CHAPTER IX. HOW EwT/HCI, EMC AND HLC WORK TOGETHER IX-1. ALL 'PARTS' OF ONE HUMAN ACTIVITY Only very seldom, if ever, do we just interact with the computer (EwT/HCI) with absolutely no attention to the meaning of the information it contains (EMC), and with absolutely no regard for our everyday lives, such as purposes why we do things. EwT/HCI, EMC and HLC should never be seen as separate activities, but rather as three multi-aspectual human activities that are intertwined with each other. All computer use involves all three. But how do the three link and work together? That is what this chapter discusses. Loosely we might call EwT/HCI, EMC, HLC all 'parts' of HUC. But they are not parts in the way wheels, engine, body are parts of a car, or head, arms, legs, body are parts of us. Rather, they all work together and cannot be separated from each other. (For those who want to understand this more, Dooyeweerd introduced the notion of 'enkaptic' relationships to describe this, which are different from 'part-whole' relationships.) Briefly: » EwT/HCI-EMC link: In EwT/HCI, the most important aspect is the lingual, because when we function lingually we engage with what symbols mean (signify). This signification or meaning of the symbols is precisely the 'represented meaning' with which we engage in EMC. » EMC-HLC link: Engaged with this represented meaning, we are acting and doing things in real life (HLC). » HLC-EwT/HCI link: Also, as we interact with the computer, we find some real-life effects, especially in the early aspects, such as repetitive strain injury, tiredness, excitement, etc. and our actual mental state affects the quality of our EwT/HCI. EwT/HCI is often discussed first, but they all work simultaneously, not one after the other. That is why it is possible to start with any of them when learning about them. In each main section we examine one of these links, with a fourth one that looks at them all together. Each link can be high or low quality, and various researchers have proposed what the quality factors should be, or tried to understand these links. The following notions have been formulated to consider each: » §2, EwT/HCI-EMC link: Affordance and Appropriateness » §3, EMC-HLC link: Information Richness and Information Fulfilment » §4, HLC-EwT/HCI link: Errors in computer use » §5, EwT/HCI-EMC-HLC link: Cognitive Dimensions IX-2. EwT/HCI-EMC RELATIONSHIP: APPROPRIATENESS (This is the longest one.) EMC is engagement with meaningful content. The main raison d'etre of EwT/HCI is to enable the human user engage with the meaning that is represented in the computer. So EwT/HCI serves EMC and makes it possible. EwT/HCI links to EMC through one aspect in particular: the lingual. It is the lingual aspect of our interaction in which we understand or express the meaning that the symbols involved in the interaction carry. Obviously, it should do so well. That is, the interactions should be appropriate to the meaning. For example, if you want a very precise number, use digits, rather than a slider or bar chart. But on the other hand, if you want to compare several quantities quickly, then use bar chart rather than a list of digits. IX-2.1 Affordance The theory of affordance was first proposed by Gibson [1977] and applied to user interfaces by Greeno [1994]. The theory says that certain sensory stimuli 'afford' different kinds of informational meaning, rather than other kinds. To say, for example, that the length of a bar 'affords' a quantity means that it is 'natural' for the length of a bar to be used to express quantities, and natural for quantities to be expressed by lengths of bars. This is made much use of in bar charts, as in Figure 1, which shows profits of a number of companies. Note how we can easily read the bar chart as showing the profits of company C as highest, of company E as lowest, and so on; it is very natural to represent quantitative information by length. Profits | 500 | | 400 | # | # # 300 | # # | # # # # 200 | # # # # # | # # # # # 100 | # # # # # # | # # # # # # 0 |___#_____#_____#_____#_____#_____#__ Companies: A B C D E F Figure 1. Bar chart: Length of bars 'affords' quantitative information But now try to use bars as follows, in Figure 2. Look at the figure and think: what is it telling me? Towns: | | M'cr | # | # Leeds | # # | # # Glasgow | # # # # | # # # # Bath | # # # # # | # # # # # London | # # # # # # |___#_____#_____#_____#_____#_____#__ Companies: A B C D E F Figure 2. Bar chart used in a different way Here the bars indicate in which towns each company has its head office. So, for example, companies A and F are both in Glasgow, company E is in London, and so on. The information can be obtained from this, but it is not so natural as Fig 1 is. While Fig 1 uses length of bars to express quantitative information, Fig 2 uses bars to try to express relationships (the relationship between company and town). The length of bars 'affords' quantitative information, but it