HCI for People with Disabilities
 

Description/Abstract

This article deals with the Human Computer Interaction(HCI) of people with disability and how the designed system can assist the disable person. This issue of disable people is currently becoming the interest of both the expert and non-expert population in the field of HCI. The introduction focuses on the clarification that what is HCI, how it is related to disabled people in aspect of communication, its requirement and importance. After that dimensions and types of disability is defined which ultimately leads to the requirement of having the solution of disability type in field of HCI. Solution of four major disabilities (i.e., visual, hearing, physical and speech disability) is explained that what kind of system is required for the concerned problem and how a related person can use it. References/Sources are mentioned at the end of the Article/Blog.

Introduction

Human-Computer Interface (HCI) is the study and development of computer based interfaces with the express purpose of making them convenient, simpler, easier and productive for the human. We can find applications and devices inferring new concepts of HCI. It is about designing new systems (specifically computer systems) that support human so they carry out their deeds productively and safely. It attempts to study new modes of communication that could be used for human computer communication and simultaneously to develop devices and techniques to use such modes. The technique devices can be used for communication with the human and in the same way human can communicate with such techniqued devices using their perceptual abilities, processes and organs. The serious and sensitive aspect of using such technology for the disabled people. They need more inclusive technology rather than having separate world(i.e., Virtual Reality). HCI is actively considering the assistance of disabled people. Human-Computer Interface (HCI) systems allows more natural communication with the machines.

What is Disability?

A disability is any condition of the body or mind (impairment) that makes it more difficult for the person with the condition to do certain activities (activity limitation) and interact with the world around them (participation restrictions). According to WorldBank.org , out of One billion people, 15% of the world’s population, experience some form of disability, and disability prevalence is higher for developing countries. One-fifth of the estimated global total, or between 110 million and 190 million people, experience significant disabilities. Persons with disabilities are more likely to experience adverse socioeconomic outcomes such as less education, poorer health outcomes, lower levels of employment, and higher poverty rates.

Dimensions:

According to the WHO, disability has three dimensions:

1.       Impairment in a person’s body structure or function, or mental functioning; examples of impairments include loss of a limb, loss of vision or memory loss.

2.       Activity limitation, such as difficulty seeing, hearing, walking, or problem solving.

3.       Participation restrictions in normal daily activities, such as working, engaging in social and recreational activities, and obtaining health care and preventive services.

Major types:

Disability has many types which affects the person:

·         Vision

·         Movement

·         Thinking

·         Remembering

·         Learning

·         Communicating

·         Hearing

·         Mental health

·         Social relationships

People with Visual Disabilities

Visual disability is one that impairs one’s vision or causes loss of vision. The main reason of assistance of HCI in this field is the interaction of disable people with computers. They can hardly read contexts of computer with their naked eyes and it also depends upon the level of vision that one find it difficult to see small icons and read small font of text. Normal eyeglasses and better interface design is the best solution for this level of vision. But for the people with extreme vision disability (who find trouble seeing large amount of text, keys of keyboard), one way is the use of system that make sounds when using multimedia. Sound multimedia helps visually disabled human to navigate through the multimedia menu and text reader helps to read the written message, screen readers such as JAWS, exist for blind people to navigate through a website. They read the text of the screen.

To perform a user's required task or activity, the user firstly needs to input the required information via some input device such as keyboard. But in case of visually impaired persons, they can not enter value or input in a normal way so new keyboard have been established to help them enter data into the system.

As the input is provided to the system with the use of input devise. Computer monitor is the component where the entered information has been displayed to see or get the output. So to ease this, the screen magnifiers have been developed to magnify the content of the screen.

Such a system should also have an option to zoom in and zoom out text feature or change of the text size so it becomes convenient for vision impaired people to read the content and context. Meanwhile, proper color contrast should be used (prominent between text, background and graphics) for color blind people. In other words, system with screen magnifier is better for such people but not for completely blind persons though having said they need a system with screen reader.

People with Hearing Disabilities

Hearing loss, deafness, hard of hearing, or hearing impairment, is defined as a partial or total inability to hear. Audio commonly used for feedback and situational awareness. Many such people with this disability cannot express themselves clearly in public as they  cannot  use  speech  as  a  medium  of  communication,  yet  a  large  part  of the hearing population cannot communicate with the deaf because they do not know sign language.

Sign  Language  is  the  main  communication  medium  of  the  hearing  impaired or deaf people. In order to assist such people with hearing disability, a system is required which can help people with hearing loss one way is  through auto transcription. Increase use of captions in video can help their accessibility. In most cases, websites or products have speech or video based clips. In this scenerio, speech/audio clips should have transcript and videos should have captions available. In this way, not only those with hearing impaired people are benefitted but also other users (like if someone is new in that language or one is travelling in a noisy environment i.e., bus, train so this can be helpful for both). Introducing Gesture-based interfaces can be somehow better for such people.

