Human Computer Interaction

The text provided is quite lengthy, but here is the rewritten version with proper punctuation and sentence breaks:

---

It means that how a user interacts with any system is fine. It must be the computer. I don't have to interact with the computer. How a human or a user interacts with any system, or how the interaction will be better, is what we will read in this chapter.

Now you may ask, "Madam, why do we read it here?" Because here, you are building up a system. Now, what you are building in the back end of a system is what the user sees in the front end. What that front end will be like is the main focus of this chapter. The focus is on how user-friendly my front end or interface should be to explain the usability of my system to the user.

The first term is "task." Look below.

What does "task" mean? A task is the work I want to do. Now, you are a system analyst. If you develop software for an organization, that software development is your task. According to the task, which is relative to a user, the task he would do offline, now that task, when you convert it online or put it through a system, becomes your task. The user's task was to perform the work online. When you have completely computerized that work, what will be the user's task? Then, what will become of the offline computerized system? Now, his task is to explain how to use that computerized system.

Before you intervened, the user's task was to do a manual task. You are a system. What did the computer do with the manual task? Now, the user's task is to fulfill the computerized task. By "computerized task," we mean a task that the user will perform. Fit. Now, look at the figure and notice that there are three points to understand the fit: one is human, one is computer, and one is task. If these three align properly, then I can say this is a fitted job. It is with the help of which you will do the work, and the task is your work.

A little earlier, what does "task" mean? This is the task which is this human.


Well, hello everyone. Is there everyone? Is there? Wait a little, ma'am. Wait a little, ma'am. Yes, yes. Is anyone out? Turn off everyone's mic. Wait a bit, ma'am is joining.

Yes, Rumel, ma'am. No, your screen is black. No, ma'am, turn off your microphone, Rumel.

Sir, I can hear you, ma'am. Ma'am, I understand the task. The next point is performance. Well, now let me give an example. What is fit? Because you know the answers now, you know the answers to the questions, you can definitely write them well in the exam. Then, what will happen? Your performance will be good. Same goes for the work you are doing on the computer. If you do the work well, then your work output or performance will be good. And if any work you can complete well is better for your mental health.

Because, suppose you have gone to the exam and you know the answers, but you are not able to perform properly or write properly in the exam book, then will not your mental condition be better? But the questions you can do, if you can write the answers correctly in the notebook, your performance will be good as well as your well-being can be ensured because you will be happy in your work. You can answer the questions exactly as you are reading. Be well.

So, when you become a system analyst and computerize a task for a user, you have to keep three terms in mind: one is fit, one is performance, and the other is well-being. He is fit to do the work, his performance will be good, he will be mentally happy. Now, you understand what the work is. I hope I can explain it. Now, here is the work of the system analyst. Where is the work of the system analyst? To implement these tasks according to the satisfaction of the user, so that the user can understand. If the user understands what to do and how to do it, then those tasks will be fit for him. Then, you can increase his performance and well-being.

It is very important in the test that these questions come up: how fit, performance, and well-being are related. Well, the next point is the Technology Acceptance Model (TAM). Well, it's very important to listen well. TAM in full form is Technology Acceptance Model. What does TAM really mean? Remember the name Technology Acceptance Model. You judge how the technology you are giving to a user is accepted by this model.

The technology acceptance model is the system that I am giving to the user. It must be a computerized system. There will be a technology. I will measure how my user accepts or can accept the system well with the technology acceptance model. Well, now there are two points to measure: one is Perceived Usefulness, and one is Perceived Ease of Use. Listen carefully.

The same task that would take you an hour to do manually, if you do it with a computer system, it will take you five minutes to do. Then, he can perceive what he did. Even if you say it verbally, you can explain it by making a prototype. How to explain it is completely up to the system analyst, but if you can explain it, then the user will accept your system better.

You didn't show any prototype at all about the end product that you gave to the user. Now, the user doesn't understand anything when he sees your system. He will be more upset that his previous system was good. He used to work manually before; at least he understood the work. Now he has been given a system. He doesn't understand anything. How can he use it? But he didn't accept your technology. You have to give some effort to make him accept your technology. You have to explain to him that you can do the same work more easily than it took you to do the previous work. How to use my system? How to use this is how you have to use it like this.


The next point is perceived usability. "I was able to complete the work. There will be no mismanagement of my data. My data is protected in a database. When I need the data, I can extract the data very easily. If there's a computer system in the database, I don't need to remember it. I'm just searching for it." This should tell you where the usefulness of this computer system is. Your technology will be more readily accepted.