does not 'afford' relationship information. A better way of expressing relationship information is to use a dot, as in Figure 3: Towns: | | M'cr | # | Leeds | # | Glasgow | # # | Bath | # | London | # |____________________________________ Companies: A B C D E F Figure 3. Dot chart used to express relationships What we learn from this is that the shapes, positions and other psycho-spatial phenomena are better at expressing some types of information than others, and vice versa. Why is this? Can we understand why one is more difficult than the other? And can we find other examples of good and bad affordance? Can we find rules or guidelines by which we can ensure we design our EwT/HCI to be more appropriate? And IX-2.2 Aspects of Affordance and Appropriateness We can understand affordance via the aspects. In the EwT/HCI chapter, symbols are governed by all aspects, but how they 'work' (and how well they work) is governed especially by the three aspects before the lingual, namely the formative, analytic and psychic aspects, on which the lingual depends foundationally. So how well the user engages with the represented meaning-content is detemcined by all four of these aspects. Expanding on the EwT/HCI chapter (III, §3.1), when the user is receiving output from the computer, i.e. interpreting it: » The psychic aspect of this is our seeing the screen shapes and colours on screen, hearing the sounds from the speakers, and so on which are intended to form symbols that carry meaning. This can be hindered by, for example, colour blindness, deafness, or by distraction, and so on. » The analytic aspect of this is distinguishing those shapes, colours, sounds, etc. that carry information from the rest, which are all about us, and understanding what basic pieces of data they are intended to convey. This can be hindered in two ways: » It can be hindered if the shape or sound is not easily distinguished from its background, or from other shapes or sounds. For example two words might be run together, or two shapes might overlap each other. » If it is not clear what kind of information the shape or sound is intended to convey. For example consider a vertical oval on its own 'O' or '0' - does it afford a letter, a number, or something else such as a bullet point? » The formative aspect of this is the structuring and processing of these basic pieces of data: letters or phonemes into words into sentences, etc. graphic shapes into complexes into diagrams. This can be hindered if the user cannot see how all the various shapes or sounds should work together to make something meaningful. In text, this is why punctuation is important. In graphics, spatial alignment and proximity is often important - for example, consider a table of numbers rendered in two ways. First, we have the data separated by commas: Nuclear: 6.0, 6.2, 7.0, 7.5, 8.5 Onshore Wind: 8.0, 8.5, 9.0, 10.0, 10.2 CCGT: 6.0, 7.5, 8.0, 9, 10.5 CCGT with PC CCS: 6.6, 7.0, 7.5, 10.0, 11, 15, 16 Biomass: 6.5, 7.0, 8.0, 9.5, 10.5, 11.5 Offshore Wind: 15, 16, 18, 19, 20.5 Tidal: 16, 19, 20, 24, 39 Coal with PC CCS: 10, 12, 13, 13.5, 14, 14.5, 15.5 Gas 20%: 9.5, 10.5, 11.5, 13, 14, 15, 17, 17.5, 18 Now, if we align them spatially: Nuclear: 6.0 6.2 7.0 7.5 8.5 Onshore Wind: 8.0 8.5 9.0 10.0 10.2 CCGT: 6.0 7.5 8.0 9 10.5 CCGT with PC CCS: 6.6 7.0 7.5 10.0 11 15 16 Biomass: 6.5 7.0 8.0 9.5 10.5 11.5 Offshore Wind: 15 16 18 19 20.5 Tidal: 16 19 20 24 39 Coal with PC CCS: 10 12 13 13.5 14 14.5 15.5 Gas 20%: 9.5 10.5 11.5 13 14 15 17 17.5 18 The two renderings contain exactly the same information, but one is easier to decipher than the other because it as been structured more intelligently (formative functioning). (Intentionally I do not yet tell you what the numbers mean, because that is lingual functioning!) » The lingual aspect of this is understanding what these mean and were intended to convey to us. For example, now I can reveal that the figures are total life-cycle costs for different means of generating electricity. Such lingual understanding can be hindered by not understanding what the recognised symbols stand for (think of a map without a key, or text with words you don't understand). However well-structured and distinct it might be, if you don't know what each type of symbol is intended to signify, then you cannot understand. Now, Fig. 1 was relatively easy to understand: company C makes most profit. But not fully: does the 400 mean 400, 400,000, 400 crore, or 400 million, and in what currency is it? There is a slight lingual problem there. Fig. 2 is difficult to understand because of the analytic problem that we are misled into thinking that length of bar implies a quantitative amount rather than a relationship. At the lingual level, however, it is relatively easy to understand. Fig. 3 is relatively easy to understand at both analytic and lingual levels. IX-2.3 User Interface 'Objects' A user interface 'object' is a device that enables the user to interact