’ normally feel flexible to accomplish a task. In our application, all the components are quite familiar to all users to an extent such as television with thousands of channels and millions of programs but the question is how we can manage all the programs that we are interested in and bring them all into a single channel. This function can solve the problem by taking input from the user or by tracking the time spent on programs and channels as well as the frequency of visits which may consider the users’ aesthetics and socio-psychology background. Cameras function should work as the users’ eyes that depend entirely on what they want to see. The cameras are supposed to keep watching outside and inside and sense any object movements in its range and display the changes instantly. They also can be able to capture images on its own by putting it on to an automatic mode which might be helpful during any special occasion. Social networking service is to connect people and facilitate communication as well group activities. In this module we make the interface accessible by graphical tools so that the user can understand it without referencing any manual and group activities can be promoted by board games where grandchildren will find a good cause to spend more time with their grandparents for an instance, talk room for current affairs which will generate different topics that the users might be interested in. Buddy tracker will have graphical map to represent the location of all the connected people based on mobile devices. Different colors can be

used for different ranges, for an example, children outside school perimeter can show a red alert caution sign and a beep sound as well. Image viewer has to act as regular picture albums but intelligence underneath such as face detection, timeline is used to categorize the images. Lighting effects include artificial sunlight also known as full-spectrum lighting to simulate sunlight where natural sunlight is not available. The intensity of the light is controlled by a virtual dimmer and the timer is set to switch on the light.

Another important part is to synchronize the functions so that the features can communicate each other well and in order to do so we have to look for the gap between the current user interface and the users’ need. In present, we have all the above mentioned functions being offered by the different applications from several devices but they are not interconnected. As a result users’ have to enter the same data separately for particular application of a device. For an instance, the image viewer is connected to the camera and the buddy track has to interact with social networking.

Usability Requirements

We can make the interface more user-friendly by taking direct approach that makes appearance inviting actions aesthetically. Therefore, perceptual motor centered design is more desirable than data centered as perceptual motor capabilities of human beings can lead to highly developed usability with aesthetic satisfaction [1]. This function is practiced repeatedly as it entirely depends on the users’ flexibility with the interface. However, the interface has to be efficient enough to accomplish the goals with few or no errors, the visual navigational tools have to be simple with comprehensive help and error messages. In essence, anything that irritates users should be kept modifying until user satisfaction is obtained.

User Experience Requirements

These requirements are specified by the users’

pleasant experience; something that amazes the

user. For example, the user switch on the TV in rush

to see the desired program and she finds it without

changing the channel or may be some amusing

pictures that the camera has taken on its

automated mode. These requirements can be

gathered by observing such features in the existing

applications and then letting the users have

experience on the prototype. Some other methods

such as one-on-one structured interviews, focus

groups, and ethnographic observations may be

proven effective as well.

Design

Using the specified requirements analysis we can

establish an initial design framework for the

application. In this framework, the core part is the

database which has to be handled by the

programmers where the data will be gathered from

the users through an interactive interface. The

preliminary database design can begin based on the

data that we need to store considered in data

requirements. A dataflow diagram will be necessary

to visualize the data flowing from one function to

another. However, we might need to keep changing

it in the iterative process which involves both

internal design reviews and collecting data by

observing people work with and review the

application. One of the robust attribute of this

system is to eliminate input of the same data

repeatedly as it integrates several available

applications that are already present in the market.

For example, the data for social networking and

buddy tracker should not be duplicated, hence,

avoiding data redundancy. In order to make the

appearance of interface inviting actions

aesthetically, the database should include entities

to store data of users’ activities. For an instance, if

the user watches a specific program every Sunday

at 7pm then system should sense it and should put

that channel on if the user just turn the TV on or

simply can suggest that program without creating

disturbance while watching any other program.

Using the data flow diagram we can look for and

identify the entities to store and classify the data so

that we can relate them properly. There could be

some entities for storing the tools for presenting

the interface based on users’ social psychology

background as the product can be launched

worldwide. These tools might be identified at the

goal and task stage and more specifically while the

users’ will be observed working with prototypes.

Now we have to design an initial interface considering all the requirement analysis we have done in the research and analysis part. There are various ways to commence this process, however we can start with looking at the applications that the users’ are already using and trying to visualize the conceptual model as it will help us to find the missing components that we might include in our interface. Then we can proceed with the navigational design where a careful selection of buttons and colors are required to make the visibility and accessibility of the interface more appealing, although these attributes might keep changing in the iteration process. Next, we have to sort out the functions of the components as to how they are going to be presented to the user in order to keep the natural flow of the operation. For this, we can use the card sorting method where a participant is given an unsorted pack of cards. In each card there is a statement written on it that relates to different pages of the interface. For example, the statement could be “Would you like to check out the location of your children while you are watching a movie?". Based on the answer we can figure out a way to navigate to the buddy programmer presented with the location of the children. The participant is asked to sort these cards into groups and then to name these groups. The results of multiple individual sorts are then combined and analyzed statistically. Hence, we can be assured about what and how the users are more likely to roam around. Another method to assist design process is called participatory design [7] where users can be involved actively in the design and the decision making process. Using this method we can always be in touch of information regarding what people say, think, do, use, know, feel and dream. In this workshop developers, designers and the users work together to design an initial prototype.