Now, you may be asking, "Why do I need a TAM? Why do I need a technology acceptance model?" Because if you have an idea about the mentality of your users before you start working, you will understand what kind of software you need to build for them. Did you make your user study? Did you not know or understand what kind of knowledge the user has about the software? You did not try. You made a very complex system of your own. Then what did the user do? He tried to use your system for two days. He did not understand anything. Then he did not use your system anymore.

Or, you could not be a good developer. Whether your user can accept the technology you are developing properly, before developing the technology, you need to check how much my user's knowledge about the technology is, how much training he has, and my technology or what I want to offer. He will accept these things before your user starts working. You have to understand from the user how to understand. If you ask how to understand, then it will not happen. Judge or measure how he will accept your technology, good, bad, fair, and if he accepts, how much training he needs. You will judge from here. I hope I can understand.

Well, the next point is usability. Its usability is okay. What you are doing now, what you are doing is building a system. The system you are building has some functionalities. If those functionalities are usable for my user, then I can say that your system has usability. Okay, break it down a bit more. If you say you are building a system for CUET, for this system of CUET, you are keeping 100 functions. Out of these 100 functions, you are thinking by yourself that yes, an educational institute needs such and such functions, and the remaining 40 are taken from the user. When the user uses 40 of those 100 functions, those 40 are usable for him. The remaining 60, which they did not say, are not usable for him because they were not in his requirement. So the usability of your system will be what I mean by a system. Usability is defined by the user requirements of that system. If you can fulfill the user requirements, your system is usable. I hope you can understand.

The next point is designing for cognitive styles of individual users. It says a lot. I gave a lot of data or asked to collect data that I told you to contact various system analyst companies and bring their monthly salaries to me. Very well. Then, I told you to create a report and give a presentation. Now, when you create the presentation slide, you can represent this data in different ways. You can show it in table form, you can show it in description form, you can show it again using different charts. There are different tools for you to show them. So this point is to use different cognitive styles when you are going to explain something to the customer. If you show different histograms or use tables to show the data, it will be convenient for the user to understand. It will be convenient to compare. You should use such styles. You will use whatever kind of tools you need to use in order to be able to convey.


Well, see the next point, Physical Considerations of HCI Design. Physical Considerations. Physical Considerations. What HCI Design stands for is Human-Computer Interaction Design. Its short form is Interface Design. Now, when creating an interface for your system, you will think about how your interface will look and whether the interface will look good to the people who will use it. You don't keep in mind, of course. Now assume you're building a system for a company. There are some people in the company who cannot be color blind; some cannot see the color red, some cannot see the color green, or cannot differentiate with other colors. Now, you are creating an interface where a color-blind person can see which font of that color. If not, then when you use that system with him, will he be able to use your system well? Because the color font that you are using is not seen or can't be seen by that particular user, in his respect, your system is not good because you didn't consider his physical condition.

No, what is his physical condition? Can I explain color blindness in a particular color? So, when you design a system or create an interface for a company, you have to keep the physical conditions of the employees of that company in mind. Suppose an employee is impaired; he can't type. He has some kind of problem with his hand. So, what will you do? Give him speech recognition software. What can he do through speech? Given command, your system will work according to that command you made for him. I am giving an example. OK, again, the color vision cannot identify any colors. You should avoid those colors and design your interface. It is a system that considers the physical condition of the employees of an organization. There is a way to find out. The way to find out is to interview them—if you are color blind, if you have color vision problems, or if you are physically disabled, if you have typing problems, or if you have hearing problems. These things you already know.

If you take it from a closer look, it is not possible to design the system for each different person. It takes a lot of effort. You should think about the majority and make it as easy as possible for those physically impaired people to design your interface.

Next comes Implementing Good HCI Practices. Good HCI Practices. What are the five points here? What task means, what you have to implement, you have to examine well. When to examine the system requirement, what to do in the system specification, how to do it, examine everything, then consider the fit of the human, computer, and task. For you, it will fit; you have to think whether it will actually fit or if it would be better to do it manually. You start the task by thinking Identifical Exist for Usermine. I said my tasks, which he was doing offline before; he was doing it manually while doing it. Identify the type of subscale or obstacle that fills the problems so that those problems are not present in your computerized task. If there is, then there is no difference between your system and the manual system. Examine the previous system so that the previous system does not exist in this system. Identify the problems. Eradicate them.