Having said earlier sign language is the better medium of communication for such people. Infering this knowledge, a new technology (which is still in its early stages of innovation) is Sign Language Recognition and Synthesis. It uses computer vision techniques to convert sign language videos into the spoken or written form. A hearing disabled person can wear a glove having sensors connected, and make gestures of sign language which will be converting to the spoken or written form. In the same way sign language is synthesized with gestures and can make a video visualisation though the system is not certain completely.

People with Physical Disabilities

A physical disability is a physical condition that affects a person’s mobility, physical capacity, stamina, or dexterity. This can include brain or spinal cord injuries, multiple sclerosis, cerebral palsy, respiratory disorders, epilepsy, hearing and visual impairments and more. People with physical disability have limited control over their body. Fine mouse movements, keyboard usage or any precise motion is difficult for them. For devising a system for such users, one can think of speech input rather than keyboarding. Head pointer technology (demo image is displayed below) can also be considered if motor control of extremities is greatly impaired

People with physical impairment have difficult precise motion than other technology user do when using components of system. For this, the system should be made least precision as possible. For example, buttons with mild hit should be triggered and enhancing the button's hit area. In case of interfaces, the designs should not be closed up too close as the probability of hitting wrong target is greater in physically impaired people.

People with Speech Disabilities

People who cannot speak or having difficulty in producing sounds fall under the class of speech disability. Such people only have a lack in slow communication as the medium of their communication is typing or writing. Spoken communication is far more faster than typing/writing. Such people can also use sign language and its technology to communicate. To make their communication more faster, common communication auto text suggestion is recommended in system which is already available in most of the system in this era.

Conclusion

It is necessary to say this research blog/article has its limitations. The first limitation is that the people has wide classification in sense of disability and they are further divided into sub-classes so it was not possible to mention all so a generic research based blog is made. HCI has always been characterized by the successful fallout of technologies from one application to other ones. Its technology getting innovated and improved according to the better concept. We live in an imperfect world and hence we should design products to be used by everyone with various different flaws, backgrounds, disabilities, and experiences. Technical developments in HCI allows us to be optimistic in forseeing the overcoming barriers to gain access to computer and through them to technical networks.

References

https://www.cdc.gov/ncbddd/disabilityandhealth/disability.html

https://medium.com/@kalyan.vejalla/hci-for-people-with-disabilities-979b6371467b

https://blog.google/products/android/braille-keyboard/

https://www.disabled-world.com/disability/types/hearing/

https://www.mdpi.com/2076-3417/9/18/3790/htm

http://parkinsonsdysarthria.weebly.com/aac-assessment.html

What is Loop?

Loop Statements

Types of Loop Statements in C

1. 'while' loop
2. 'do-while' loop
3. 'for' loop

Control Variable

'while' Loop

The syntax of 'while' structure for a group of statements is as follows:
                   while (condition)
                  {
                            group of statements ;
                   }
                   next_statement ;

Flowchart of 'while' Loop

Following is the flowchart of 'while' loop structure:

While loop diagram

The switch Statement

Flowchart Switch Statement

What is Median ?

Median In Un-Grouped Data

       Even

Median of Ungrouped Data Formula of Even Number

Median of Ungrouped Data Formula of Odd Number

Median In Group Data 

        In this method we have given class intervals and frequency we simply solve this using formula.

        Formula:

Formula of Median in grouped Data

Median of Un-Group Data Code / Program in C /C++

#include<iostream>

using namespace std;

int main(){

int num;

float x[10],sum=0,mean,temp[10],Oloc,Eloc;

cout<<"Enter Total Number ";

cin>>num;

cout<<"X"<<endl;

for(int i=0;i<num;i++){

cin>>x[i];

}

cout<<" Given Data is: ";

for(int i=0;i<num;i++){

cout<<x[i]<<", ";

}

for(int i=0;i<num;i++){

for(int j=i+1;j<num;j++){

if(x[i]>x[j]){

temp[i]=x[i];

x[i]=x[j];

x[j]=temp[i];

}

}

}

cout<<endl<<" Arange : ";

for(int i=0;i<num;i++){

cout<<x[i]<<", ";

}

cout<<endl;

if(num % 2 == 1){

Oloc=x[num/2];

cout<<" Median of Odd Data is "<<Oloc;

}

else{

Eloc=(x[num/2-1]+x[num/2])/2;

cout<<" Median of Even Data is "<<Eloc;

}

return 0;

}

Input

Odd Data

Enter Total Number 9

X

5

7

9

8

3

2

1

6

4

 Given Data is: 5, 7, 9, 8, 3, 2, 1, 6, 4,

 Arange : 1, 2, 3, 4, 5, 6, 7, 8, 9,

 Median of Odd Data is 5

Output

Input

Even Data

Enter Total Number 8

X

5

1

2

9

7

3

2

4

 Given Data is: 5, 1, 2, 9, 7, 3, 2, 4,

 Arange : 1, 2, 2, 3, 4, 5, 7, 9,

 Median of Even Data is 3.5

Output

Median of Group Data Code / Program in C /C++

#include<iostream>

using namespace std;

int main(){

float num,sumf=0,median=0,sumCF=0;

float start[10],end[10],f[10];

cout<<" \t\t <<----- Median Of Grouped Data ----->> "<<endl<<endl<<endl;

cout<<"Enter Total Number ";

cin>>num;

cout<<"Enter Class Intrvals"<<endl;

for(int i=0;i<num;i++){

cout<<i+1<<"- Range Start ";

cin>>start[i];

cout<<i+1<<"- Range End ";

cin>>end[i];

