Human-computer interaction (HCI)
A taxonomy of human-computer interaction
Human-computer interaction (HCI) is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use, and with the study of the major phenomena surrounding them.
Chapter 2 of the ACM SIGCHI Curricula for Human-Computer Interaction which provides a useful introduction to and history of human-computer interaction.
Activity theory: an introduction
Activity theory originated in the USSR, developed by Russian psychologists Vygotsky, Rubinshtein, Leontjev and Lurija. The theory is a philosophical framework that allows the study of different forms of human practice. The practice can be viewed as developmental processes where both individual and social levels are interlinked. Activity theory can be used to provide a broad conceptual framework that can be used to describe the structure, development and context of tasks that are supported by a computerised system. Activity theory offers the possible integration of many HCI theories and concepts, thus helping to maintain conceptual integrity in terms of design, evaluation and usage.
A day in the life of HCI
When I speak to some smaller firms about HCI, I often get a response on the lines of, "that sounds great, but we only have one or two projects so there isn't really enough work for a full-time HCI." On some days, I have a lapse and actually nod in agreement. On other days, I think back to some projects I've worked on and recall how I spent all of my time on a single project from requirements to release and not only had enough work - I had too much work. Certainly, underestimating the amount of work a job takes is nothing new. Programmers have had to live with managers under allocating time for development and testing for years. In HCI, however, the difference isn't by days, it's by months. How is such a massive disconnect possible? To answer this question, I decided to look at what a typical project cycle was like for me, and what tasks I did.
A few thoughts on cognitive overload
This paper examines two issues that arise when we set out to design real life environments in which multi-tasking, interruption and cognitive overload are the order of the day: What is cognitive overload and how can an understanding of the cognitive workflow in environments lead us to design better workspaces?
Alan Newell assesses HCI and the health of the discipline
Alan Newell claims a sideways perspective on HCI, having used strategic components in his work of developing applications to help people with disabilities for decades. His department at Dundee numbers 37 researchers, ranging from specialists in linguistics, social work and psychology to computer programmers, speech and language therapists, a teacher, a nurse and a philosopher. He might also claim a longitudinal view: he has been involved in the business since 1968. And he's still in it, remaining passionate, restless and full of opinion.
Banner blindness, human cognition and web design
Benway and Lane have studied "Banner Blindness" (ITG Newsletter, Dec. 1998: 1.3) – the fact that people tend to ignore those big, flashy, colourful banners at the top of web pages. This is pretty interesting stuff, for the entire reason they are so big and obnoxious is to attract attention, yet they fail. Evidently nobody ever studied real users before--they simply assumed that big, colourful items were visible. This paper, shows once again the importance of observations over logic when it comes to predicting human behaviour.
CHIplace is an online community site for people working in the field of human-computer interaction. It includes disussion forums, job postings, conference information and book reviews.
Data you can virtually touch
Is haptic technology, which allows users to "feel" virtual objects, finally ready to come out of the laboratory? Haptics is the science of simulating pressure, texture, temperature, vibration and other touch-related sensations. The term is derived from a Greek word meaning "able to lay hold of". It is one of those technologies much loved by researchers, but rarely seen in commercial products. In the laboratory, haptic systems are becoming increasingly sophisticated and capable. William Harwin, the head of a haptics-research team at the University of Reading, believes that such systems are now ready for much wider use.
Exploring the mnemonic user interface (PDF)
The manner in which files are visually organised, all according to the popular desktop metaphor, concur with conditions
applicable twenty years ago. Over time, these conditions, technical as well as user oriented ones, have radically changed. The desktop metaphor has not. This article is an offspring of personal reflections over too much time being spent traversing file structures and organising windows in the user interfaces of today’s modern operating systems.
Greg Edwards on design and content optimization through eyetrack testing.
Fitt's law and text links
This article demonstrates a method for increasing the size of text links without altering visual presentation.
Fitt's UI law applied to the web
The basic idea in Fitts's Law is that any time a person uses a mouse to move the mouse pointer, certain characteristics of objects on the screen make them easy or hard to click on. The farther the person has to move the mouse to get to an object, the more effort it will take to get to. The smaller the object is, the harder it will be to click on.
Fitts' law: the missing mouse factor (PDF)
The mouse is a superior input device, and will be for many years to come. But as computer screens grow larger and larger, targets become increasingly harder to hit. Many interaction designers tend to take 'increasing the target size' as the solution of the problem--all according to Fitts' law. But Fitts' law only accounts for target size and distance--not mouse sensitivity. Increasing the target size as a means of making targets easier to hit defeats the sole purpose of larger screens.
F-shaped pattern for reading web content
"Eyetracking visualizations show that users often read Web pages in an F-shaped pattern: two horizontal stripes followed by a vertical stripe. F for fast. That's how users read your precious content. In a few seconds, their eyes move at amazing speeds across your website’s words in a pattern that's very different from what you learned in school."