Keep in mind Perceived Usefulness and Perceived Ease of Use for this. As I said a little earlier, the problems of the previous system, Ease of use of the new system, Obstacles of the previous system, Usability of the new system, Think things through, and build your technology acceptance model. Explain to the user. If the user accepts, then go to the prototype. Consider Usability. Is it that we will create a model? Through the model, we will understand how the whole system will function. Why should we do it? So that there is no redundancy between the functions of the system. If there is, then the usability of your work is reduced. Redundancy is there by determining how the user interacts with the technology or system. All you have to do is that you can accommodate, but try to do the maximum.


A summary of what I have read before. If I summarize in two lines, what will happen? Which task I want to computerize? My user will be able to use it easily. If the user accepts my technology, then what will I do? I will check the physical conditions of other people in the company and make a model of the interface. Then, I will go to design the prototype. I am reading how to create a model, how to implement it. Now, we are doing the previous work. What happened? We are gathering the requirements. By gathering, we are seeing whether these requirements are usable. If it is usable, will it help my user? Instead of the previous manual work, now the computerized task is to help the user. After determining whether to do it, I will go to work.

Well, now let's come to the types of user interface. So why do we need the user interface? How can we explain to the user that yes, if you use it like this, the work will become easy for you? Now, let's see what types of user interface there are.

Interface you understand very well. Natural Language means what language we speak in Bengali language. Now, if there is any interface in Bengali, we will call it a Natural Language Interface for us. Only if there is an interface only in Bengali, then it is called a Natural Language Interface. It can't be said that you have to query in the Bengali language. Like you have such a system that you told the system, "How many districts in Bangladesh?" It gave a direct answer: 64 districts. Maybe that would be a natural language interface. I'd talk to that system the way I speak. If you could interact with a system the way you talk to your friend, that would be a natural language interface. It's still not possible to have a 100% natural language interface, no, because it is a very complex task. Because a system sometimes interacts with different people. Only the way you talk to it, it will give you an answer. It is a very difficult task. It is not possible to do it 100%.

Question and Answer Interface. Do you think that you are typing something in Microsoft Word Office and not saving after typing? When you cross, a box does not appear? The dialog box does not ask you if you want to save before you quit. You are asked a question; you are given two options for the question: yes or no. It is a question and answer interface. Actions will be taken according to your task. This is the question and answer interface. There are different clickable buttons. These buttons are a menu, then point form fill interfaces. You also understand that before doing any work or before logging into a system or before logging into a website, what do you do before filling different forms or taking different information? One type of interface which is called a form fill interface.

Well, next is the Command Language Interface. Take a look at it. Behave. You are reading a database. You are not writing a query in the database. One command is okay. You are giving one command. You are writing a query. According to that query, it is showing you data. You are giving a command; the interface is behaving accordingly. This is a Command Language Interface. Clear now? You can say that, "Madam, then what is the difference between the Command Language Interface and the Natural Language Interface?" In the Natural Language Interface, you are typing in oral language, and in the Command Language Interface, you have to follow a specific rule. You have to remember that format and write it accordingly. Then it will give you the data you want. Command Language Interface must have specific syntax. As I am speaking, I will answer the question as per my question. I hope the system will give me an answer.

PC is an example of GUI. If you use Ya, what is it called? Windows use Windows. Windows is an example of that. You just execute your commands graphically. It asks no Ya from you, no question, no question, no question, no answer. It doesn't show you some icons. You use that interface by clicking on icons. When there is such an interface, we will call it a graphical user interface.



Well, there are also different interfaces, like touch screens. It is also a type of interface that you touch the screen. Taking response from OK, new and more interfaces are coming; it is written here.

Well, now you see, you are making the interface as you like. OK, now I talked about so many interfaces to make a website. With a single interface, but a website does not become your form fill interface. You need the interface of the dialog box; it means the interface of question answering. You make a system by combining different types of interfaces. The number is "Necessary Training Period for Users Acceptably Short." Does it mean that the interface you are building for the users is the interface that the user can use in a very short time, meaning that he needs less time to train?