}

for(int i=0;i<num;i++){

cout<<i+1<<"- Enter Frequency of this Range ";

cin>>f[i];

}

int CF[10],loc,index;

float CBStart[10],CBEnd[10];

for(int i=0;i<num;i++){

sumf=sumf+f[i];

CF[i]=sumf;

CBStart[i]=start[i]-0.5;

CBEnd[i]=end[i]+0.5;

loc=sumf/2;

}

for(int i=0;i<num;i++){

if(CF[i]>=loc){

index=i;

i=num;

}

}

cout<<endl;

cout<<"Class Interval Frequency Class Boundaries Cumulative Frequency"<<endl;

for(int i=0;i<num;i++){

cout<<start[i]<<" - "<<end[i]<<"\t\t"<<f[i]<<"\t\t"<<CBStart[i]<<" - "<<CBEnd[i]<<"\t\t\t"<<CF[i]<<endl;

}

float l,h,f1,c;

l=CBStart[index];

h=(end[index]-start[index])+1;

f1=f[index];

c=CF[index-1];

cout<<endl;

cout<<" Lower Class Boundary (l) "<<l<<endl;

cout<<" Hight (h) "<<h<<endl;

cout<<" Frequency oF Location (f) "<<f1<<endl;

cout<<" Sum of Frequency (Sum(f) "<<sumf<<endl;

cout<<" C (C) "<<c<<endl;

cout<<endl;

median=(l+(h/f1)*((sumf/2)-c));

cout<<"Median = l+(f/n)*((sum(F)/2)-c) = "<<median;

return 0;

}

Input

Enter Total Number 5

Enter Class Intrvals

1- Range Start 2

1- Range End 4

2- Range Start 5

2- Range End 7

3- Range Start 8

3- Range End 10

4- Range Start 11

4- Range End 13

5- Range Start 14

5- Range End 16

1- Enter Frequency of this Range 6

2- Enter Frequency of this Range 3

3- Enter Frequency of this Range 9

4- Enter Frequency of this Range 10

5- Enter Frequency of this Range 12

Output

What is Mean ?

Here n is the total number of X.

Program in C / C++

#include<iostream>

using namespace std;

int main(){

float x[10],num,sum=0,mean;

cout<<"Enter Total Number ";

cin>>num;

cout<<"X"<<endl;

for(int i=0;i<num;i++){

cin>>x[i];

sum=sum+x[i];

}

cout<<"Sum: "<<sum<<endl;

mean=sum/num;

cout<<"Mean = Sum(x)/n = "<<mean;

return 0;

}

Input: 

X: 5, 10, 15, 20, 25

Output: 

Mean in Group Data

    In Group Data, we have given data Class interval and frequency (f). Formula of mean group data.

Step 1: Find X of every index.

X= lover Class interval + Higher Class interval /2

Step 2: find F*X.

we simply multiply every index f*x and Sum of all F*X.

Step 3: Sum of F.

Program in C /C++

#include<iostream>

using namespace std;

int main(){

float x[10],fx[10],num,sumf=0,sumfx=0,mean;

float start[10],end[10],f[10];

cout<<" \t\t <<----- Mean Of Group Data ----->> "<<endl<<endl<<endl;

cout<<"Enter Total Number ";

cin>>num;

cout<<"Enter Class Intrvals"<<endl;

for(int i=0;i<num;i++){

cout<<i+1<<"- Range Start ";

cin>>start[i];

cout<<i+1<<"- Range End ";

cin>>end[i];

cout<<i+1<<"- Enter Frequency of this Range ";

cin>>f[i];

}

for(int i=0;i<num;i++){

sumf=sumf+f[i];

x[i]=(start[i]+end[i])/2;

fx[i]=f[i]*x[i];

sumfx=sumfx+fx[i];

}

cout<<"Class Interval Frequency\tX\tF*X"<<endl;

for(int i=0;i<num;i++){

cout<<start[i]<<" - "<<end[i]<<"\t\t"<<f[i]<<"\t\t"<<x[i]<<"\t"<<fx[i]<<endl;

}

cout<<endl;

cout<<"Sum(F)  = "<<sumf<<endl;

cout<<"Sum(FX) = "<<sumfx<<endl;

mean=sumfx/sumf;

cout<<"Mean = Sum(fx)/Sum(f) = "<<mean;

return 0;

}

Input:

Class Interval  |  Frequemcy

5-10                 |          8

11-15               |          16

16-20               |          2

21-25               |          5

26-30               |          10

Output