with information. At least four aspects are important: » hardware and activity of organs of the human being » bits and signals, and human psychic mental functioning » the type of information it allows the user to handle, and human cognitive / analytical functioning. » the structure of the object in temcs of smaller objects, and the processing they carry out, and human goals. Affordance refers to the link between the psychic aspect and the analytical and formative. What follows is discussion of a number of affordances, for both output and input: » §2.3: the types of psychic phenomena that are currently available to us via computer user interfaces, » §2.4: a number of types of information (the analytic aspect) » §2.5: what is good and poor affordance between these » §2.6: a number of types of structure (formative aspect) » §2.7: good and poor affordance between formative and psychic aspect » §2.8: affordance of input. IX-2.3 Types of Psychic Ways By Which We Can Express Information In the EwT/HCI chapter was listed the various kinds of psychic phenomena that can occur in a user interface to carry information. IX-2.4 What the visual channel offers # Purely sensory; to do with sight, colour: » hue (red, brown, green, etc.) » saturation (how much white is mixed with the colour, e.g. pink is red with some white) » brightness (also called value) » texture (patterns of colour, such as grids) » colour shading » background and overall colour scheme » what colours are available (called the 'palette') # Sensory aspect serving the spatial aspect: » shapes of any type, some of which we might recognise (such as the shapes of the letters of alphabet, i.e. a font) » size of shapes » length of shapes » position of shapes » distance between shapes » orientation of shapes » angle subtended by shapes, especially lines » spatial alignment of shapes, e.g. vertically above each other » shapes touching or connecting with each other » spatial patterns like surrounding or overlapping » perspective (smaller shapes seeming more distant) » background » multi-colour scenes like photographic images # Sensory aspect serving the kinematic aspect: » Movement of objects across the screen » Speed » Direction » Relative motion » Changes in size » Flowing motion, field motion » Colour changes, flashings » Morphing from one shape to another IX-2.5 What the aural channel offers The aural channel works by setting up waveforms in the computer's memory, which are sent to the loudspeakers by means of specially designed electronics. Each sound starts, is sustained for a time, then fades away. In musical instruments the start is called the 'attack', and the fading, 'decay. » Sounds in general, of which we have the following qualities: » Volume of sound » Pitch of sound (high, low; which note is played in music) » Qualify of sound, such as whether pure or fuzzy; vibrato » Rates of attach (build up) and decay (fading) » For music, or any combinations of sounds in sequence, we have in addition to the above: » Chords, discord » Melody » Rhythm » Tempo » For speech, which is a sequence of phonemes (the basic sounds of speech) we have the following qualities (see below): » accents » gender » emphasis » rising and falling of the pitch and volume » rhymes IX-2.6 What the haptic channel offers The haptic channel works by controlling a mechanical activator in contact with the skin. It offers: » The feeling of resistance, e.g. as user tries to move joystick » An impulse (kick) given by computer » Vibrations of various types » 'Texture' of surface (e.g. sandpaper, cloth, shiny metal) » A feel of pressure, springiness, softness, etc. IX-2.7 Types of basic information Recall the types of basic information from EMC: » Items. » Attributes (of items, or perhaps state of whole scene). » Relationships. » Quantitative values. » Qualitative values / Enumerated type. » Spatial knowledge. » Discrete events. » Continuous processes. Each of these needs to be expressed by psychical phenomena. IX-2.8 Affordance: How to Express Each Type The question is: which psychic-aspect phenomena should or can we employ to express these various types of information? Gibson [1977] discovered that certain visual phenomena seem to 'afford' certain types of meaning better than others. Greeno [1994] applied his ideas to user interfaces. For example, the length of a line or bar 'affords' quantitative value - hence slider widgets - but it is usually imprecise quantitative value. For expressing precise quantitative value, digits are better. Qualitative value can be expressed better by colour hue - think of traffic lights: stop, ready, go expressed by red, amber, green. In the lecture an example might be given of a poor affordance, taken from Norman (1990). It shows bar chart used to link car makers with their country of origin. Though it does indeed provide the necessary information, it is not so natural as e.g. using simple dots in a matrix, and requires more effort on our part to