CHAPTER IV. ERM - ENGAGING WITH REPRESENTED MEANINGFUL INFORMATION It is of little value having a superb user interface if the content is meaningless or irrelevant. Whereas in HCI the relationship the human has with the computer is with the symbols of the user interface as such, the relationship the user has with the computer in ERM is with what they represent. 1. INTRODUCTION In this chapter we look at the issue of meaning-content that is presented via the UI or HCI to the user and received from the user and represented within the computer. We examine the user's engagement with represented meaning (ERM). Several big questions of human use of computers are addressed here: » How do we judge quality of information content? » How do we differentiate virtual reality from 'real' reality? What laws apply to each? » Why can false information be so plausible? (e.g. fake identities in social networking, false emails offering us money) As you read this chapter, bear in mind: » what the nurse in chapter 1 found out about the patient from the database » your fighting the dragon in the computer game, again in chapter 1 » the *meaning-content* (not the HCI) of any website you might have read » your use of social networking sites like Facebook, because here you engage very closely with the meaning that is represented on your page, which comes from your friends » your engagement with virtual reality (such as the Second Life site) » the *meaning-content* of any email or blog you read. It is all about meaning-content that is represented via the HCI, but we are not concerned with the HCI itself (that is how the meaning- content comes to you). Nor are we concerned with what impact the content has on your life and work; that is HLC. In the Human Experience chapter, we summarised aspects of meaning-content of a computer game. But that is only one of three ways of looking at aspects of represented meaningful content. After examining ERM itself in more detail, we will look at each of the three: » using aspects to classify types of software (section 3), » using aspects to assess the diversity and completeness of information content, such as a computer game or database (section 4), » using aspects to assess the overall quality of information content (section 5). Thus we use aspects here in these three different ways. We use aspects mainly to help us ensure that all issues are covered in each of these three. 2. WHAT IS ERM? You are reading a book, such as a thriller or novel. You get so involved with the story that you don't want to put the book down. You find yourself wanting the heroine to succeed, and sad when she fails or dies. This is ERM, engagement with represented meaning, engagement with the meaning-content that is represented in the text you are reading. It is not just computers that have ERM. What is said in this chapter, could almost equally apply to books. And to films, television, spoken conversations, and any other lingual medium. What this means, is that much of what has been written or said on good authorship is relevant to ERM of computers. It might have to be adapted to the different medium, of course, but if you really want to understand ERM, go to such works - because there is not very much written on it in the HCI textbooks. The main difference between books and computers lies in the fact that in computers you can have an impact on the content, whereas in books you cannot. Content in databases can be modified, content in games (dragons!) can be killed, and so on. But when you are searching a website for information, you could do almost as well with a book, because you are not modifying the information. The represented meaning with which the user engages is mediated by symbols that make up the lingual aspect of the HCI. Most obviously, these symbols are those which are presented on screen. But it is little more complicated than that. First, of all symbols on screen, some have little to do with the main meaning-content, but are to do with the software being used (e.g. the toolbar icons and menus) or with the operating system (icons on desktop). When engaging with the represented meaning-content of an application we tend to forget all about the surrounding menus and toolbars except when we want to do something. So, in this chapter we ignore all those extraneous icons and menus, except for when we are focusing on what they themselves refer to or represent. Let us focus on those symbols that do represent the meaning- content of the application (database, computer game, social networking site, mobile phone, etc.). To what do the symbols refer? We can see immediately that there are three possibilities: » Symbols ---> things meaningful to us in real world (e.g. a patient or a type of plant) » Symbols ---> things in our imagination: virtual reality (e.g. a game) » Symbols ---> false things (e.g. false identity). In principle, we cannot tell which our symbols refer to from within ERM. They are differentiated, however, by HLC, which we cover in another chapter. In HLC: » Things are meaningful to us in the real world for a whole variety of aspects. » Things in our imagination are often there for aesthetic purposes in HLC, and laws can be played with. » False things often impact on the juridical (legal) or ethical aspect of our HLC. The intention to deceive is a matter of attitude in real life, and this is a moral HLC matter. The idea "something they are not" refers to the state in HLC, rather than ERM. It is also why faults in a database can go undetected. However, there can often be clues within the represented meaningful content itself which it is. For example, in virtual reality the laws that govern our real lives are often modified; for example when you die in virtual reality you can often be resurrected, for example you can teleport, for example you can use magic at will, for example your character is measured by only six main stats: strength, intelligence, wisdom, constitution, charisma, dexterity. All this tells you it is not real life, and probably virtual reality. But false meaning often tries to deceive, and might be more difficult to detect. 