(Jakob Nielsen - Alertbox)
Hands across the screen - why scrollbars are on the right and other stories
"Why are scrollbars on the right, and is it the best place for them? There are good reasons to think that the left-hand side may be the better choice, but in virtually every interface since the Xerox Star the scrollbar has appeared on the right-hand side. In this short paper we'll look at this issue and also at the design of a browser several years ago, which raised similar issues in the placement of on-screen buttons. In both cases, the best placement does not look right when you see it statically, but feels right when it is used. The reason for this discrepancy is an aversion to virtual hands across the screen."
How many items should go in a menu?
This article explains why Miller's "magic seven" does not apply to navigation or menu design.
(Alan James Salmoni)
Human error and the design of computer systems
In 1988, the Soviet Union's Phobos 1 satellite was lost on its way to Mars. Why? According to Science magazine, "not long after the launch, a ground controller omitted a single letter in a series of digital commands sent to the spacecraft. And by malignant bad luck, that omission caused the code to be mistranslated in such a way as to trigger the test sequence". Phobos went into a tumble from which it never recovered. What a strange report. "Malignant bad luck"? Why bad luck: why not bad design? Wasn't the problem the design of the command language that allowed such a simple deviant event to have such serious consequences.
Information foraging: why Google makes people leave your site faster
The easier it is to find places with good information, the less time users will spend visiting any individual website. This is one of many conclusions that follow from analysing how people optimise their behavior in online information systems.
Interfaces for staying in the flow
Psychologists have studied "optimal human experience" for many years, often called "being in the flow". Through years of study, the basic characteristics of flow have been identified. This paper reviews the literature, and interprets the characteristics of flow within the context of interface design with the goal of understanding what kinds of interfaces are most conducive to supporting users being in the flow. Several examples to demonstrate the connection to flow are given.
Intuitive equals familiar
One of the most common terms of praise for an interface is to say that it is "intuitive" (the word should have been "intuitable" but we will bow to convention). Yet the Human Computer Interaction (HCI) literature rarely mentions the word, and for good reason. This note attempts to clarify the meaning of "intuitive" for non-HCI specialists.
Narrative vs control in the online story world
"How much control should users be able to take over the system they are using? Within HCI, the challenge is usually to give control of technology to users; be it through accessible design, or, more generally, by making paths clear and choices apparent. But the question becomes more complex when considered in the context of learning, when the users are students."
Report: Aesthetic approaches to HCI
"This is a report of the NordiCHI 2004 Workshop on Aesthetic Approaches to Human-Computer Interaction, which took place in October at the University of Tampere."
- Syntactic knowledge and visual knowledge
The traditional way of interacting with a computer needed what Ben Shneiderman calls "syntactic" knowledge. The graphical user interface has substituted syntactic for visual knowledge. Each one has its own advantages and drawbacks.
The culprit behind limited working memory capacity
What does a snapshot of human cognitive architecture show- a sensory system allowing us to take in a lot of information from the world, a vast long-term memory store and a severely limited working memory store. The limited working memory store represents a bottleneck in human cognitive processing. Two recent studies published in Nature show that the brain area related to the capacity limitation of memory capacity has finally been located!
The evolution of user-centered focus in the human-computer interaction field (PDF)
We offer a historical perspective on the development of the human-computer interaction (HCI) field over the last 20 years. In that time many changes have occurred in how we think about making use of data gathered from users of technology to guide the process of designing and developing new hardware and software systems.
The next GUI - maybe LUI
Over the years there have been a lot of articles and discussions about the need to replace the antiquated Window/Mac WIMP (Windows, Icons, Menus and Point Device) style user interface with something more modern and user friendly. Over the next few months through a series of postings I'm going to explore one possible direction for the computer user interface. It is a design that is based on the observation that computers are fundamentally about information and tools.
The underlying thinking of how people learn, acquire knowledge, and understand
The field of instructional design and technology is valuable to the UX community, providing theories and knowledge on important aspects of human behaviour and the role technology plays influencing that behaviour. Two theories on how people learn with (information) artifacts we design, 'instructionalism' versus 'constructionism', are directly germane and very valuable for the UX community.
What is Fitts' Law?
Fitts Law is a robust model of human behavior which enables the prediction of human movement and human motion based on rapid, aimed movement other than drawing or writing. In Human Computer Interaction (HCI) Fitt's law is a useful guideline in interface design.
Why do current graphical user interfaces not work naturally and how can they be fixed?
"Squares and rectangles have been used as a primary interface shape for millennia. Just think of all the things you use on a daily basis that are rectangular: books, magazines, televisions, computer monitors, spatulas, soda boxes, parking slots - everything around us seems to be square... I think the time has come where people want a new, more efficient, different way to interact and control these tools. In nature, the strongest shape is the arch, or circle. Throw out your built-in biases towards rectangular screens. What if screens were round?"
- World's first HCI rap - "we got it"
A rap song with an HCI theme.
