Archive: March 2nd, 2009

Roger Schank: Scripts, Plans, Goals, and Understanding

[Readings] (03.02.09, 10:48 pm)

Roger Schank is a big influence on AI. In comparison to many other voices, his writing is along the variety of traditional AI and cognitive science, but a close reading of his work suggests that, while his influence on AI concepts has been profound, his approach is more cautious than that of Newell and Simon, advocating computation as a means for testing a theory of cognition, rather than asserting that minds are computational.

This particular book is generally about cognitive science, but more specifically about the understanding of stories. When one hears the sentence “I was hungry so I went to the restaurant,” it is easy to figure out the meaning, given what we know about hunger and restaurants and whatnot. Computers lack this background knowledge, so Schank works to articulate how that knowledge might be captured and represented computationally. There are two ways of looking at this knowledge, the first is the perspective of scripts, and then there is the perspective of plans. Schank moves from scripts to plans, finding the latter more robust and powerful, but I think that scripts are much more promising, especially in context of social interaction and a situation-centric view of cognition.


This book was written after Newell and Simon, and after Weizenbaum, but before further development in cognitive science. Schank reveals a belief in the overlap of problems between computers and humans, which is the conceptual apparatus. However, Schank does not necessarily assert that computational and cognitive concepts are the same (as does Newell). I think that the overlap is smaller than Schank suggests, but his caution is encouraging given the period of circumstances.

The foundation of this work is the Conceptual Dependence Theory, which is composed of five main rules, the first two of which are important and I have copied here: (p. 11)

  1. For any two sentences that are identical in meaning, regardless of language, there should be only one representation.
  2. Any information in a sentence that is implicit must be made explicit in the representation of meaning of that sentence.

These give a strongly linguistic foundation to language, and suggest that meaning and cognition should come through the understanding of concepts and sentences. I find this to be a dubious supposition. The assertions also suggest that the meaning of a sentence can be non-problematically separated from its form, which is also contestable. This suggests that it is even possible to express statements analytically and completely, without implicit information, which is also problematic. Schank organizes conceptual dependency as deriving from several primitive acts. These are:

  1. ATRANS: Transfer of possession, ownership, or control
  2. PTRANS: Change of the physical location of an object
  3. PROPEL: Application of a physical force to an object
  4. MOVE: Move of oneself or a part of oneself
  5. GRASP: To grasp an object
  6. INGEST: To “take in” or consume something into one’s body
  7. EXPEL: To expel something from one’s body
  8. MTRANS: Transfer of some mental information
  9. MBUILD: Construction of new information
  10. SPEAK: To produce sounds and say something
  11. ATTEND: To focus one’s senses on something

Note that the phrasing of these asserts a kind of literalism and preoccupation with physical situations. On one hand, that is good, because it suggests some sort of anchoring in embodiment, but it also pre-loads the conceptual system with many anchored terms revolving around production, physical movement, and ownership. This does not, for example, suggest of ways to express emotions, build relationships, or change one’s mood or disposition. These could all be expressed within the system, but secondarily, whereas physical movement and ownership are built in at the first level.

The theories of cognition in AI must be specified fully. Schank gives an example of someone asking how to get to Coney Island, and being told to take the ‘N’ train to the last stop. These instructions are described as inadequate, at least for a computer, because all kinds of background knowledge are required to make sense of how to use the subway in the first place. This is a good example of the difference between situational and top-down models. Schank is proposing a top-down structure, where a general plan: go to Coney Island, is made up of smaller and smaller parts: take the ‘N’ train to the last station (which consists of going to the metro station, getting a fare card, going through the gate, getting on the train, etc etc etc). I agree that an AI simulation of cognition must know how to deal with this low level knowledge, but in a situational system, this knowledge really should be secondary. In context, the directions are certainly sufficient, and at the right level of abstraction, the finest granulation of instructions are not necessary.