2.1 Other Symbols that Mediate Meaning-Content Most meaning-content is mediated via symbols presented in the user interface (screen and speakers). But ERM is not restricted to this, because some comes to us by other means: » The way things behave. For example, the way the dragon moves is part of the meaning-content, and you would be wise to take account of it, else you might die! Sometimes the sequence in which things are presented to you by a database or knowledge base can be significant in a system that gives you the most important information first (e.g. order on search engine results). Sometimes false information 'behaves' in a way that feels not quite right. » Some documentation or help pages. While a lot of documentation is about the HCI, some of it will give you the background to game's scenario, such as why you are in the dungeon and fighting the dragon and what your quest is. The documentation or help pages can also give explanation of things you encounter in the game. » Via others. Often meaningful content information comes via other people. Other people can help you play a computer game, perhaps giving clues to overcome tricky bits. Other people will sometimes alert you to what kinds of information is false; for example, emails that request your help to handle a large sum of money, or emails from banks asking for details. It helps to know that responsible banks would never ask for details by email. So, as we consider ERM in more detail, bear all these in mind, and possibly more. Probably most of what we discuss will be that which is presented via symbols on screen, but some of it might not be. 3. TYPE OF APPLICATION SOFTWARE There are lots of types of applications of ICT, lots of types of software - calculators, word processors, web browsers, computer aided design packages, computer games, computer music, software that helps you write a will or a contract, and so on. How do we sort them all out? One way of doing this is by reference to aspects of the kinds of information content they most process. This is because Dooyeweerd's aspects are not only categories, but are spheres of meaning, or ways in which things can be meaningful in everyday life. We can ask ourselves "Which aspect best characterizes the purpose of this software or IS?" (Dooyeweerd calls such an aspect the qualifying aspect of a thing.) In the case of a calculator it is the quantitative, in the case of a word processor, the lingual, in the case of a game, the aesthetic, and so on. Table 1 gives examples from most of the range of aspects. It is primarily this 'qualifying' aspect (see chapter II) that determines what meaning-content or facilities are relevant in an IS. Some IS, however, are designed for multiple purposes, and so might have multiple qualifyiing aspects. So this means more diverse content or types of facility. Table 1. Qualifying aspectual of extant software In fact, in most IS, the aspects represented in the meaning- content will be many more than just that of the qualifying aspect(s). This is especially the case for virtual reality systems and computer games, as we discuss below. Even for other types of software, if close attention is given to all aspects in this way then the IS will be flexible enough to support changes in use. This happened in Elsie, such that its qualifying aspect changed. It was originally to set a budget (economic) but this changed when it began to be used, to the analytic function of clarifying requirements. This is not unlike the case of antique shawls that become wall hangings and castles that become tourist attractions, which the philosopher Dooyeweerd discussed [1984,III,p.143]. {*** If you are interested in taking that further, read Dooyeweerd's book, which is a reference work in the library - but beware, he writes as a philosopher so some of his writing can be rather detailed! ***} Thus the way to obtain flexibility to be able to cope with unintended uses of an IS is to incorporate a wide range of aspects in the meaning-content of the IS. 4. USING ASPECTS TO ASSESS THE COMPLETENESS OR REALISM OF INFORMATION CONTENT Whatever aspect is the main purpose of a piece of software, many types of software also hold information about other aspects. In generic software like databases or computer games the range of aspects held is often very important. In chapter II when we summarised the aspects represented in a computer game as follows, we were assessing whether the game embraced the whole range of what is meaningful to us: » Quantitative - Character has certain amounts and numbers of things. » Spatial - Can character orientate themselves? » Kinematic - How easily can character move around? » Physical - Are solid things solid? Does force push or hit things? » Biotic (Organic) - Eating, drinking, resting, etc.? » Psychic - Does the character have realistic feelings? Can they hear or see in the game? » Analytic - Can the character identify things they come across? » Formative - Does character