A breakdown of the psychomotor components of input device usage
"This study investigates the breakdown of the psychomotor components of three different input devices, the mouse, trackball, and RollerMouse using the Stochastic Optimized Submovement Model. Primary movement time (PMT), Total Movement Time (TMT), Primary Movement Distance (PMD), and Total Movement Distance (TMD) were examined for each device. Results showed that psychomotor variables related to the primary phase of movement help to pinpoint how performance efficiency is affected by a particular device. For example, the relationship between %PMD and efficiency suggests that a device that affords users an initial accurate movement decreases the need for more or longer corrective submovements, thus reducing movement time."
A psychological study of banner blindness on the World Wide Web
Banner advertisements are a major source of revenue for many internet companies, and yet recent reports suggest that "click-through" rates have fallen alarmingly. Why do users not click on banner advertisements? The phenomenon of "banner blindness" suggests that many users simply fail to notice banners. To test this claim, we designed a series of web sites, and inserted banners that were either useful for performing a task or were not useful. Even though clicking on the target banners would assist users with the tasks they were asked to perform, such behavior was almost never observed. Only half the users reported noticing the banners, and only 10% of users thought that the banners were ever useful. Rates of banner click-through were not affected by a manipulation intended to test covert attentional processing.
Banner blindness: web searchers often miss obvious links
Web guidelines usually recommend that to make an important item stand out, it should be near the top, and be large and/or brightly coloured. One item separated visually from everything else on a web page may be completely ignored by web searchers, even by searchers who are deliberately searching for the information provided in that item. Designers should be cautious about following guidelines stating that increasing the visual distinction between "important" items and other items is desirable; the visual distinctiveness may actually make important items seem unimportant.
Ergonomic mice: comparison of performance and perceived exertion
"This study reports a psychophysical comparison of four ergonomic mouse-type devices to the standard mouse. It was hypothesized that muscle activity transferred from the distal to proximal limbs for some of the ergonomic mice may result in increased load on the shoulders and declines in target acquisition performance. Results revealed a potential tradeoff between performance and safety with the devices as participants performed the best with the standard mouse but reported more wrist exertion with this device."
Ergonomic soft mouse and armrest mousepad
In this paper, it is shown that a teddy bear skin spongy mouse is a better option than a conventional plastic mouse design and that a portable arm rest mouse pad platform is far better than the conventional mouse platform placed to the side of the keyboard tray. Both designs help reducing arm abduction and related discomfort, pain, fatigue and soreness.
Just how 'blind' are we to advertising banners on the web?
In our study, we were curious to simply explore how much users remember about a web page after viewing it--in particular, we were interested in investigating user memory of banner advertisements.
Measuring the user response to ClearType
Two studies on user response to ClearType, a setting that is manipulated through the operating system of devices using Liquid Crystal Display screens. ClearType works by altering the vertical color stripe within a pixel, allowing for changes in how the text looks at fractional levels. These changes are intended to enhance the resolution of the screen text and improve readability.
Online banking: why people are branching out
Results from a questionnaire designed to query online banking behavior are reported. The most frequent activities reported were checking account balances and viewing or paying bills. Purchasing insurance, CDs, and applying for a loan or credit card were the most infrequent online activities. Respondents indicated that convenience and saving time were the biggest incentives to bank online. Quick access to information, clear feedback, and simple terminology were identified as the most important features of an online banking site. Implications for designers of online banking sites are discussed.
Paper or pixels: what are people reading online?
This study evaluated the reading habits of Internet users across five document types - journal articles, news, newsletters, literature, and product information. Internet users completed an online survey indicating how likely they were to read a document online or on paper. Journal articles were primarily reported to be read in printed form, while documents such as online news, newsletters, and product reviews were reported to be read mainly online. Users reported that they tend not to use online sources for reading literature. Primary factors determining whether a document was printed or read online were size, importance, and intended purpose of document.
The mentality of homo interneticus: some Ongian postulates
Because typical experiences will differ, the mentality of the typical Internet user, or Homo interneticus, is likely to be significantly different from that of the typical reader of printed works or of writing or of the typical member of purely oral cultures. These differences include deep assumptions about time and space, authority, property, gender, causality and community.
When search engines become answer engines
The website is becoming a less prominent locus of experience as people use search engines to bring up answers to their current questions. How can sites cope with masses of freeloaders?
Why are users banner-blind? The impact of navigation style on the perception of web banners
It has been observed that contradictory results have been found regarding the perception of banner advertisements on the Internet. While some studies found that recall and recognition scores for banners were at a satisfactory level, others observed that banners are almost generally overlooked. In this study, it is argued that the opposing results might be explained by differences in navigation style (aimless browsing versus goal directed searching). To test this hypothesis, 32 subjects were presented with a Web site containing a number of banners ads. Half the subjects were asked to search for specific information, while the other half was instructed just to explore the site as they wished. In a subsequent recall and recognition test, subjects from the aimless browsing group performed significantly better than subjects from the information search group. Results are discussed with regard to the supposed underlying processes of perception and information processing.
- A quiz designed to give you Fitts
So you think you are an interaction designer? Not if you cannot answer all the following questions quickly and with authority.