interpret it. Length of bar affords quantitative value, not relationship, which is a different type of symbolic meaning. (Actually in this case the we have a second visual form that does 'afford' relationships, namely the matrix. Therefore the case is not as bad as it could be.) (Is such affordance due merely to our being used to using bar charts for numeric values rather than relationships? No. While cultural factors have some bearing, there is a foundation of affordance that is deeper.) Here are a few common affordances: Icon present item / entity (e.g. box and arrows diagrams) Shape item / entity type (e.g. rectangles for data, diamonds for actions) Linking line relationship (e.g. box+arrows diagram) Sound occurs event Music process Animation process Length quantitative value (e.g. bar chart) Size quantitative value Colour hue qualitative value / enumerated type, usually representing entity type (e.g. traffic lights) Visual texture (e.g. dots) enumerated type (qualitative value) Brightness quantitative value (e.g. danger level) Saturation quantitative value Colour spreading quantitative value range (e.g. map contours) Relative position quantitative value (e.g. slider gadget) Angle of line quantitative value (e.g. pie chart, speedo) 3D look entity (item) separated from background (e.g. icon) Spatial alignment relationship Visual similarity similarity of attribute; set membership Flashing qualitative value: 'important' Animation speed quantitative value Tempo of music quantitative value e.g. of danger level Volume of sound quantitative value Pitch of sound quantitative value Texture of sound enumerated type digits quantitative value ... and so on. Many pertain in paper graphics as well as on computer screens. For good examples, see books on graphic design, especially Tufte 'Envisioning Information'. {*** Look at the icons and widget pictures and assess the affordance of each. ***} Here is the above list reordered by type of data, giving a list of possible ways of expressing it with the psychic aspect: item / entity: Icon present (e.g. box in diagram), 3D look item / entity type: Shape (e.g. rectangles for data, diamonds for actions) relationship: Linking line (e.g. box+arrows diagram), Spatial alignment event: Sound occurs (beep), flash process: Animation, Music qualitative value: Colour hue (e.g. traffic lights), Visual texture (e.g. dots), Texture of sound, Flashing similarity of attribute: Visual similarity quantitative value: Digits, Length, Brightness, Angle of line, Relative position, Tempo of music, Colour spreading, Animation speed, Pitch of sound, Degree of colour saturation, Size of shape, Volume of sound {*** Think: Which types of data are missing from that list? There is at least one. Then think: how would I best express that (a) visually (b) by sound, if at all? ***} IX-2.9 Structure of Pieces of Data What we see (or here or feel) is not just discrete pieces of data, but information in relationship to each other, with a structure. There are various kinds of structure and each has better and worse ways of expressing it. The information itself is structured; it is not just a disparate collection of bits of data, but the data itself is linked together. Items can be linked together in several ways: in a collection or set, in a linear list, in an hierarchy, or in a network. The user interface is designed to show structure of data, and each of these structures is best shown in particular ways. For example: To show a set or collection of items: » On your Desktop, you find a number of icons; these are icons that you intend to use often or want convenient access to (both formative concepts). » On Apple Mac and Amiga when you open a directory you are presented with a rectangle in which are yet more icons; the boundary of the rectangle serves to show 'set' or 'collection'. » Another way to show a set or collection is to place them in a group spatially separate from others. To show a linear order or sequence: » A table often shows linear order down its rows, each row being a record that is meant to be after the previous one and before the next (e.g. members of a family in age order, e.g. list of files in alphabetical order). » Bullet list in text shows linear sequence. To show hierarchical (tree structure) relationship (one-to-many): » The directory-and-file list shows the structure of files and directories. » A tree diagram shows hierarchical relationship. To show network relationships (many-to-many): » A box and arrows diagram shows a network. » On web pages hyperlinks show how one page is structured in relation to another. This is a kind of affordance, in which spatial aspect of layout expresses formative aspect of structure. IX-2.10 Expressing Updating and Manipulating Information Not only output but also input has affordance. That is, different gestures we make with our fingers, hands etc., are good for different kings of information. The user wants to do something at the computer: to send