or player have to make plans? Construct objects? » Lingual - Can character or player make notes, or correspond with others? Are there signs or notes to read? » Social - Does character operate alone or in group? Friends or enemies? » Economic - Does character have to be careful to obtain and conserve various resources? » Aesthetic - Is playing fun? Surprises? » Juridical - What are the laws within the game? What is due to each type of character? » Ethical - If the character is generous or self-giving, does this improve the game or its atmosphere? » Faith - What is the character about in the game? Is loyalty and commitment rewarded? Is there realistic representation of religion? This kind of analysis can also be used to assess the completeness and coverage of the content of any computer system, such as a patient database or a website. However, we will expand this below by means of a details look at a playing of the public domain game, ZAngband, in which we fight a dragon. Appendix 3 is a printout of the character information obtained during the fight with the dragon. In ZAngband we find nearly all the aspects represented, as shown in Table 2. In ZAngband, a character controlled by the user explores a dungeon of many levels and has a quest ultimately to kill the Serpent of Chaos. Though the user is male and human, the character is a female High Elf, who has the role of 'Chaos Warrior'. Her visual personal details (see Appendix 3) are: You are one of several children of a Noldor Warrior. You have light grey eyes, straight black hair, and a fair complexion. Complete details of Mindorf are in Appendix 3, to which you should refer as you read this. Though this is in fact a simple dump of the character by the software, and thus contains much information not needed here, certain pieces of information are should be looked at. Mindorf is fighting a type of dragon, a Great Hell Wyrm, for which you will see some of the fight in the section '[Message Log (last 42 messages)]' at the end of Appendix 3. When it refers to The Great hell wyrm shudders. You unstack your staff. You have 2 charges remaining. it means that Mindorf has used a Staff of Power, a magic device which does immense damage to the enemy. Now, let us consider the aspects of the game in more detail, to see how the representation of each adds to the user's experience when playing the game. If is likely that the ZAngband game will be shown in class. A wide margin is left for you to make notes of this, or else to make notes of another piece of software (e.g. a website or database) that you are assessing. Quantitative aspect: Amount and number of things in the game, such as number of enemies killed, number of turns. This aspect helps the user keep track of the game. Spatial aspect: This is germane to the whole game, because it is a game of exploration. Without a spatial aspect, this particular game would just not exist. The spatial aspect is exhibited in the layout of the game, with its rooms and tunnels, the proximity of items or enemies are in relation to Mindorf, and such things as whether a protective wall lies between Mindorf and the enemy. Kinematic aspect: Movement around the rooms and tunnels, and to escape or hunt or fight enemies, is also germane to the game. The ability to enhance one's speed, so that one moves faster than the enemy, is very useful; on the other hand, there are some enemies which can throw a spell to reduce one's speed. Mindorf has a Ring of Speed, Boots of Speed, and a mutation of an extra pair of legs, all of which increase her speedd. If she uses a Staff of Speed, her speed increases by yet another 10, which is useful when facing particularly dangerous opponents like Great Hell Wyrms. Physical aspect: Mindorf cannot move through the rock walls of rooms and tunnels, but some 'undead' things can move anywhere (e.g. ghosts, wraiths). This, however, plays only a small role in making the game interesting. Organic (biotic) aspect: Mindorf needs to find food to eat to stay alive; she must remain healthy. She will receive wounds during battles which, if too severe, kill her. She can also be poisoned by various enemies or by quaffing a potion of poison (she might not realise what it is). Mindorf's health is measures in 'Hit Points' and currently stands at 572 out of a maximum of 728. The characteristic of Constitution, which stands at 18/190, is a measure of how healthy and robust Mindorf is, and how quickly she recovers from wounds. Various enemies and stepping on various traps can inflict her with various diseases. Also, a character can have mutations; the list of Mutations of Mindorf (see Appendix 3) makes interesting reading - such as horns and an extra pair of legs, an extra pair of eyes and the ability to shoot laser beams! Psychic aspect: Mindorf can see and hear, and thus detect enemies and know where objects are. Except when it is dark and she has no light source. However, she can see in the dark up to 40' away, because of Infravision. One particular danger is blindness. She can become blind by an enemy casting a spell on her, by quaffed a potion of blindness (she might not know what the potion is), or stepped on a trap that makes her blind. When she is blind, she is at the mercy of her enemies. Not as bad as blindness is confusion. Various enemies can cast a spell on her of confusion, which means that if she tries to fight them her blows go astray. When blind or confused she cannot read any scrolls or cast any magic spells (such as those that might help attack the enemy). Sleep and paralysis, which