Monk Fundamentals of Human-Computer Interaction

1. Auflage 2014
ISBN: 978-1-4832-7675-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 312 Seiten

Fundamentals of Human-Computer Interaction aims to sensitize the systems designer to the problems faced by the user of an interactive system. The book grew out of a course entitled ''The User Interface: Human Factors for Computer-based Systems'' which has been run annually at the University of York since 1981. This course has been attended primarily by systems managers from the computer industry. The book is organized into three parts. Part One focuses on the user as processor of information with studies on visual perception; extracting information from printed and electronically presented text; and human memory. Part Two on the use of behavioral data includes studies on how and when to collect behavioral data; and statistical evaluation of behavioral data. Part Three deals with user interfaces. The chapters in this section cover topics such as work station design, user interface design, and speech communication. It is hoped that this book will be read by systems engineers and managers concerned with the design of interactive systems as well as graduate and undergraduate computer science students. The book is also suitable as a tutorial text for certain courses for students of Psychology and Ergonomics.

Autoren/Hrsg.

Monk, Andrew F.

Inhaltsverzeichnis

1;Front Cover;1
2;Fundamentals of Human—Computer Interaction;4
3;Copyright Page;5
4;Table of Contents;6
5;Contributors;14
6;Preface;16
7;Acknowledgements;18
8;PART ONE: THE USER AS A PROCESSOR OF INFORMATION;20
8.1;Chapter 1. Visual Perception: An Intelligent System with Limited Bandwidth;24
8.1.1;1.1 Introduction;24
8.1.2;1.2 Luminance, Contrast and Brightness Advantages of High Luminance;27
8.1.3;1.3 Colour Sensitivity;30
8.1.4;1.4 The Visual System as A Spatiotemporal Filter;34
8.1.5;1.5 Perception as an Active Process;44
8.1.6;1.6 Summary;50
8.1.7;1.7 Further Reading;51
8.2;Chapter 2. Reading: Extracting Information from Printed
and Electronically Presented Text;54
8.2.1;2.1 Introduction;54
8.2.2;2.2 The Cognitive Psychology of Reading;55
8.2.3;2.3 Legibility;60
8.2.4;2.4 Special Problems Associated with Reading from CRT Displays;62
8.2.5;2.5 Summary;65
8.2.6;2.6 Further Reading;65
8.3;Chapter 3. Human Memory: Different Stores With Different Characteristics;68
8.3.1;3.1 Introduction;68
8.3.2;3.2 Short Term Memory Stores;69
8.3.3;3.3 Long Term Memory;71
8.3.4;3.4 Summary and Conclusions;74
8.3.5;3.5 Further Reading;75
8.4;Chapter 4. Thinking and Reasoning: Why is Logic So Difficult?;76
8.4.1;4.1 Introduction;76
8.4.2;4.2 Deductive Reasoning;77
8.4.3;4.3 Inductive Reasoning;79
8.4.4;4.4 Summary;82
8.4.5;4.5 Further Reading;82
9;PART TWO: THE USE OF BEHAVIOURAL DATA;84
9.1;Chapter 5. How and When to Collect Behavioural Data;88
9.1.1;5.1 The Value of Behavioural Data;88
9.1.2;5.2 When to Collect Behavioural Data;89
9.1.3;5.3 Behavioural Measures;91
9.1.4;5.4 Selecting Subjects;93
9.1.5;5.5 Designing Experiments;94
9.1.6;5.6 Summary;97
9.1.7;5.7 Further Reading;98
9.2;Chapter 6. Statistical Evaluation of Behavioural Data;100
9.2.1;6.1 Introduction;100
9.2.2;6.2 Testing for Differences Between Means;101
9.2.3;6.3 Correlation;104
9.2.4;6.4 Summary;106
9.2.5;6.5 Further Reading;106
9.3;Chapter 7. Example of an Experiment: Evaluating some Speech Synthesisers for Public Announcements;108
9.3.1;7.1 Introduction;108
9.3.2;7.2 Experiment One - Method;110
9.3.3;7.3 Results;113
9.3.4;7.4 Conclusions from Experiment One;118
9.3.5;7.5 Experiment Two;119
9.3.6;7.6 Summary and General Discussion;120
9.3.7;7.7 Further Reading;121
10;PART THREE: THE USER INTERFACE;122
10.1;Chapter 8. Work Station Design, Activities and Display Techniques;126
10.1.1;8.1 Introduction;126
10.1.2;8.2 Input Devices;127
10.1.3;8.3 Output Devices;129
10.1.4;8.4 Facility or Feature Selection Techniques;130
10.1.5;8.5 Display Techniques;133
10.1.6;8.6 Summary;138
10.1.7;8.7 Further Reading;138
10.1.8;8.8 References;140
10.2;Chapter 9. Dialogue Design: Characteristics of User Knowledge;146
10.2.1;9.1 Introduction;146
10.2.2;9.2 Field Studies of System Use;148
10.2.3;9.3 Experimental Studies of System Use;162
10.2.4;9.4 Application of Findings;180
10.2.5;9.5 Summary;182
10.2.6;9.6 Further Reading;183
10.3;Chapter 10. User Interface Design: Generative User Engineering Principles;184
10.3.1;10.1 Introduction;184
10.3.2;10.2 Problems in Interactive System Design: Motivation for a Better Way;187
10.3.3;10.3 Introducing Generative User- Engineering Principles;188
10.3.4;10.4 Examples of Gueps;192
10.3.5;10.5 A Warning Against Pseudo-Generative Principles;196
10.3.6;10.6 Summary;197
10.3.7;10.7 Further Reading;198
10.4;Chapter 11. Future Uses of Future Offices;200
10.4.1;11.1 Introduction;200
10.4.2;11.2 Setting the Scene;201
10.4.3;11.3 Scene One - The First Consultation;203
10.4.4;11.4 Scene Two - On Location In Camden Town Friday Morning the Next Week;208
10.4.5;11.5 Summary;211
10.4.6;11.6 Further Reading;211
10.5;Chapter 12. Speech communication: The Problem and Some Solutions;212
10.5.1;12.1 Speech as a Medium For Communication;212
10.5.2;12.2 Speech Articulation and Recognition: How Do People Do It?;219
10.5.3;12.3 Speech Production and Recognition: How Can Machines Do It?;231
10.5.4;12.4 Summary;238
10.5.5;12.5 Further Reading;238
10.6;Chapter 13. Speech Communication: How To Use It;240
10.6.1;13.1 Introduction;240
10.6.2;13.2 Machine-Generated Speech;241
10.6.3;13.3 Voice Recognition;245
10.6.4;13.4 Interactive Systems;250
10.6.5;13.5 Summary;254
10.6.6;13.6 Further Reading;255
10.7;Chapter 14. Human Factors Problems in the Design and Use of Expert Systems;256
10.7.1;14.1 Introduction to Expert Systems;256
10.7.2;14.2 How Expert Systems Work;257
10.7.3;14.3 Acquiring Knowledge From The Human Expert;260
10.7.4;14.4 Representation and Use of Knowledge By The System;262
10.7.5;14.5 User Interface Design;264
10.7.6;14.6 Summary;265
10.7.7;14.7 Further Reading;266
11;Glossary;268
12;References;274
13;Author Index;292
14;Subject Index;12