a command, to modify or enter data, to interact with what they see on screen or hear through speakers, and so on. Under the formative aspect of user input we consider what the user might want to do, and how to design the UI to make it easiest to do it. There are many ways to do many different things - which contributes to the richness of the user interface, and also its ability to confuse. Here we link a motor action (psychic aspect) with formative intention of the user. Again we have the idea of affordance: Some psychic motor actions are better at expressing certain types of formative intention than others. When the UI is easy and natural to use, with good affordance, we call it a Proximal User Interface (PUI) because it is 'close to' the user. IX-2.11 Distal and proximal When we first use an artifact for some purpose, at first we are aware of it, thinking about how to use it right, but as we become used to it, it we begin to forget about it and take it for granted, and its use becomes second-nature to us. The philosopher Michael Polanyi [1967] used the temcs 'distal' (at a psychological distance from us) for when we are unfamiliar with it but and 'proximal' (in our psychological proximity) when we are used to it. In a proximal relationship with a tool our attention is not on it but rather on the task for which we are using it, but in a distal relationship, some of our attention is distracted to attend to the tool as such. For example, you use a pen to write, but hardly give a thought to the pen, and if you drive a car you hardly give a thought to the steering wheel. Unless they break! Then you give a lot of thought to the artifact, especially the steering wheel! It's the same with our interaction with the computer. It can be either distal or proximal. It is distal at first, when we are learning about it, because we need to think about it. But, as we learn, it becomes proximal to us, and we can give all our attention to our task. For example, using a word processor for writing, you just write and forget the software. For example, using your mobile phone to speak or text someone, you hardly think about the artifact you hold in your hand, giving almost all your attention to the meaning-content of what is coming through its speaker or its screen. They are proximal to us, once we have learned. Unless something goes wrong, in which case, we interrupt our thinking about the task to attend to what is wrong. It becomes distal to us again during that period. In the 1970s and 1980s the difference between distal and proximal was not recognised, and the EwT/HCI relationship was assumed to be distal. It was often understood metaphorically as dialogue between two agents (human and computer). For example, nearly one third of Downton [1991] is devoted to 'Human-computer dialog design'. But this distal relationship is problematic; Norman [1990] remarked: "The real problem with the interface is that it is an interface. Interfaces get in the way. I don't want to focus my energies on an interface. I want to focus on the job." Ben Shneidemcan [1982] pioneered 'direct manipulation', which enabled the 'direct engagement' that Brenda Laurel [1986] called for. Basden, Brown, Tetlow and Hibberd [1996], introduced the temc and concept of Proximal User Interface (PUI). A PUI is one that is so easy and natural to use that it becomes second-nature very quickly. Here are some examples of PUIs: » Word processor, in which you simply type your text without thinking about the WP, until you want to do something special. In text-oriented applications, keyboard short cuts are more proximal than having to go to the mouse and move up to the toolbar or menus. » Computer game, in which all the activity is via a joystick or just a few keys, and the activity is quickly learned; if this were not so, the player would soon be killed or otherwise lose the game! Computer games designers are excellent at PUIs - because they had to be! » Paint program, in which you want to shade a colour to some other shade, and do so simply by wiping the mouse cursor over it. » Mobile phone, in which you scroll down the menus by pressing keys repeatedly without thinking. » Mind-mapping package that allows us to draw boxes (for concepts) and arrows (to link the concepts together) simply by dragging the mouse, and without any need to attend to menus or toolbars - so our thinking is not interrupted. Basden and Hibberd [1996] describe such a package, which allowed a user to create a very complex and sophisticated knowledge base to write construction contracts. By contrast, some UIs take a long time (if ever!) to become proximal, and so their users are always having to give half their mental effort to driving the UI, rather than focusing on the job. Typical examples are: » Early computer games on the Microsoft Windows, which made too much use of the mouse and menus. » Word processors in which you often had to grab the mouse and find the right menu in order to do