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<Paper uid="T78-1002">
  <Title>What Makes Something &amp;quot;Ad Hoe&amp;quot;</Title>
  <Section position="2" start_page="0" end_page="0" type="metho">
    <SectionTitle>
PART III
</SectionTitle>
    <Paragraph position="0"> Just to give the reader a feel for the nature of ad hoc thinking in AI that I believe to be worth espousing, I will now consider a problem that I have recently been working on. We have had a problem in representing certain kinds of political concepts in our old representation, Since we have been very concerned with the problem of newspaper story understanding it is very important that we be able to handle such concepts in a clean representation that will facilitate computer under stand ing.</Paragraph>
    <Paragraph position="1"> The problem we are attempting to solve can be illustrated by looking at a recent New York Times headline: &amp;quot;Catawba Indians land claim supported.&amp;quot; The problem here is to be able to represent what &amp;quot;land claim&amp;quot; and &amp;quot;supported&amp;quot; mean. We know that a land claim is more than what we might use to represent it in Conceptual Dependency.</Paragraph>
    <Paragraph position="2"> Something like &amp;quot;Indians MTRANS land be possessed by Indians&amp;quot; is possibly true, but it misses the point. A &amp;quot;land claim&amp;quot; is in a sense a petition to a higher authority to resolve a dispute between two parties. That is, the Indians are saying to the U.S. Government, &amp;quot;this land is ours&amp;quot;. It may not be possible to infer the particulars of this land claim. Indians have been known to take the land by force, to file doc~nents in government offices, to complain to newsmen and so on. The important point here is that we really need not know* and in most cases a reader would not bother to worry about, exactly which method has been selected. Rather. a reader feels that he understands such a sentence when he has been able to identify the relationships and aims of the parties involved.</Paragraph>
    <Paragraph position="3"> A program must recognize that a &amp;quot;land claim&amp;quot; is a type of petition to a higher authority to resolve a dispute about land ownership. We do not know who presently owns the land* but we know enough about ownership of property to infer that there is probably a counter petition of some sort.</Paragraph>
    <Paragraph position="4"> We also know about petitions to authority. They usually get resolved by the authority. In this case then, &amp;quot;supported&amp;quot; refers to the decision of the authority in the case.</Paragraph>
    <Paragraph position="5"> This information can be represented graphically by a kind of triangle (example I);  In this triangle (a) represents the dispute between the Indians and the owners of the land, ) represents the appeal to authority to resolve the dispute made by the Indians* and (c) represents the authority's decision.</Paragraph>
    <Paragraph position="6"> Triangles of this sort have use in representing any type of dispute. For example, in  (2) and (3) such triangles can also be constructed : (2) Burma appeals to UN to settle border dispute with Thailand.</Paragraph>
    <Paragraph position="7">  Of course* these triangles just suggest the basic relationships involved. In order to add substance to the bare bones of the triangles we shall have to deal with some representational issues that are being glossed over here. The important point at this juncture is that there is an essential similarity across (I)* (2) and (3)* that the similarity must be represented in some way, and that that similarity can be exploited for use in an understanding system.</Paragraph>
    <Paragraph position="8"> The first representational problem we encounter in trying to make explicit much of what is implicit in the triangle representation is that we will need to design a new set of ACTs to take care of the various relationships.</Paragraph>
    <Paragraph position="9"> In the primitive ACTs of Conceptual Dependency we have a system that represents physical actions by using a small set of basic actions that can combine in various ways to describe detailed or complex actions that underlie seemingly simple verbs and nouns. The primitive ACTs do not account for intentionality and goals underlying physical action. To account for such things we devised a complex apparatus discussed in Schank and Abelson (1977). If we wish to account for social events, we will need a system of basic social ACTs to represent the social actions that comprise the events. I term these &amp;quot;basic social ACTs&amp;quot; rather than primitive ACTs because in the end most social ACTs have some physical manifestation. Often their physical manifestation is uninteresting however. For example a government decision may be MTRANS-ed in a variety of ways. The manner of the MTRANS (written* announced in a speech, etc) is often not significant with respect to the overall social effect of the action. Furthermore the MTRANS itself is only slightly interesting. The standard inferences from MTRANS apply, but there are some highly significant inferences that need to be made that are not obviously available.</Paragraph>