Causal Chains

This chapter discusses ways of interpreting sentences with a distressing degree of literalism. The logic is used with a kind of causal chaining. Interpretation is described as a filling in of the blanks in a causal chain. For example, Schank gives the sentence “John cried because Mary said she loved Bill.” This sentence, with its face value taken at the most literal level, is absurd, John cried because Mary’s speaking. However, this is not the meaning of the sentence, at all. Schank argues that the reader constructs a causal chain behind the contents of the sentence, that Mary speaking to John transfers factual knowledge of Mary loving Bill to John, and this is what made John cry. The degree of chaining in this is ridiculous, as much as in the supermarket example given by Cohen, Morgan, and Pollack. I think that understanding of these sentences has much more to do with common usage an practices of use, or even in a sense of internalized “grand narratives” than causal chains. Schank gives a calculus of causation which is built from actions, states, reasons, and enabling.


The chapter on scripts is rather hilarious from my perspective. To me, scripts are the most productive thing to be gained from an analysis of Schank’s book, however, in context, they are used only as a stepping stone to the discussion of plans in the next chapter.

Scripts are very useful structures to analyze. Scripts structure information that is relevant in the context of a particular situation, and organize new inputs and events in context. This is consistent with my understanding of models, and also with Goffman’s sense of framing. The discussion Schank gives is still preoccupied with story comprehension, especially as relates to included versus excluded information. For example, if someone is comprehending a set of sentences and knows what script is being followed, it will be easier for the reader to identify and contextualize the meaning of each sentence.

Schank explains scripts as being composed of props, roles, states, entry conditions, and resulting conditions. The goal of developing this formulation is the SAM program (Script Applier Mechanism), which understands (presumably) scripted stories, and is able to answer questions about them. The script described is the “restaurant script”, where a customer can go to a restaurant, order something, eat it, leave a tip, pay, and leave. Given gaps, it is still possible to piece together what might be happening in a story that abides by this script. Narratively, these are still very uninteresting, but I think they have the potential to be more meaningful. For instance, scripts could be annotated with other layers of meaning that give some sort of narrative value to how a character might act within the script.

Scripts are fitted with metadata, specifically that which describes how, based on events, the ssytem will recognize what scripts to use. Script headers describe the preconditions, instrumental relations, locales, and so on, used by scripts. This helps a script analysis program understand what script might be in operation at a given moment. This is not complete, but gives some background to the situation and ambiguity problems that come up with a situational model of interaction.

Schank moves to examine how to handle statements that are not immediately relevant to the script. Notably, he examines breaches and distractions. Distractions are not especially relevant to me, but breaches are extremely useful. Social situations are full of scripts and breaches in those scripts. From the perspective of simulation, when breaches occur, agents scramble to recontextualize and reground themselves in some sure footing of knowing how to interact. Scripts designate social rules, procedures, and conventions. Usually what is interesting narratively are the breaches. Frequently breaches allow scripts to interact simulaneously and play off each other. Schank gives a listing ways to handle unexpected inputs within scripts: (p. 53)

  1. Does it specify or imply the absence of an enablement for an impending script action? (Obstacle)
  2. Does it specify or imply that a completed action was done in an unusual manner, or to an object other than the one(s) instantiated in the script? (Error)
  3. Does it specify an action which can be understood as a corrective resolution of an interference? (Prescription) This question would be activated when an obstacle is inferred from or described directly in the text.
  4. Does it specify or imply the repetition of a previous action? (Loop) This is activated when an error is inferred from or described directly in the text.
  5. Does it specify or imply emotional expression by the actor, likely to have been caused by an interference? (Reaction)
  6. Does it specify or imply that the actor will have a new goal that has nothing to do with the original script? (Distraction)
  7. Does it specify or imply the motivated abandonment of the script by the main actor? (Abandonment)

Note that emotional responses are “unexpected inputs.”