can be cast by enemies, are dangers worse than blindness, because she cannot move. All these sensory-motor ailments are cured with rest - but she cannot rest unless completely alone. Analytic aspect: The analytic aspect is usually very important in games, for identifying things. Identifying objects is particularly important, and there are various levels of this: seeing things, reading a scroll of identify, which reveals more about them such as differentiating a good from a poor sword), and reading a scroll of '*identify*', which reveals any magic properties that weapons and armour and clothing might have, such as protection from fire, cold, poison, blindness, or enhancement of various statistics like Constitution. When Midorf began the game, all she could tell about a potion was its colour and so was in danger of quaffing a potion of blindness, but once she either identified it or experienced what it does, she would remember that, and ZAngband thereafter not just as, for example, 'yellow potion' but 'yellow potion of blindness', so she would thereafter know to leave it alone (or perhaps throw it at enemies). A rather nasty danger is memory loss, a spell cast by some creatures, after which she must start again to identify things. Question: at the start of the game, how can she know which scroll is a scroll of identify, in order to read one to identify other scrolls? Answer: either just try every scroll out (dangerous) - or go into a shop and buy some, if there are any shops around. Shops, however, only occur on the surface (where she starts the game) and not down below. Formative aspect: The formative aspect is usually of great importance in most games because they give something to achieve, and is usually well and imaginatively developed in good games. In ZAngband, the formative aspect is exhibited in gaining experience, in undertaking quests, in intelligence, especially when some enemies are intelligent enough to searcher her out or choose which of their spells might most hurt her. Also, the structure of the levels is that the deeper one descends underground, the more challenging the enemies become, but also the more helpful the objects found might be. Mindorf's overall quest is to kill the Serpent of Chaos, a terrible creature found on level 100. A lot of the game before then is a preparation for this grand fight, by finding very good weapons, armour and equipment (her three staffs of power are very nice, taking 500 hitpoints off any enemy in sight, but their charges get used up, and she must recharge them). Her current, smaller, quest, is to find and kill eight Great Hell Wyrms, a kind of powerful dragon that throws fire. She has one left to kill and is currently in battle with it (see the last 30 messages about the battle at the end of Appendix 3). Lingual aspect: Mindorf receives messages from other characters and from her deity. Also, there are scrolls of rumour, which can give tips about the game - but some of these are misleading; see above. Also, each scroll has a label that identifies what type it is, but it is in an unknown language, so until she has read a scroll of identity over it, she does not know what it means? However, in ZAngband, the lingual aspect seems less important than the formative. Social aspect: Some of the creatures she meets are friends rather than enemies. Some can be made into pets, which will help her fight her enemies or go round collecting objects. Not a particularly important aspect to represent, but it gives an interesting extra touch, especially if she has Warriors of the Dawn as pets because whenever one dies another springs up in its place. It is often such extra touches which make a game fun to play. Economic aspect: She can carry only a certain amount in her backpack, and each magic wand has only a certain number of charges. She must purchase or sell things in shops - for example scrolls of identify or food or oil for her lamp. Also, she must carefully conserve her Hit Points (if they become zero, she dies) and Mana (which allows her to cast magic spells). She has a quiver of arrows (actually crossbow bolts), which she must use sparingly. This is part of the economy of fighting. Aesthetic aspect: This aspect is not particularly well developed in ZAngband. Each character has a degree of Charisma (Mindorf's currently stands at 100/130). This can be enhanced by various pieces of equipment; she once had a Cap of Beauty, which increased charisma by 4. Charisma affects how good a deal you get from shop keepers. Also, there is some humour in the scrolls or rumour. Perhaps where this aspect is most developed lies in the Uniques - characters which have names rather than being merely one of a kind. Some of these bear names that the player (not Mindorf) will know from real life, such as Robin Hood, Gollum, Smaug. Juridical aspect: This aspect is not very well developed in ZAngband. Some creatures have a price on their head because they are criminals. Some creatures steal equipment or money. Ethical aspect, of self-giving: There are beggars, which implies the concept of giving. Unfortunately, there is no way to donate money or food to them. This aspect is almost completely absent from ZAngband. It is likely that to make this aspect work, a game must be social, so that any good deeds done for altruistic reasons do not reward their doer, but rather enhance the attitude or atmosphere of the game around the player. Faith aspect: Mindorf's whole purpose in this game is the complete the quest of defeating Serpent of Chaos. Mindorf is