For prototype we can start with low fidelity paper

based prototype to help making initial design. In

this prototype we can check out the input system

flexibility how the users’ would like to interact with

the interface icons. For example, the magnetic

selection process could make the users’ feel more

confident about their selections or if they like to

scroll down for more options instead of turning

over a page for more selections. Moreover, we can

get the feedback from the user as to how they feel

about the physical appearance of the product by

touching it and moving around. In the iteration

process we can move to the high-fidelity prototype

by making a web based interface where users’ from

various regions can interact with it. This prototype

will be a modified version of the paper based

prototype considering all the updated requirement

specifications using HTML, java script and flash. The

user will have better view of the application with

the user colors, screen layout, fonts, response time

and interactive behavior. However, the

functionality is limited and more like to be task

oriented. In this case, the best thing would be to

apply horizontal prototype as this approach would

let us observe the interaction with all the functions

but not in depth. As we would be able to figure out

the perfection of the response from the user in all

components, it will accelerate the progress of the

real application. Later, we can go for vertical

approach which will let us bring more perfection to

the user interface.

Evaluation

Iteration is a key to building a successful application

in UCD. Evaluation is the most important stage

where the design is shaped into its desired form.

Therefore, we need to follow some systematic

methods to evaluate the prototype and then using

the data to improve the design of the application in

a recursive manner to achieve the goal to identify

problem areas and testing to solve those problems.

The tests need not to be complex but to be tailored

to keep up the development and minimize cost. So,

in order to evaluate the prototype we need to set

up a structure to organize our work and this can be

done using five steps as follows[9]:

Step 1: Plan and preparation:

A test plan includes list of questions which depends

on the level of testing. It is the best to have a form

ready based on test objective, testing procedure,

profile of target user, test questions. This process

will make the communication between the user and

the requirement specs more comprehensive.

Step 2: Select Participants.

Selection of potential users depends on the type of

test such as formal or informal. The informal test

can be done with co-workers, friends and family

members. Testing with the users’ who are not

related to the workforce is more important and

they can be recruited by ad online, temp agencies,

or college campus.

Step 3: Conduct test.

The personnel responsible for conducting the test

have to explain the process, the task list and he has

to play a role of observer to take notes on their

activities.

Step 4: Analyze results.

The notes taken in the previous step have to be

processed and stored properly including the

summary report written just after finishing the test.

The report should contain the details of difficulties

and problem areas along with explanation.

Step 5: Develop recommendations.

The recommendations should be based on all the

information taken before. The focus has to be on

improved user experience and can be divided into

short or long term goals. It may include information

about the given task, reason for problem, and

recommended solution.

Before heuristic evaluation and usability testing we

would like to focus on navigation map that deals

with users’ manipulation of their viewpoint to move

from one page to another. If the user cannot

successfully navigate, it affects all user tasks as it

involves object manipulation, selection, querying,

response and aggregation. Although, this

evaluation can be started based on assumption but

it becomes precise as we perform heuristic

evaluation and usability test.

Heuristic evaluation

Expert heuristic evaluation technique will be

required to be performed by a human factor

specialist who has little involvement in the project

[8]. In this case we will follow the following general

principles of heuristics [Nielson and Molich 1990].

Visibility of system status

A page of the system should carry the information

of its status, so that the user can know where he is

and what other activities are available in course of

time. For an instance, if a user gets into the settings

page then he should know the status of the page by

looking at it.

Match between system and the real world

The system has to present its attributes in a familiar

manner such as languages, words, phrases,

concepts what makes the user interact in a natural

way. This will facilitate the user from different

social psychology background to have an

aesthetical control.

User control and freedom Users’ must have a good control of the system and

freedom to move to relevant state. For example if

the user is playing games online then he should

have the way to exit instantly without have to go

through an extended dialogue and move to the

main page.

Consistency

The words, situations or actions that we use in the

application should be consistent and recognized as

conveying unique properties.

Error prevention

There should not be any error messages rather than

the system should be redirecting the user from one

page to another or suggest on what to do if any

function is not available. For an instance, if there is

any connection problem such as internet or

broadcasting, it can show a message to check the

settings or the hardware. In the worst case, it

should display the main page.

Recognition rather than recall

The interface must not put stress on users’ head to

remember the actions or options. The instructions

to use the system should be visible and

understandable easily without making any notes.

Aesthetic and minimalist design

The system should not contain any dialogue or

information which do not seem to relevant to the

user. In addition, the information must be brief but

effective.

Help and documentation

Help and documentation must be in plain language

and should be written in an interesting with the

snapshots. They can be interactive using the real

interface. For an instance, if the user wants to learn

how to play a game or capture an image, the help

can be provided using the arrows and pointing out

the objects.