Leseproben

CHAPTER 2

Reading: Extracting Information from Printed and Electronically Presented Text

Charles Hulme

Publisher Summary

This chapter describes mechanisms underlying skills, such as memory and reading by trying to establish systematic relationships between input (stimuli) and output (responses). In recent years, there has been a great deal of research by cognitive psychologists into the nature of reading processes. Such research is generally conducted within a human information processing framework. The processes by which people read are explicitly fragmented into separate stages and the processes operating at these stages are systematically investigated in experimental studies. A major applied issue in studies of reading is to establish the way in which typographical factors may improve or hamper reading efficiency. Reading material presented on computer controlled video display terminals has its own special problems associated with it.

2.1 INTRODUCTION

In interacting with computers human operators often receive and send information in the medium of written language. It is clearly relevant for those designing and implementing computer systems to be aware of the sorts of processes involved in reading. The characteristics and limitations of the human information processing systems involved in reading will be relevant for maximising the operating efficiency of man-machine systems.

In recent years there has been a great deal of research by cognitive psychologists into the nature of reading processes. Such research is generally conducted within a human information processing framework. The processes by which people read are explicitly fragmented into separate stages and the processes operating at these stages are systematically investigated in experimental studies. This human information processing approach sometimes comes as something as a surprise to non-psychologists. Basically the cognitive psychologist views human beings mechanistically and often explicit analogies are drawn between the information processing operations carried out by people and the operations performed by computers. The aim is to try to elucidate the mechanisms underlying skills such as memory and reading by trying to establish systematic relationships between input (stimuli) and output (responses). On this basis theories are constructed which attempt to specify different stages in the system between input and output. These stages are specified in terms of the types of code information is held in and the sorts of transformations it is subjected to. The next section presents such a view of the process of reading.

2.2 THE COGNITIVE PSYCHOLOGY OF READING

An Overview of the Reading Process

Reading might be defined as the extraction of information from text; the process by which we get meaning from a printed message. There are several sub-processes which are often distinguished in discussions of this very complex process.