    <Paragraph position="10"> For example, the most significant inference to be made from an authority's decision is that simply by virtue of that decision something has actually happened. That is * a government authorization is a truly performative ACT. Thus, if the government says some property is mine, or that a man is a criminal, then it is so by virtue of their saying it. Similarly other authority figures have the same power. A professor can say a thesis is finished and a student has a Ph.D.</Paragraph>
    <Paragraph position="11"> and these things are the case by virtue of his saying it.</Paragraph>
    <Paragraph position="12"> Not all authority's decisions are like this to be sure. Sometimes an authority gives an order and that order must be carried out for the decision to have effect. Frequently these orders come about as a result of a governmental decision or authorization. If the government says the land belongs to the Catawba Indians, then it does, but they may have to send in the National Guard to get the original owner off the property.</Paragraph>
    <Paragraph position="13"> What I am proposing then is two basic social ACTs - AUTHORIZE (abbreviated AUTH) and ORDER.</Paragraph>
    <Paragraph position="14"> AUTH is something only an authority can do. (This is a bit circular actually since if you actually can AUTH then that defines you as an authority.)  In a sense then, an authority is one who when he acts like he is doing an AUTH (that is he does the physical ACTs that ordinarily correspond to an AUTH) in fact causes some things to happen as a result of the AUTH that were supposed to be the results of the AUTH. In other words, you cannot really tell if an AUTH has taken place until it becomes clear that the person doing the AUTH can back up his AUTH in some way.) The object of the AUTH is the authorization or new state of the world. AUTH takes a recipient, namely the relevant parties in the dispute.</Paragraph>
    <Paragraph position="15"> ORDER is a frequent inference of AUTH. The government can AUTH the army to fight a war, but that doesn't, simply by virtue of the statement, imply that they are fighting it, A subsequent ORDER is required that carries with it the implicit punishments that are relevant in carrying out an order.</Paragraph>
    <Paragraph position="16"> Why can't we do these things with CD primitives we now have? What is the advantage of these new ACTs? To answer these questions, we need to look at the purpose of a primitive ACT.</Paragraph>
    <Paragraph position="17"> It is possible to represent ORDER in CD for example. The verb 'order&amp;quot; means to MTRANS to someone that they must do a particular action or face some (usually implicit) consequence.</Paragraph>
    <Paragraph position="18"> Thus, implicit in the verb &amp;quot;order', but explicit in the CD representation for 'order', is the idea that if the required ACT is not performed, then someone will possibly do something to harm the recipient of the order in some way. This implied punishment is a part of the concept 'order&amp;quot; but is it necessary that we think of it each time that we understand an &amp;quot;order&amp;quot; to have taken place? The same question can be asked with respect to 'authorize'. We understand what authorization or governmental decision is, but we need not access all that information each time we understand the word. Consider the problem of explaining the meaning of these words to a child for example. It is very difficult to explain them precisely because they are so complicated at the level of physical primitive AC~s, Yet these ideas are really not complicated at all at a social level of ACTs. Such simple concepts such as ORDER and AUTHORIZE form the basis of the organization of societies. What is complex at one level is simple at another. This idea of nested levels of complexity, each with their own set of primitives, is a very important one for the representation of information in artificial intelligence. By choosing a good set of primitives we can effectively organize what we need to know. Thus, ORDER and AUTHORIZE have inferences that come from them just as the physical primitive ACTs do. The main difference is that these basic social ACTs are not primitive in the same sense. They can be broken down, but we would rarely choose to do so. The use of these new basic ACTs is much like the use of the original primitive ACTs. We can predict what will fill slots reasonably in a conceptualization and make inferences about slot fillers and consequent inferences as we would any conceptualization. Thus we represent sentences such as the following using AUTH:  In (4) we have chosen to ignore representing &amp;quot;segregation&amp;quot; for the moment, since it is obviously complex. Supreme Court decisions are AUTHs. They also carry with them (as do most AUTHs) an implicit ORDER for 'punishment&amp;quot; if certain circumstances are not met. The straightforwerd inference from (4) then is that someone practicing segregation can expect to be punished.</Paragraph>