Schank poses scripts as a powerful component to cognition and to understanding the world. People adapt and transform scripts, but this does not mean that they fall under the general category of knowledge transfer (something we know to be flawed, eg Lave). This is precisely because scripts are known and learned from experience, and by being experienced. This dimension is not discussed (Schank may not even agree with it), but I believe this is a potent observation.


Turning to planning, Schank makes a claim here that I totally disagree with: that scripts come from plans. As described, plans are means of satisfying goals. In execution, plans make use of several low level behaviors. For example, the plan “USE(x) = D-KNOW(LOC(X)) + D-PROX(X) + D-CONT(X) + I-PREP(X) + DO”, where each of the D- expressions are subgoals that can be satisfied by other actions. The focus of discussion is still story comprehension, so the object is to understand the plans of story characters.


Schank introduces several types of goals:

  1. S: Satisfaction: satisfying a basic need
  2. E: Enjoyment: doing something for the sake of pleasure
  3. A: Achievement: attaining some desirable outcome
  4. P: Preservation: maintaining some desireable state
  5. C: Crisis: responding to a sudden pressing emergency
  6. I: Instrumental: a goal that realizes the precondition of another goal
  7. D: Delta: effects a state change in the world

This general system of goals has been influential and used by others, notably Ortony, Clore, and Collins. This is still bound in understanding stories, but is reasonable as a general scheme of understanding motivation. The goal system alone is consistent with the idea of having conflicting goals.


Schank introduces the idea of themes, which make sense for story understanding, but are totally neglected within conventional AI. This asserts that goals and plans work in context of some broader theme, which guides the goals that occur and the plans to achieve them. In terms of stories, they are what a story might be about, for instance, success, interpersonal relationships, and so on. This serves as a filter or model to focus on select elements of a story world.

Reading Info:
Author/EditorSchank, Roger
TitleScripts, Plans, Goals, and Understanding: An Inquiry Into Human Knowledge Structures
Tagsai, specials
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Linda Hutcheon: A Theory of Adaptation

[Readings] (03.02.09, 4:06 pm)

A Theory of Adaptation presents a comprehensive and general theory of adaptations. Adaptations are widespread and universal. They seem common and nautral, but pose curious problems in content, structure, and intertextual politics. The work here looks to develop a theory of adaptations in general, not just with novels to film. Hutcheon wishes to consider adaptations as lateral, not vertical. One does not experience adaptations successively starting from the original work, rather the works are a large collection to be navigated. One might see an adaptation before the original. Hutcheon also wishes to view adaptations as adaptations, not as independent works. What makes them work and desirable as adaptations? There are three ways of story engagement: telling, showing, and interactivity.

One dimension that is missing from this, I think, is a critical aesthetics of adaptations. Given a set of adaptations, how can or should one judge them with respect to each other and the adapted work? In my study of games, I think that aesthetics can come from thinking about the mechanics and models of the narrative worlds, but this is, of course, just one perspective. Hutcheon avoids judgments specifically for the purpose of opening up literary acceptance to legitimize adaptations in the first place. This perspective comes particularly from translation studies, which generally places the original work and language on a pedestal, asserting its supremacy to any translation or adaptation that may be made of it. Only recently has the perspective changed to view translations as weaving the original text into the culture of the target language (Bassnett), or seeing translation as breathing life into a text (Toury).

Beginning to Theorize Adaptation

Adaptation always exists in a secondary relationship with the original, but despite their supposed inferiority, adaptations are pervasive. Adaptations also dominate their own media. The most heavily awarded films are adaptations. Hutcheon suggests that the pleasure of adaptation from the perspective of the consumer comes from a simple repetition of a beloved story with variation. Far from losing it, adapted works keep and extend Benjamin’s Aura. Adaptations nonetheless add a financial and economic dimension to production. Adapted works are popular among content producers because they are “proven” and already have a culture and fan base that are likely to be interested in the adaptation.

To help steer clear of the common practice of devaluing adaptations, Hutcheon foregoes the use of terms such as the “original” or “source” text, but instead calls the text from which adaptations are made the “adapted text”.