aided by a deity, Arioch, who has power to enhance or diminish her characteristics, to give her equipment or blight her equipment. The deities in ZAngband seem rather like the Olympian gods, who interfere occasionally in the lives of mortals, either helping or hindering them. There is, of course, much more to the game than this. What this shows is why this game is very enjoyable to play over a long period, so that one does not get bored with it. I have been playing it occasionally for about ten years! I usually play it for about half an hour as relaxation after a hard day's work - but that is HLC, not ERM. It is the quality of ERM which makes it worth playing. Note that whereas in HLC we are subject to the laws of all the aspects as given, in virtual reality, some of the aspectual laws might be modified, as was discussed earlier. So, for example, teleporting becomes possible. But the modifications to aspectual laws are usually relatively sparse, and usually bear some relation to real aspectual law. For example, the real aspectual law that we die when harmed and die once is honoured in that there is still death due to harm in the virtual world but modified to allow a certain number of resurrections. Now let us widen the discussion away from computer games to other types of software. Not every information system is required to represent meaning from every aspect. In some specialised types of software there are some aspects that would be irrelevant. But it is generally the case that more aspects should be represented than might at first be expected, because when the IS is used these unexpected aspects become important. In particular, it is usually the case that software of a given aspectual type (see earlier) should have represented within it information of much more than that aspect. For example, SatNav systems might be qualified by the spatial or kinematic aspect, but really useful ones might also inform the user about: » restaurants (biotic and aesthetic aspects) » theatres (aesthetic) » places of worship (faith aspect) » places of ecological significance (biotic) » historical sites (formative, social aspects) and so on. All this information from other aspects needs to be represented within it. Likewise, it is likely that a patient database will represent not only biotic information (about health) but economic (costs and payments), faith (religious requirements), social (next of kin), and so on. So remember: it is usually a good idea to think about every aspect, and deliberately remove those that are proved to be irrelevant, rather than overlooking aspects because of laziness. 5. QUALITY OF ERM What makes for good represented meaning? One is that it should do justice to the user, to their life and work (HLC). For example, a computer game should be fun, while a database need not be. That, however, is the link the ERM has with HLC, and will not be considered here. 5.1 Quality Criteria What we are concerned with here, though, is the quality of the information itself regardless of the life and work of the user. Let us, yet again, use (most of) the aspects to help us separate out the quality issues (think about a database or website): » Analytic - Is the information content clear, or is it confused? Does it help the user gain a clear picture when they engage with it? » Formative - Is the information well or poorly structured (for example a blog might have a well-structured argument or story)? Does it enable the user to achieve what they might reasonably want? » Lingual - Is the information understandable? (This overlaps to some extent with HCI; indeed the lingual aspect is the main link between ERM and HCI.) » Social - Is the information socially acceptable? Does it show respect or disdain? Does it depend on a lot of connotative meanings and idioms, a lot of in-jokes that only a few people would understand? » Economic - Is the information efficient or wasteful? » Aesthetic - Is the information interesting or boring? Does it show harmony so that user can gain a whole picture, or is it rather bitty, so that they remain confused? When the user engages with it, do they experience delight or disquiet? » Juridical - Does the information do justice to the domain it represents: is it relevant and accurate (including timely)? Some more on relevance and accuracy is found below. » Ethical - Is the information generous or mean, not just to the users but to others? Does it give exactly the information it should, or does it give extra, to make the user more comfortable? » Faith - Is the information faithful? Do the creators really believe that the topic or domain of knowledge represented is important? 5.2 Breaking the Rules? It is the essence of some games, especially in the higher levels, to mislead the user or make things more difficult for them, to give a challenge. For this reason, it is appropriate in some games to break some of the aspectual rules of quality of information. Another reason is for humour and surprise. Ways of misleading the user include: » hiding useful objects or dangers, so the user must keep alert and even search for things. This goes against the formative criterion above. In ZAngband, traps (which if stepped on can do nasty things) are hidden, and only become evident if the character has high levels of perception or has a magic device that can reveal where they are. In other games, things are hidden by camouflage. » Disguising one item as something else. This goes against the analytic criterion above, because it reduces clarity; for example in ZAngband, some creatures mimic objects like doors, coins or the wall of the cave. » Giving false information. This goes against the juridical criterion above, for example in messages passed to the character by others or in pieces of paper found lying around. IN ZAngband, there are scrolls of rumour. This should only happen in a game. In a patient database, such deliberate inaccuracy would be intolerable, and the main inaccuracy in such systems arises from mistakes or carelessness. 