    <Paragraph position="19"> Policemen are authorities also. In (5) the ticket is a written manifestation of an AUTH that either puts the driver in a DEFENDANT role in a $TRIAL script or forces him to pay a fine. The instrument of the AUTH is the actual PTRANS of the ticket (left out here). The important point here is that we could represent (5) using PTRANS only. However, what we would be describing is the physical ACT itself when it is the social ACT that is significant here. (When I was young there was much talk of bad kids getting &amp;quot;JD cards&amp;quot;. I never understood what was so horrible about that.</Paragraph>
    <Paragraph position="20"> Couldn't they just throw them away?) The social significance of an ACT must be represented if it is understood.</Paragraph>
    <Paragraph position="21"> Now that we have presented these two ACTs let's return to our triangle:</Paragraph>
  </Section>
  <Section position="3" start_page="0" end_page="0" type="metho">
    <SectionTitle>
AUTH
</SectionTitle>
    <Paragraph position="0"> ~followed by a possible ORDER) We have named one side of the triangle. The other sides represent ACTs as well. The complete triangle is as follows: A</Paragraph>
  </Section>
  <Section position="4" start_page="0" end_page="12" type="metho">
    <SectionTitle>
PETITION/ ~AU~H
/ ~ (ORDER)
DIS PUTE
</SectionTitle>
    <Paragraph position="0"> The ACT PETITION represents an individual or group's act of requesting AUTH&amp;quot; s from an authority. Thus a &amp;quot;civil suit&amp;quot; is a PETITION to the courts using some legal scripts. A protest demonstration is a PETITION to unstated Ii authorities using some demonstration script. The point here is that we cannot do away with the scripts that describe the actual physical manifestations of these events. However, the scripts are instr~ents of the social ACT involved  - PETITION. The most important inference from PETITION is, of course, that an AUTH is expected that will resolve the issue that is the object of the PETITION.</Paragraph>
    <Paragraph position="1">  The issue that is the object of the PETITION is the DISPUTE itself. DISPUTE takes two actors (one of whom may be quite passive). The object of the DISPUTE is the issue involved. DISPUTE takes no recipient as it is not an inherently directed ACT. It is the ACT of PETITION that directs it to a particular authority who can AUTH something that will resolve it.</Paragraph>
    <Paragraph position="2"> We are now ready to deal with sentence (I) (Catawba Indians Land Claim Supported). The representation using the new social ACTs is:  Since this representation is not as easy to write as the triangular one, we shall continue to use triangles in the remainder of the paper. Thus (I) is: U.S. Gov't.</Paragraph>
    <Section position="1" start_page="0" end_page="12" type="sub_section">
      <SectionTitle>
Indians
OWNS(land)&lt;=&gt;Indians
Other
</SectionTitle>
      <Paragraph position="0"> OWN(land)&lt;=&gt;? We will leave out the arrows and the ACTS for diagrammatic purposes, but the above triangle should be understood as containing all the information given in the CD diagram for (I). (Actually~the triangles contain more information.) Triangles provide us with a method for representing the social significance of actions. As with any other representation scheme, the advantage of the symbols we create can only be in the new symbols or actions that they spawn. That is, it is the inferences that come from the triangles that are of key importance. When we created the original primitive ACTs we said that PROPEL was no more than the set of inferences that it fired off. The same is true here, so we must ask what these inferences are.</Paragraph>
      <Paragraph position="1"> The first thing we can recognize about potential inferences here is that they will come in two varieties. The first are the inferences that are fired off from the new social ACTs that we have created. The second kind are those that come from the triangles themselves. That is, there should be patterns of triangles that are recognizable for the triangles they spawn as well as a set of inferences that come from the fact that certain triangles exist.</Paragraph>
      <Paragraph position="2"> As examples of this let us consider again sentence (2): (2) Burma appeals to UN to settle border dispute with Thailand.</Paragraph>
      <Paragraph position="3"> Since the representation of (2) involves a PETITION we can employ the inference rules that are fired by PETITION. Some of these are: a. For every PETITION we can expect a corresponding AUTH.</Paragraph>
      <Paragraph position="4"> b. For every PETITION there was probably a DISPUTE that gave rise to it.</Paragraph>
      <Paragraph position="5"> These rules lead us to the inferences available from AUTH and DISPUTE. Of course, inferences from inferences have a lower probability of truth, so for (2) the inferences below would be somewhat less certain.</Paragraph>