To borrow Michael Alexander’s term, adaptations are palimpsestuous works, works that are haunted by their adapted texts. Hutcheon wishes to avoid resorting to fidelity criticism, which originates in the (often false) idea that the adapters wish to reproduce the adapted text. There are many reasons why adapters may wish to adapt, which can be as much to critique as to pay homage. There are three dimensions to looking at adaptations: as a formal entity or a product, as a process of creation, or as a process of reception. Adaptation is simultaneously a process and a product.

Hutcheon distinguishes between adaptations and sequels and fanfiction. Sequels and fanfiction are means of not wishing a story to end. This is a different goal than the recreation done by adapting a work. There is a legal term to define adaptations as “derivative works”, but this is complex and problematic. Adaptation commits a literary heresy that form (expression) and content (deas) can be separated. To any media scholar, form and content are inextricably tied together, thus, adaptations provide a major threat and challenge, because to take them seriously suggests that form and content can be somehow taken apart. This raises another difficult question: what is the content of an adaptation? What is it that is actually adapted? One might consider this to be the “spirit” or “tone” of a work. Adapting a work to be faithful to the spirit may justify changes to the letter or structure in the adaptation. In my perspective, the content of adaptations is (or should be) the world of the adapted text.

Hutcheon specifically addresses videogames and how they engage in activity beyond problem solving. She suggests that if a film has a 3 act structure, then gameplay is only the second act. Excluding the introduction and the resolution, gameplay is tied up with solving problems and working to resolve conflicts. Games adapt a heterocosm: “What gets adapted here is a heterocosm, literally an “other world” or cosmos, complete, of course, with the stuff of a story–settings, characters, events, and situations.” (p. 14) A game adaptation shares a truth of coherence with the adapted text. The format may require a point of view change (for example, in the Godfather game, where the player takes on the role of an underling working his way up). Other novels are not easily adapted because the novel focuses on the “res cogitans”, the thinking world, as opposed to the world of action. This is a point that I would disagree with Hutcheon’s assessment, I think that even the thinking world of a novel abides by rules and mechanics, that these mechanics may be simulated or expressed computationally, but they may not be suited to the conventions of action and spatial navigation popular in games right now.

Hutcheon notes that some works have a greater propensity for adaptation than others, or are more “adaptogenic” (Groensteen’s term). For instance, melodramas are more readily adapted into operas and musicals, and one could extend that argument to describe how effects films tend to get adapted into games. This may be due to the fact that there are genre conventions that might be common to both media.

Adaptation may be seen as a product or a process, the product oriented perspective treats it as a translation (in various senses), or as a paraphrase. The product oriented perspective is dependent on a particular interpretation. As a process, it is a combination of imitation (mimesis) and creativity. Unsuccessful adaptations often fail (commercially) due to a lack of creativity on behalf of the adapters. There is a process of both imitating and creating something entirely new, but in order to create a successful adaptation, one must make the text one’s own.

There is an issue of intertextuality when the reader is familiar with the original text. But there can become a corpus of adaptations, where the subsequent works are adaptations of the earlier ones, rather than the adapted text itself. This has been the case of texts which have had prolific series of adaptations, such as Dracula films (Hutcheon’s example), as well as Jane Austen’s works. These works are “multilaminated”, they are referential to other texts, and these references form part of the text’s identity, as a node within a network of connected texts.

A final dimension is the reader’s engagement, their immersion. Readers engage with adaptations with different mdoes of engagement. “Stories, however, do not consist only of the material means of their transmission (media) or the rules that structure them (genres). Those means and those rules permit and then channel narrative expectations and communicate narrative meaning to someone in some context, and they are created by someone with that intent.” (p. 26) Adaptations are frequently “indigenized” into new cultures. When texts supply images to imageless works, they permanantly change the reader’s experience of the text. For example, due to the films, we now know what a game of Quiddich looks like (and due to the games, we now can know tactics and strategies), or what Tolkien’s orcs look like.