what you wanted. » Banner marks entry system, which is via a web-based UI, in which you have to enter marks of one student at a time, scroll down to hit 'OK', then you are presented with a blank screen saying 'Mark altered' and you have to hit OK, then you are taken back to the wrong place and have to scroll around to find where you were in the list. Growl!! Basden, Brown, Tetlow and Hibberd [1996] worked out principles of PUI for mind mapping software: » Principle of direct semantics: Appropriate movements for the type of information being dealt with » Principles of large easels: (A easel is what you draw on.) The whole screen should be easily visible, and scrolling should not require attention to a scrollbar but should be automatic » Principle of visual cues: When someone draws something, they retain a memory of how it looks, so do not destroy these visual cues by e.g. automatic layout. » The Clutter principle: Real-life knowledge is messy and unpredictable, and as you draw your map it will become cluttered; make it easy for the user to de-clutter it by moving things aside. » The Principle of the Free Hand: Remember that user has a free hand, which could be made use of, to modify operations. » The Principle of Tentative Action: Allow the user to make small actions such as setting down bits of information 'while they think of it' for future attention. » Principle of Graded Effort: Common user actions deserve to be more proximal, while others deserve to be more distal. » The Irreversibility Principle (Danger Principle): Dangerous operations should be more distal, e.g. deleting something, or deleting all things of a certain type. Ben Shneidemcan was once surprised (as the author heard him tell) when one of his students, who was using a text editor, contended "With the cursor over a word, I hit 'dw' to delete it; what could be more direct than that?" Shneidemcan had until then assumed that direct manipulation requires the mouse. But in fact it can be undertaken by a keyboard. For a PUI the designer must detemcine: » what are the operations that the user wishes to undertake on each type of information » what are the most natural gestures for each of these operations » and how to grade the effort for each of these gestures. (See paper on Proximal User Interface for this.) We give a few examples in this section, and more below in the next section. IX-2.12 Types of Actions On Information First, we must have a clear picture of what types of operation can be applied to which types of information. Then for each we will give some examples of good psychic gestures that are natural for that type of operation. Items (objects, entities, etc.). Items can be created and deleted. They can be 'moved' in temcs of their 'position' in relationship to other items, such as moving to head of queue (note that this is different from psychic 'movement', that is to another position on the screen). Items can be split, merged and cloned. They can be related to each other. They can also be identified; note this operation does not alter the item. When you have a set of items (e.g. the whole Model) you can sort them, search for them. You can also show them (express them in a View). You can add attributes to items, remove attributes from them. You can change the type of an item. Finally, items can be sent messages or told to take actions; in this way they are the traditional OO object. For each of these operations (and others not mentioned here) the Controller needs to offer the user the ability to do each. Thus the UI designer must detemcine what gestures should be used for each operation. A useful guide to design is the Principles of Proximal User Interface. For example: » Create a new item: A frequent operation, so make it highly proximal (low cognitive effort), e.g. a simple singld mouse drag. » Delete an item: A common operation but can be dangerous, because deleting an item requires destruction of much information, including details of the item, details about each of its attributes and all the relationships it has. So make this a more distal operation, less easy to achieve. e.g. click to bring up 'Are you sure?' panel. Relationships. Can be created, deleted, redirected, reshaped (at psychic), have their weights changed, etc. For example: » Relate two items: A frequent operation, not dangerous, so implement it using a single, simple mouse drag. » Redirect a link: A common operation in ill structured domains, and not very dangerous. Make it reasonably proximal, e.g. a simple mouse drag in which a qualifier key is held down. Attributes of items, and global. You can answer an attribute, or clear it. You can override it. Attributes of items can be treated as little items in a list, namely the list of attributes of the item. Quantitative values. Numeric values can be increased and decreased, by addition or multiplication. They can be negated. They can be randomized. Several values can be combined together, e.g. by addition, but