Usability testing

According to Rubin and chisnell, the compilation of

usefulness, efficiency, effectiveness, learning ability

and satisfaction equate to usability. So, the target

of our testing is to find the compliancy with those

attributes. We have to plan and prepare the test for

the users who are not involved with any job that

requires high level skill or education as any one is a

potential user of the system. Separate forms need

to be maintained for test plan, the results and

analysis followed by recommendations. We can run

testing in laboratory or in the real field with real

end users and record all critical incidents,

comments, observations, impression and measure

mental work load. Then, formative evaluation can

be done for a group of users’ using an interactive

system for their opinions and more precise critical

incidents. The summative evaluation with two or

more groups can be effective to measure the users’

experience with electronics devices and compare

the performance to analyze the data with applied

statistics. The aim is to choose the best system. Test

can be done based on appropriate task

environment where real end user and tester can

work together to observe the changes in actions

placed in different surroundings and record data

using questionnaires.

Challenges and opportunities

Even after careful design and elaborated

evaluation, there are number of challenges that the

developers may need to deal with discussed as

below.

Challenges in capture

Capturing images with single fixed angle will not be

able to capture all parts of a live experience, even

with auto-rotate featured cameras it might be

difficult to find a way to make it rotated based on

the moving object. Hence, one of the biggest

challenges here is being able to determine the

focus of attention for the group and even more

difficult for each individual at a live event [5].

Challenges in access

Accessing images can be very difficult in case of

large scale database where users often can’t

remember time and date of the images that they

require. Hence, to put them in order the users

might need to spend a good chunk of time [5].

Challenges in security

The operating system must be highly secured as

this system stores very personnel information of

the user. So, if the system gets hacked then an

outsider will have access to all the information of

the user which is most undesirable.

Challenges in data input method

Data input using the laser pointer remote controller

can be difficult to use by some users’ as they have

to select characters on the virtual keyboard. In

addition, using the keyboard for some languages

such as Chinese, hindi, bangla could be more

difficult to use. A pie input method could be better

solution here [ref: textinputmethod.pdf] but still

subject to pass evaluation or perhaps we have try

with other methods which might be one of the

biggest challenges for this application.

Challenges in aesthetical design

The design may be culturally constraint. If the

design is aesthetically acceptable by one culture

that doesn’t mean that it has to be accepted by

another culture. However, it has to contain the

properties of connectivity and accepted throughout

all the people from different cultural background.

So, conforming to the users’ from that point of view

could be really difficult. In addition, the objective of

the design is to avoid tree and menu structure and

deploy an intuitive interaction style within an

affordable cost. Therefore, the interaction should

be based on man’s skill such as cognitive,

perceptual motor and emotional skills and carrying

out designing that deals with human motor

capabilities could be subject to a challenging task.

Finding potential test users

Employing users’ for test could be very difficult as

this system is to be used by anybody and involving

users’ from different social background may require

adhering critical approaches. Moreover, online

surveys wouldn’t be an effective method to

evaluate components as a large number of target

customers are not familiar with internet facilities.

Connectivity

In some countries, internet is not still available

greatly to all kind of users or probably people are

lagging far behind from using fast internet

connection. This is considered to be a hindrance for

using some features of the application as this

problem largely affects data downloading time and

quality of streaming media. Therefore, how to deal

with various network conditions must be taken into

consideration in a usability study.

Discussion and conclusion

Usability studies collect a wealth of information

aimed to discover how users work or trying to

understand the issues that users have working in a

system. One of the objectives of UCD is to produce

a proper functional system but the system may

unsuccessful upon implementation if it is not

integrated into the culture of its target customers

diligently. This could lead the achievement of this

system to a total disaster if it is not built

considering the greater context to which it belongs.

We also have to consider that usability from

developers perspective may differ to a great extent

from usability perceived from user’s point of view.

However, developing a system by considering

anybody in general is not an easy task. The problem

and challenges may exceed the capability of the

workforce and enhancement will force the budget

to be increased. So, cost-benefit tradeoffs play a

major role in the adoption of UCD methods. For

example, heuristic evaluation is relatively easy and

less costly, whereas field studies are expensive in

comparison to other methods [6].UCD offers

iterative design and it keeps repeating unless the

design meets its perfection or sees wide acceptance

by following usability techniques. And usability of a

system is depicted based on target user

requirements or what makes them feel about it.

Hence, UCD approach produces a system which is

customized for every single user of the application.

Therefore, it raises the question that to what extent

the UCD would be successful in this regard as entire

development hugely dependent on field studies. A

solution is to integrate agile methods in order to

minimize the iteration of the process [4]. Agile

developments short iterations can be used for

testing when basic UI prototype has been

approved. In this process, every cycle is a working

version of the system with limited functionality.

This procedure helps the specs to be more correct

as it is tested with users. So, UCD blending with

agile methods can be able to ensure the production

of a successful application in relation to large

projects.

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