Command Language Interface means write direct query, and it will phase the data. Now, the boy is a commerce student or an arts student. Whatever, you tell him to memorize the syntax, memorize the syntax, you will give the command, and then it will give you the answer. It is not feasible. If you give him 10 years, even if you train him, he will not be able to remember it. Not even a computer science engineer can remember it. He will forget it; it is normal. It is not feasible unless he is a direct analyst or developer whose job is to write commands or write queries. It's easy for him to remember because that's his job.

Now, if you tell me instantly, I won't remember how to write this query. So, don't use an interface that takes a lot of time to train the user. Well, point number two is keeping interfaces consistent throughout applications can help in this regard. Well, I'm just reading the last line. Keep the interface consistent from the log-out page to look the same. Navigation bars are in the same place on a page. Navigation bar at the top of a page. Navigation bar at the bottom of a page. Your login has the option to log out. If you go to another page, there is no option to log out. One page has the option of the home page. If you go to another page, there is no home page option. This cannot be done so that errors are few and don't occur because of poor design.

Means your design can't have any effect. Clear? Now design can't have faults. When you are coding the interface, there is very little chance of making a mistake in your design or your interface. Check if it is free. Point number four is the time that users and the system need to bounce back from errors. This is a bit important. Is your user using your interface? Now suppose you have a sign-up page or a registration page. Where he will set a password, and then he will confirm that password again. This means the same password must be given in two places. Now, the password he gave in the first field goes to the second field; he does not give the same password. It means he is making a mistake. Now, if you don't catch this thing immediately, what will happen when you go to the next one? Your system will be wrong because he has given two types of passwords in two places. Which password will your database accept? So, here the error is not the user's error, but this error should be caught by the user immediately so that he can fix the error immediately because otherwise, later, the user will find it difficult to go and use your system.

Number point: Infrequent user system quickly. What does this mean? Suppose you are building an e-commerce website. I used your website today, and after a year, I will go and use your system again. OK. So, in a year, I won't remember your system. I won't remember where you were. I won't remember what things are on the website. When I come back and use your system a year later, I can quickly see at a glance where the options are in your system or where I can find my desired product. I can understand that the time I spend searching your system the first time I use it and the second time I use it, I don't have to spend so much time chasing your system. You should also keep this in mind so that the user can adapt to your system very quickly.

Look at these five points while creating the interface, but very important if you miss any of these five points, then I will say that your interface is not user-friendly. Until now, we have been saying that making a user-friendly system, making a user-friendly system, this is what a user-friendly system is.


For creating a good system or a good interface, the first point is meaningful communication. Meaningful communication means two words: one is "meaningful," and the other is "communication." First, come communication. Here the communication is between the user and the system so that this communication is done properly. That's what a developer has to do.

Now, what exactly do you mean by that? The system should provide what the user wants. OK, then this will be meaningful communication from the user's perspective or not. Understanding my question and answering it correctly is meaningful communication between you and me. Now, I don't have to explain what I want from you for the question I'm asking you or the answer I want from you. If I can't explain it to you correctly, I want this answer from you. Then do you understand me or not? Then I can't communicate meaningfully with respect to you because I can't understand you properly. I am from you.

What do I want to answer from? Clear? Now put "user" and "system" in these two places. The user wants data from the system. Now the system has to provide it. If he can provide it, then it is meaningful communication in respect of the user. Now, the system needs to understand the data he wants first. If it can understand the system properly, then it will be able to answer it correctly. OK, now do you write "date of birth"? Do not write DOB. You are new generation people. What do you like to use? Short form. Now, you write DOB in one place on your website, date of birth. Now big people like me don't understand them well. We are old generation; we don't understand that DOB stands for "date of birth." Now, if the system can't tell the user that DOB stands for "date of birth," then it won't be meaningful communication. So, the user has to understand that by this I mean your date of birth.

The website should be written in such a way that whatever information you have to give to the user to understand while using your website, the developer will provide the user through the interface. Then, you can establish meaningful communication. For example, if you are clicking a button, after clicking the button, you have to wait for a while for the information to be processed or the function of the button you are pressing. The system is executing one instruction after another, so it has to give you some time. Now, you are clicking, the system is not giving you any feedback. You think it is not taking your click. There's no communication going on between somebody. You're pressing a button, the system has to tell you to wait a while, your job is done, then you don't press the button anymore, you wait.

It wants to understand the system and feedback accordingly, and this work will be the intermediary of the developer. Means minimal user action means that the user who is using a system should do very little work to complete a task. Well, our time is very valuable. If I am computerizing the manual work for Laga, then surely I have to reduce the time here. Now, to reduce the time, user action has to be reduced. Now, there are some points to reduce the user action. In different ways, you can reduce. Here are some points mentioned. If you see them, then you will have an idea which action they are about.