also by concatenation. They can have any complex function applied to them (e.g. sin, log, power). They can be compared, for relative magnitude. For example: » Alter quantitative value without need for great precision: Use a simple mouse drag on a slider. Or mouse-wheel. » Alter quantitative value with precision: Use (numeric) keyboard to type in precise digits. Or allow user to click with mouse over top and bottom of each digit to increase or decrease it. Qualitative values. Qualitative values possess no ordering, so they cannot be increased, added to, negated or compared for magnitude. They can however be compared for equality. Several values can often be combined together, often in diverse ways; for instance combine two pieces either one after the other or to be played at the same time. Spatial things. Spatial things can be moved, rotated, scaled, stretched, bent, overlapped, buffered, etc. They can be compared, though comparison is much more tricky than with values. » Most spatial manipulations are best undertaken with a mouse- drag. Events. Events can be started. They can be applied (to an item, a value, etc.). » Events are best activated by hitting a key. » But they are also often activated by moving mouse over what appears to be a three-dimensional button on the screen and clicking the mouse button there - but this is not quite so convenient because of the need to move the mouse to target first. Processes. Processes can be started, stopped, paused, interrupted, and also altered while in progress. They can be traced (e.g. the running of a computer program). » Processes can be controlled by moving the mouse. The most direct is that when the mouse moves the process is happening, and when mouse stops the process stops. » Alternatively, the process can be started by hitting a key, and then moving mouse to control its speed etc. » Very good for controlling processes is the joystick (e.g. in a driving game). These are not complete lists, though they are probably as complete as you will find almost anywhere. However they give us the basis for understanding what the Controller should do. {*** Think about the actions you take on your mobile phone to achieve things - e.g. repeat keying to enter letters, wiping to move up and down menus, etc. Make a complete list of what actions you take, and decide what formative or analytic thing you are trying to achieve with each (analytic = entering data, formative = structuring or achieving something). ***} IX-3. THE EMC-HLC LINK: INFORMATION RICHNESS AND INFORMATION FULFILMENT Just as EwT/HCI enables EMC, so EMC enables HLC. To live with computers and ICT, to gain benefit (or harm) therefrom, requires that we engage with the meaning that is represented in the computer. In the example of the nurses' database, the user found (information representing) a drug given to the patient that should not be given (engaging with what the information means), so went to check with the physician (human living with computers). It is exactly because the user engages with the meaning, knowing and understanding what the represented information means, that they are able to live with the information system or computer. "What the represented information means" - what do we mean by that? In the EMC chapter, this was usually assumed to be explicit, meaning, deliberately entered; for example that a certain patient is on a certain drug for a certain illness. So, at the appropriate time, the nurses would give that patient that drug (effect of explicit information on HLC). But it could also be implicit meaning, or cultural connotation, for example, it is only because the nurse is steeped in that particular medical culture and has wider knowledge of the side effects of drugs that s/he knew there was a problem with that drug, and hence took action to check with the physician (effect of implicit meaning on HLC). Implicit meaning is also known at tacit knowledge and lifeworld (shared background understanding). There has been very little written about this link between EMC and HLC. However two notions have surfaced: » Information richness [Daft & Lengel 1984] » Information fulfilment [Burke 2006] Information richness is defined by Daft and Lengel as "the ability of information to change understanding within a time interval". They focus on how different types of medium allow greater or lesser richness of communication between people. For example, face-to- face is richest, while one-way communication 'lean'. A medium is rich if it can clarify ambiguous issues and promote understanding even when source and recipient have different frames of reference, and do so in a timely manner. So Daft & Lengel moved their interest away from information richness to media richness, and believe that a rich medium » allows immediate feedback » has a number of parallel channels and cues » allows variety of language » encourages intent to be focused on the recipient rather than the source. Unfortunately, the