5.3 Relevance of Represented Meaning The patient database contains information on the drugs given to the patient; this is relevant information. It probably does not contain information on the type of car the patient drives, because such information would probably be irrelevant. Relevance of meaning- content means shaping the content to the purpose (or purposes) of the IS. All the information should (usually) be designed to serve this purpose. Relevance to the purpose of an IS is important when the designer of an IS must decide what information to include in it and what to exclude. Suppose you are reading a blog, and find its content is irrelevant to you. What is your reaction: » lost and confused? » cynical? » annoyed? » amused? It probably depends on what you are doing at the time. 5.4 Accuracy and Realism In Accuracy and realism relate to all the aspects, not just the qualifying one(s). The aspects of the represented meaning are those of the domain meaning which are signified by the symbols that constitute the IS. Especially in a computer game or a virtual reality system, the following guidelines apply: » The norm of diversity: In general, every aspect of the lifeworld of the domain should be represented. This is especially important in software for ill-structured domains, and computer games and virtual reality social systems. If aspects are missing, then the whole feels rather thin and unreal. It feels more like a machine than an environment. » The norm of richness: Each aspect must be represented in the richness with which we encounter it in the real world. For example, under the analytic aspect of distinction, we classify and identify objects, and in everyday life we have several degrees to which we can do this. So when the player of ZAngband finds an object they must be able to detect its general type immediately (two-handed sword, soft leather shoes, gold ring, etc.), but they must also be able to identify the object's quality - such as how effective the sword is in being wielded and doing damage - and in ZAngband this requires the player to zap a Rod of Perception or read a Scroll of Identify. There is also a third, special or secret degree of identification. These degrees of identification make the game much more interesting. » The norm of multi-aspectual trustworthiness: The user should not be lulled into a false sense of reality. In the mid-1990s film Gladiator, the (virtual) Colosseum looked very realistic (visual, psychic aspect). But the crowds, seen from above, looked unreal because the people were almost equally spaced, rather than huddling in groups as real crowds do (social aspect). Beware of maximizing realism in one aspect and ignoring others. It is often preferable to deliberately degrade visual faithfulness in order to avoid false impressions of reality (as in ZAngband's diagrammatic, 2D view of the territory). » Norms for virtual worlds: What is the ERM norm for virtual worlds, such as in games? What kind of virtual reality 'rings true'? Bartle [2004,p.66] discusses why one Internet game succeeded where another failed, including: "If what you see looks and behaves like reality, you feel you're 'there' more than if it looks and behaves like a gridwork of platonic solids. Recognising that people have expectations of degrees of reality within the virtual world. Fulfilling these expectations leads to increased immersion and denying it leads to decreased immersion." While fictitious entities (hobbits, magic weapons, etc.) are acceptable, they must behave as though subject to laws we know. The author does not know of any other attempt to explain this. » The norm of flexibility: Ensure user is aware of opportunities to use it in ways not anticipated, and stimulate them to take advantage of these. Build up their courage and hope where necessary. 6. CONCLUSION Considering human engagement with meaningful information content is important in several ways, and we have seen three ways of understanding this issue by means of aspects: understanding different types of software, assessing the completeness and realism of content, and criteria for judging the quality of information content. We can return to the three questions we posed at the start: » How do we judge quality of information content? By looking to see which aspects the content covers and judging whether this is appropriate in relation to how the software will be used in everyday life. » How do we differentiate virtual reality from 'real' reality? What laws apply to each? Sometimes the laws of real life are modified within virtual reality. » Why can false information be so plausible? (e.g. fake identities in social networking, false emails offering us money) The problem is not in the represented meaning-content but in an attitude taken in real life; i.e. it is an HLC matter. APPENDIX 1 - EXAMPLES Example 1: "Number of books on loan: 12" - quantitative "Number of books on loan: 12 (Max 15)" - economic (with quantitative in service of economic) Copyright (c) Andrew Basden. 20 September 2008, 22 September 2009, 22 December 2009. 20 September 2010.