The first point is "King Codes." Let me give an example. Suppose there are many airports in Bangladesh. Now, you want to go to the USA. That is, you want to go from Dhaka Airport. You will go from Hazrat Shahjalal International Airport. Now you have Dhaka Airport, Chittagong Airport, which airport do you choose? If you have to write this directly in the field from which airport you will fly while buying the ticket, then the user will not have to type a lot of things. Instead of typing the full name of the airport, if you say that it is Dhaka airport, you press one or the code of Dhaka airport. Zero zero, Chittagong airport code is zero zero two. Then, what should he write in that field? Zero zero or zero zero two? Writing the code is easier than writing the name of a whole airport, so anywhere you can write different names. What do you do? The user will select the airport by mapping it with that code, and then you can reduce the user's actions.


Point number two is entering only data that is not already stored on files. It is very important that the information is already in the database. The second time, you do not take it from the user. During simple registration, you take the full name from him, and then there are various other information, taking his address, taking this many things. Now, after registration, every time when he goes to log in, will you not take the same information from him again? You will only take a username and password from him. Which information is already in the database, don't take it from him anymore. If you have to type the information like registration again to log in to a system, then it is not a good system. Then, you have to give the previous information again. It takes more time. Time should be reduced. Ok, keep that username unique, give that unique user code. He can collect his previous information from your database.

Point number three: supplying editing characters. Do you think you are taking date of birth from someone now? Date, then month, then year. Now, there are two slashes in these three fields. Now, you can input these two slashes by yourself if you want, or you can leave it already built-in in the system because it must be like this: then slash month slash year. You will keep these slashes already built-in so as to trouble the user again. They don't have to be typed.

Point number four is using default values for fields on entry screens. Well, do you think you are making a website for CUET? Okay, now for registration here, users or students need to provide a lot of information. If there is an input or there is a field which is common for all, which will be CUET for all. Suppose what you can do is you can block that field already, or if that field is already a default value, you can give it. For example, CUET this and give your fill to the user. There is no need to do it, but if he wants, he can write something else instead of CUET. You have put the option of deleting it and writing something else in case if needed. But since the majority will write that CUET, you can already write the default CUET. So what happened to the majority of the users here? Don't waste time writing CUET.

Point number five: designing an inquiry program so that users need to enter only the first few characters of a name or item description. This is any. If you are building an e-commerce website where any user searches for any product name. Now, let's say someone is looking for a shirt. If someone writes "SH," and then the suggestions of that product will automatically come up with "SH," then he can press two keys and then he can go to his desired page with just one button or one click. I can explain to him, and the whole "SHIRT" did not start typing.

Point number six: providing keystrokes for selecting pull-down menu options. This is also important. Suppose you are building an e-commerce website. Now, suppose you want to buy a variety of products for boys. Now, what about boys? When you click on the "men's collection," another drop-down menu will appear. It can be a shirt, pants, suit, different types of drop-down menus. After that, he had to click again on the desired product there. Now, since you have given more pull-down menus, if he clicks on "men's," he gets a few more options. He can go to direct shirts or go to direct pants, okay, with two clicks he goes to the page he needs.

Point number seven: use radio buttons and drop-down lists to control displays of new webpages or to change web forms. This is what I said a little earlier. Plus, what will happen with the radio button? Your gender will either be male or female. You can give a radio button here that either press male or press female. You don't need to write direct male or female.

Point number eight: provide cursor control for web forms and other displays so that the cursor moves to the next field right after the number of characters have been entered. Can it be date of birth you are inputting? OK, now your day must be two digits. Now, as soon as you input two digits, it will go to its next field. That means month two. As soon as he inputs the two key of the field, he will move to his next field. Year is year. As he inputs four of the four fields, he will go to the next field, next inquiry, next query. He will go there. That means where your specific number of keystrokes, you can take an answer from the user, in which case you can set it so that after those few keys are pressed, then he will go to another field automatically and accept more than two characters or more than three characters in this field or in that specific field. No, if you give it, then the user does not have to click on the next field by repeatedly turning the pad or moving the mouse. The reason for this is to minimize the user action.

This is when you develop a system, then you will understand yourself where else, if you minimize the user's actions, my user will not board using this system.