      <Paragraph position="6"> c. An AUTH can cause a DISPUTE to end.</Paragraph>
      <Paragraph position="7"> d. An AUTH can cause a PETITION to a higher authority from the party unfavorably affected by the AUTH.</Paragraph>
      <Paragraph position="8"> e. An unfavorable AUTH can cause a rebellion; or lack of acceptance of the validity of the AUTH. This can give rise to ORDERs to effect the AUTH in the case of individuals versus governments or wars in the case of governmental conflicts.</Paragraph>
      <Paragraph position="9"> f. An AUTH causes a new state of the world to exist, often ending an old state in conflict with the new state.</Paragraph>
      <Paragraph position="10"> g. A DISPUTE can cause one party to PETITION. h. A DISPUTE can cause a PROPEL to cause damage to occur for individuals, or a WAR triangle to be initiated for countries.</Paragraph>
      <Paragraph position="11"> There are, of course, a great many more of these kinds of inferences than we are listing here. The above list is mostly intended to give the flavor of basic social ACT inferences. It is important to note that the social ACTs give rise to inferences at both of the other levels of representation besides those at the same level of representation. That is, given a social ACT we may be able to infer another social ACT, a new primitive ACT, or a new triangular representation. Thus, for (2) we have two representations to start with: one is at the standard CD level and uses MTRANS; the other is at the social level and uses PETITION. Both of these representations would be available as output from the parser.</Paragraph>
      <Paragraph position="12">  The MTRANS representation would fire off inferences about the methods of communication possibly used - that the UN now knows about the problem and so on.</Paragraph>
      <Paragraph position="13"> The PETITION representation would fire off inferences about the expected AUTH from the UN. Since we know how the UN does its AUTHs, this would fire off a UN script of some kind that dealt with voting and debate. PETITION would also cause DISPUTE to be inferred which would cause inferences about the kind of methods possibly employed by the quarreling countrles~ both in creating the DISPUTE and escalating it.</Paragraph>
      <Paragraph position="14"> The existence of the PETITION-AUTH-DISPUTE triangle would fire off an inference that the country kind of triangle existed. Thus, a new triangle that was lopsided showing possible aggression from Thailand towards Burma would be created. This triangle would in turn fire off inferences about attempts to RESOLVE the DISPUTE (one of which was (3) itself) and weuld predict an escalation towards the WAR triangle with its normal inferences if a RESOLVE did not take place. Although the above is rather sketchy, the point should be clear. We need additional representational mechanisms to handle the many levels at which statements can be interpreted. Triangles provide us with a new set of inference rules providing more power to the understanding system. Are they ad hoc? Of course they are. My point is simply that such ad hoc mechanisms will either solve the problem or help us create a more general solution that will solve the problem. The proRram that we are writing that uses triangles is also ad hoe. Is is a kludge? No. If it were it wouldn't be worth a thing. But, here again, if the program we write can handle many examples as we rewrite it because of what we have learned from it, then it will have been werthwhile.</Paragraph>
      <Paragraph position="15"> The program below reads newspaper headlines in English and generates, by use of triangles and the inferences available from triangles, a paraphrase of the input. This English paraphrase is generated by the program.</Paragraph>
      <Paragraph position="16">  Court to rule that they own the land.</Paragraph>
      <Paragraph position="17"> The Catawba Indians requested a Federal Court to rule that the land is owned by t hem.</Paragraph>
      <Paragraph position="18"> The Catawba Indians appealed to a Federal Court.</Paragraph>
      <Paragraph position="19"> The Catawba Indians asked a Federal Court to rule that they own the land and it decreeed that the land is owned by them.</Paragraph>
      <Paragraph position="20"> \[ Generating inferences from CON4 \] &gt;(TELL-STORY) The Catawba Indians and the other parties disagreed over the ownership of the land.</Paragraph>
      <Paragraph position="21"> The Catawba Indians requested a Federal Court to rule that they own the land.</Paragraph>
      <Paragraph position="22"> A Federal Court decided that the land is owned by the Catawba Indians.</Paragraph>
      <Paragraph position="23"> The other parties will probably appeal the decision.</Paragraph>
      <Paragraph position="24"> The other parties might use force against the Catawba Indians to assert that they own the land.</Paragraph>
      <Paragraph position="25"> ***** This program was written by Jaime Carbonell and Stephen Slade.</Paragraph>
    </Section>
  </Section>
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