The reader must first perceive the visual patterns of the words on a page. On the basis of this visual information he must decode the meanings of the individual words present. This process involves going from a visual representation of a word to some stored representation of that word’s meaning. According to current theories of this process the meanings of words which the reader knows are stored in a kind of internal dictionary or “lexicon”. The processes by which the stored information in the lexicon is accessed is the subject of a great deal of research. It appears that on some occasions readers may recode visually presented words into a speech-like representation, while on others access to the lexicon occurs directly from a visual representation (see, for example, Coltheart, 1978).

Having identified the meanings of the individual words in a sentence, the reader must undertake a syntactic analysis. That is, he must relate the meanings of the individual words in a sentence according to the rules of the grammar of his language. The meaning of a sentence will depend not only upon the individual words but upon the way in which they are combined. To take a trivial example the following two sentences have quite different meanings:

The cat chased the dog

The dog chased the cat

It appears that in order to perform syntactic analyses of written messages readers hold the string of words in the form of internal speech. Using speech is a very good way of remembering the order of words, which is clearly crucial in understanding sentences (Kleiman, 1975; Baddeley et al., 1982).

The final stage involved is that the meanings of individual sentences in the passage must be related to each other to reach an understanding of the passage as a whole. In these later stages of reading the reader is clearly performing a kind of problem solving exercise. The ease of understanding a piece of written material will depend not only upon the characteristics of the passage, e.g., how clearly it is printed, its grammatical form, etc., but also upon the reader’s past experience and familiarity with the concepts involved.

Eye Movements and the Intake of Visual Information

An average rate of reading for normal adults is somewhere in the region of 250–300 words per minute. A widely held belief, which accords with our subjective experience, is that as we read our eyes sweep smoothly along the printed line. This impression is, in fact, quite false, as first shown by Javal. In fact our eyes move along a line of print in a series of small rapid jerks, which are called saccades. These saccades are punctuated by short periods, called fixations, when the eyes are still. On average, fixations last around 150–300 milliseconds, and the saccades happen much more quickly, taking around 20 milliseconds. The perception of the printed material occurs only during fixations; during the saccades no clear vision is possible. In most situations about 94% of reading time is devoted to fixations.

During the reading of a line of print the eyes sometimes move backwards towards the beginning of the line to re-read some of the material. These backward movements are known as regressions. The number of regressions is related to the difficulty of the material being read. When the material is difficult more regressions occur. When one line of print has been read the eyes make a long return saccade to fixate the beginning of the next line.

This pattern of movements is illustrated in Figure 2.1. It may be possible to observe these eye movements during reading by placing a mirror in front and a little to the right of the reader and then looking at the mirror from behind him. In current research eye movements are normally recorded by using systems which detect the patterns of reflection from small fixed lights placed in front of the eye. (See, for example Rayner, 1978.)

FIG. 2.1 An illustration of the eye movement patterns of a good and a poor reader. Numbers at the top of the lines show the sequence of fixations; those at the bottom show the time taken for each fixation in 50ths of a second.

The Perceptual Span in Reading

The perceptual span refers to the amount of text which can be processed by the reader in a fixation. Visual acuity is highest at the fovea of the eye and falls off rapidly towards the periphery (see Chapter 1, section 1.2). These physiological factors obviously place constraints on how much information can be extracted in a fixation. The problem of how to define the perceptual span in reading proves to be not as simple as might first appear. This has been most elegantly demonstrated in a series of experiments by Rayner (1975). In these studies subjects read short paragraphs displayed on a CRT display slaved to a computer. The same computer system also monitors the subjects’ eye movements by means of sensing corneal reflections. Various words in the text are distorted and changed back to their correct form as the subject moves his eye past some pre-set boundary. The dependent measure analysed is how long subjects fixate these target words, and the assumption is that if a discrepancy is noticed between the form of the word in peripheral vision and that when the word is fixated then subjects will fixate the word longer. These experiments show that if gross physical cues concerning the letters present in a word and its overall shape are maintained, for example by changing “tasted” to “tested”, these changes are only noticed at a distance between one and six character spaces to the right of fixation. On the other hand, changes in word shape, as in replacing “tasted” by “tflmed”, may be detected seven to twelve character spaces to the right of fixation. The implication of such results is that information about the meaning of the word is only being extracted from a very narrow window of text but gross cues such as overall word shape may be being picked up from much further into peripheral vision. Such a result should not surprise us, but it means we cannot talk of a single perceptual span in reading, but rather a number of overlapping spans from which different types of information are being extracted simultaneously.

Recognising Individual Words

A great deal of...