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Lab 2.1 Exercises

2.1.1. Identify the Main Components of Human-Computer Interaction

a) Name the three main concepts of human-computer interaction and discuss their relevance to HCI.

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A1:

Answer: The human, the computer, and the interaction between them are the three main components. It is the human that is inputting the data. Humans are intrinsically different from computers as well as from other humans. Therefore, how they affect and relate to the system determines how efficient and useful it is. The computer or hardware needs to be able to process the input that the user wants. If a user wants to input speech, but does not have sound card, the desired interaction is not possible.

b) Which of the three components of HCI is the most important and why?

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A2:

Answer: The human. Humans only use computers as enabling devices that help them carry out necessary tasks.

2.1.2. Identify and Understand the Goals of Human-Computer Interaction

a) HCI is concerned with the whole system of how humans and computers interact with each other. Consider the components mentioned in the text and discuss how they affect the behavior of the whole system.

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A1:

Answer: The computer hardware and software, the user, and the environment in which the HCI takes place are the four main components of HCI. How each component of this (or any) system interact are key aspects of how the system behaves as a whole.

The type of hardware you have, and how well the software processes input through the hardware are important aspects of HCI. The first character-based terminals that provided direct interaction to the operating system were a lifesaver for programmers and operators. Having the hardware to input the data and the software (a command shell) to interpret the input and react accordingly increased efficiency dramatically. Although the first GUI was seen as nothing more than an interesting curiosity, today we cannot image a computer without a windowing system (GUI).

Since it is the user that is interacting with the system, he or she is a vital part of the system. The psychology of seeing, cognitive abilities of the user, as well as physical limitations are important parts of the human side of the interaction. Even personal preferences play a role.

Ergonomics has grown from a buzzword to a key component of HCI. Products are being marketing based on their ergonomic characteristics and I have worked in companies where a pamphlet on ergonomics was part of the welcome packet.

Consider the myriad of devices available that support HCI. Depending on the system you work with most, the first thing that comes to mind is either the keyboard or the mouse (perhaps the monitor). The keyboard must be able to input the characters you need into the software. People in different countries require different characters to do their work. Even between countries with the same language there are differences. For example, the U.S. keyboard does not have a key for the British pound (£). Imagine the impact on efficiency if a person in a bank in Britain had to work on a U.S. keyboard!

However, the symbols written on the keys are just half of it. The signal that a particular key sends is dependent on its position on the keyboard and not what is printed on it. Most modern operating systems have software (keyboard drivers) that you can change to behave differently. Therefore, when you press a particular key in the U.S., a different character appears on the screen than would appear in Britain or Germany. Without this particular software, what is printed on the keys can be different from how the software interprets the key being pressed. Imagine pressing the “y” to answer “yes” to a question and have a “z” appear.

Also, so-called “natural” keyboards are sold whereby the keyboard is split in half and the halves are turned slightly so you can place your hands in a more natural position, so ergonomics plays a role here.

The introduction of the mouse increased our efficiency by allowing use to send information to the computer system without have to remember (let alone input) long commands. Technological changes in mouse design have also increased efficiency, such as the introduction of multiple buttons (the first only had one button). Trackballs can also increase efficiency because you don't have to deal with space issues on your desk, cleaning out lint from the mouse ball, and so forth. Even the physical shape of the mouse has been changed to fit more comfortably into your hand and make it easier to use.

Other technologies, such as voice recognition and text-to-speech as a combination of both hardware and software, have increased the efficiency of computers. How well the software can process the input (i.e., accurately recognize the words or produce understandable speech) greatly effects the system as a whole.

Not only can interaction be provided in situations where you need your hands for other work, such components that allow people to interact with the computer who could not before (for example, quadriplegics and the blind). Even the shape and position of these input devices has become an important aspect of them (ergonomics once again).

b) Describe one of the major roles carried out by HCI specialists.

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A2:

Answer: Any one of the following:

  • Understanding psychological, organizational, and social factors of the combined human and computer system

  • Developing methodologies to aid appropriate HCI design

  • Realizing efficient and effective interactions for single users and groups

c) Considering the historical influences, why do you think HCI specialists need to study from several other disciplines?

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A3:

Answer: HCI specialists need knowledge about the human brain and other senses, how humans behave, the ability to communicate and perform, how to design user interfaces for these human characteristics, and how to evaluate those user interfaces to determine whether the criteria have been met.

From Table 2.1, you can see that many areas have contributed to the skill set required of HCI practitioners. Note that while the mainstream computing areas like computer science, information systems, and operating systems play a significant role, other, quite distinct disciplines like ergonomics and psychology play major roles, too.An HCI specialist is therefore quite a unique person with a carefully designed set of skills.
d) Visit the sites www.startrek.com, home.netscape.com, and www.irs.com. Discuss how each is designed (does it remind you of anything?) and how well the information is presented (can you find what you are looking for?).

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A4:

Answer: Both the Star Trek and IRS sites have user interfaces that are very typical for Web sites and that adhere to the issues we discussed in Exercise 1.7.2. There is a head, a single menu that links to other areas, a central block with the important information, and a footer area with links to more “administrative” areas of the site. Both sites fit a specific paradigm. In the case of the Star Trek site, it is designed to look like a control panel from one of the series, using the same styles and fonts. The IRS site is designed to look like a newspaper, including the headlines. On the Star Trek site you can quickly tell that it is a site about Star Trek. However, it is a lot harder to figure out that the IRS site is about the U.S. Internal Revenue Service and not some company coincidentally named IRS. Even so, in both cases you can easily find the information you are looking for.

On the other hand, except for the logo, it is hard to tell that the Netscape site has anything to do with the company. In fact, this is really not the best place to look for information about the company Netscape. Instead, the page provides you information about everything else on the Internet except for Netscape. Part of the psychology of the Internet is that when you want to find out information about a company, you input www.companyname.com and there you are. With the Netscape site, you actually have to look hard to find information about Netscape (such as product information or technical support). In addition, there is simply too much information on the page (at least for someone new to the site). It is difficult to figure out all of that information. In essence, it does not adhere to what we discussed in Exercise 1.7.2.


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