notion of information richness was not developed in a way that helps EMC. Better is Maria Burke's [2006] notion of information fulfilment. She defines it as "achievement of all information needs". She traces its root back to the 1870s when it referred to fulfilment of a commercial order. Burke makes clear the link between EMC and HLC: "The aim of an information system is to ensure that the end user is able to function effectively within the organisation - and able to access all the necessary information in order to complete a task." The notion of information fulfilment needs further elaboration. It may be that Dooyeweerd's aspects can help, in that information about different spheres of meaning (aspects) might achieve the needs of the user in different ways. But this has yet to be investigated. IX-4. THE HLC-EwT/HCI LINK: ERRORS Though the main link from EwT/HCI to HLC is via EMC, there is also a direct link, which becomes noticeable when errors occur in EwT/HCI. This link has not been much researched, but here are a few examples: » Your hard disk crashes, losing all your files. You then have to spend hours and hours recovering as much as you can. That is a big impact on your life: 'living with computers' becomes a disaster! » You click the wrong button - the delete button - without realising it, because the layout of the UI is poorly designed. So you lose a valuable file, without realising it, and when you try to find it later you cannot, and you spend hours searching for it all over your hard disks and USB sticks! That's an impact of EwT/HCI on HLC! » IX-5. EwT/HCI-EMC-HLC: COGNITIVE DIMENSIONS Thomas Green has been particularly interested in measures and models that help UI designers in actual design. Green and Petre [1990] came up with a suggestion that there are a number of 'cognitive dimensions' to any information artifact, and that these have various uses. They range over all of EwT/HCI, EMC and HLC. Viscosity: The difficulty in, or cost of, making small changes. Hidden dependencies: A dependency is not visible, and so users are messed about when they try to do something. The main example discussed is pointers, i.e. one-way links in which the inverse link is notionally there but not explicitly either shown or supported. Premature commitment: User is forced into making decisions or commitments before all information is available. Abstraction barrier: Measure: the minimum number of new abstractions the user must understand before user can use system. [What about concepts to understand? Better to widen the cog dim to take these into account?] Abstraction hungry: User must create loads of abstractions before beginning to use the system. Secondary Notation: Extra information carried by means other than the official syntax, and the ease with which user can create and keep such notations. e.g. notes in the margin of books, comments in programs, indentation of program code, grouping of control knobs ('redundant recoding'), annotation on diagrams ('escape from notation') [Also comments in programs?] e.g. gaps in phone numbers. e.g. different fonts used in paper diaries. (Secondary notation is, of course, very similar to Visual Cues of Proximal UI.) Visibility and Juxtaposibility: Ability to: view components easily (visibility), compare components (juxt). Closeness of mapping: Close mapping: what the user sees is directly what is represented internally. Minimum number of new concepts to learn [is this similar to abstraction barrier?]. Note the similarity of this dimension to the Principle of Appropriateness in Proximal UI. Consistency: Similar semantics are expressed in similar syntactic forms. e.g. 'OK' button always on same side. Diffuseness: Verbosity of language. COBOL is diffuse. Forth is terse. Error-proneness: Notation invites mistakes. By: » Poor discrimination. Esp. visual. E.g. dot and comma in Forth means different things. [= And == in C] » Inadequate syntax checking. E.g. Prolog has no declarations, so mistyping of name gives new variable. » Bad dialogue design. E.g. using 'enter' except on one case. » Memory overload. Caused by premature commitment. Hard mental operations: High demand on cognitive resources. Threading a maze, e.g. finding a file in a large directory tree. Progressive evaluation: Work to date can be checked at any time. E.g. Spreadsheet recomputation is easy. Provisionality: Degree of commitment to actions or marks. E.g. pencil used by architects can be hard line or fuzzy line 'something like this somewhere around here'. Role expressiveness: The purpose of a component (or an action or a symbol) is readily inferred. This set of concepts is very useful, but it is a bit ad-hoc, according to the originators, having been derived from observations and experience. It needs a sounder foundation. Maria Kutar and I are working on a foundation based on Dooyeweerd. Copyright (c) Andrew Basden & Janice Whatley. 25 November 2009, 28 January 2010, 20 September 2010, 14 September 2012.