This chapter gives a through account of the way adaptation operates on the different forms of media. Hutcheon does give an in-depth discussion of the different media transformations given by many adaptations, and discusses games in particular. The section is very useful for considering the experiential modes of engagement with adaptations. Hutcheon’s treatment of games focuses on the dimensions of interactivity, kinesthesia, and dependence on the player for the story to reach a happy ending. I think what is missing is a discussion of the mechanics of the narrative worlds in the adapted texts, and how they are transformed into the mechanics of the games. This is what I would consider the content, whereas the structures of interactivity and kinesthesia I think are part of the form of games. As it stands, this discussion is missing, and seems worth considering.


This chapter discusses the reader’s pleasure in adaptation, and here (p. 135) focuses on games and interactive narratives. She discusses these primarily in terms of the media content, for example, sound, visuals, the 3d environments. Again, missing is a discussion of the world or the model underlying the adapted text.

Reading Info:
Author/EditorHutcheon, Linda
TitleA Theory of Adaptation
Tagsfilm, adaptation, specials, narrative
LookupGoogle Scholar, Google Books, Amazon

Adaptation and Media

[General,Research] (03.02.09, 3:03 pm)

Right now I am working on transcribing Linda Hutcheon‘s A Theory of Adaptation. This book has been great. It looks at adaptation as legitimate, universal, and pervasive. It’s great because so much of what I am doing is entrenched in adaptation, and it’s great to see it legitimized. Indeed, adaptations are often viewed very negatively as leeching off of the original media, corrupting it, and mining or wringing it out for money. Just today I came across an article by Alan Moore on some of his current projects, and he discusses the practice of adaptation in very negative terms. Considering his background and experiences, I am not all that surprised, but having read Hutcheon so soon, I spent a little bit of time thinking about exactly what is at stake here.

Moore views adaptation as a corporate practice whose motivation is the capitalist goal of maximizing capital. He doesn’t explain it in exactly those terms, but his perspective is focused on the adaptation producers. The practice of adaptation (in context of his books) frequently involves large special effects budgets, and is reprehensible in his eyes due to the focus on spectacle as opposed to the mastery of media affordances. Essentially, he writes a narrative in comic form because it is best told through comic form. He writes a novel because the story is best told as a novel. Adaptation is pointless to him because it disregards the bond between narrative and medium. To him, the Hollywood film industry is attempting, though the use of its formulas to turn the narratives of his stories into Hollywood narratives. Because form and content are so intertwined, an adaptation that changes medium will necessarily be a change in content, detracting from its original meaning.

I can clearly understand Moore, but I think that it would be fruitful to consider another perspective, which is that of the reader, or the audience, or the consumer. Moore’s outlook is that of the Author, in the Barthes sense. This view is not uncommon, but neglects the role and engagement of the reader. Readers are anxious to make meanings from works, often meanings that the author may have instilled but not stated, or meanings which the author instilled but was not aware of, or meanings that are entirely personal to the readers themselves. Readers do not see the meaning of a work as tied to its medium, or even necessarily its content. When readers take charge, they appropriate and extend and (to borrow Jenkins’ term) poach texts. When a work is introduced to an audience, adaptation is inevitable. This is not to say that Hollywood adaptation is great, but rather some forms of adaptation are inevitable.

It is interesting to compare how Moore describes his own works, as being carefully crafted and interwoven with particular influences, to specifically create commentary on both the original texts and contemporary events. Moore’s collaboration with Kevin O’Neil on The League of Extraordinary Gentlemen is itself interesting as an adapted work because it borrows so many established characters from English literature. It is not an adaptation of another text, but it weaves characters and conventions from other texts to assemble a work. Perhaps because the script itself is original, Moore does not consider it to be an adaptation. When compared with something, such as Jane Austen’s novels, which have themselves spawned an entire textual universe of adaptations, some of which borrow from one specific novel, and others which borrow from multiple, the lines definitely begin to blur.