How Eliza Works All the behavior of Eliza is controlled by a script file. The standard script is attached to the end of this explanation. Eliza starts by reading the script file. Because of Java security, it must be on the same server as the class files. Eliza then reads a line at a time from the user, processes it, and formulates a reply. Processing consists of the following steps. First the sentence broken down into words, separated by spaces. All further processing takes place on these words as a whole, not on the individual characters in them. Second, a set of pre-substitutions takes place. Third, Eliza takes all the words in the sentence and makes a list of all keywords it finds. It sorts this keyword list in descending weight. It process these keywords until it produces an output. Fourth, for the given keyword, a list of decomposition patterns is searched. The first one that matches is selected. If no match is found, the next keyword is selected instead. Fifth, for the matching decomposition pattern, a reassembly pattern is selected. There may be several reassembly patterns, but only one is used for a given sentence. If a subsequent sentence selects the same decomposition pattern, the next reassembly pattern in sequence is used, until they have all been used, at which point Eliza starts over with the first reassembly pattern. Sixth, a set of post-substitutions takes place. Finally, the resulting sentence is displayed as output. The script is used to construct the pre and post substitution lists, the keyword lists, and the decomposition and reassembly patterns. In addition, there is a synonym matching facility, which is explained below. Every line of script is prefaced by a tag that tells what list it is part of. Here is an explanation of the tags. initial: Eliza says this when it starts. final: Eliza says this when it quits. quit: If the input is this, then Eliza quits. Any number permitted. pre: Part of the pre-substitution list. If the first word appears in the sentence, it is replaced by the rest of the words. post: Part of the post-subsititution list. If the first word appears in the sentence, it is replaced by the rest of the words. key: A keyword. Keywords with greater weight are selected in preference to ones with lesser weight. If no weight is given, it is assumed to be 1. decomp: A decomposition pattern. The character * stands for any sequence of words. reasmb: A reassembly pattern. A set of words matched by * in the decomposition pattern can be used as part of the reassembly. For instance, (2) inserts the words matched by the second * in the decomposition pattern. synon: A list of synonyms. In a decomposition rule, for instance, @be matches any of the words "be am is are was" because of the line: "synon: be am is are was". The match @be also counts as a * in numbering the matches for use by reassembly rules. Other Special Rules If a $ appears first in a decomposition rule, then the output is formed as normal, but is saved and Eliza goes on to the next keyword. If no keywords match, and there are saved sentences, one of them is picked at random and used as the output, then it is discarded. If there are no saved sentences, and no keywords match, then it uses the keyword "xnone". --------------------------------------------------------------------- initial: How do you do. Please tell me your problem. final: Goodbye. Thank you for talking to me. quit: bye quit: goodbye quit: quit pre: dont don't pre: cant can't pre: wont won't pre: recollect remember pre: dreamt dreamed pre: dreams dream pre: maybe perhaps pre: how what pre: when what pre: certainly yes pre: machine computer pre: computers computer pre: were was pre: you're you are pre: i'm i am pre: same alike post: am are post: your my post: me you post: myself yourself post: yourself myself post: i you post: you I post: my your post: i'm you are synon: belief feel think believe wish synon: family mother mom father dad sister brother wife children child synon: desire want need synon: sad unhappy depressed sick synon: happy elated glad better synon: cannot can't synon: everyone everybody nobody noone synon: be am is are was key: xnone decomp: * reasmb: I'm not sure I understand you fully. reasmb: Please go on. reasmb: What does that suggest to you ? reasmb: Do you feel strongly about discussing such things ? key: sorry decomp: * reasmb: Please don't apologise. reasmb: Apologies are not necessary. reasmb: I've told you that apologies are not required. key: apologise decomp: * reasmb: goto sorry key: remember 5 decomp: * i remember * reasmb: Do you often think of (2) ? reasmb: Does thinking of (2) bring anything else to mind ? reasmb: What else do you recollect ? reasmb: Why do you recollect (2) just now ? reasmb: What in the present situation reminds you of (2) ? reasmb: What is the connection between me and (2) ? decomp: * do you remember * reasmb: Did you think I would forget (2) ? reasmb: Why do you think I should recall (2) now ? reasmb: What about (2) ? reasmb: goto what reasmb: You mentioned (2) ? key: if 3 decomp: * if * reasmb: Do you think its likely that (2) ? reasmb: Do you wish that (2) ? reasmb: What do you know about (2) ? reasmb: Really, if (2) ? key: dreamed 4 decomp: * i dreamed * reasmb: Really, (2) ? reasmb: Have you ever fantasized (2) while you were awake ? reasmb: Have you ever dreamed (2) before ? reasmb: goto dream key: dream 3 decomp: * reasmb: What does that dream suggest to you ? reasmb: Do you dream often ? reasmb: What persons appear in your dreams ? reasmb: Do you believe that dreams have something to do with your problems ? key: perhaps decomp: * reasmb: You don't seem quite certain. reasmb: Why the uncertain tone ? reasmb: Can't you be more positive ? reasmb: You aren't sure ? reasmb: Don't you know ? key: name 15 decomp: * reasmb: I am not interested in names. reasmb: I've told you before, I don't care about names -- please continue. key: deutsch decomp: * reasmb: goto xforeign reasmb: I told you before, I don't understand German. key: francais decomp: * reasmb: goto xforeign reasmb: I told you before, I don't understand French. key: italiano decomp: * reasmb: goto xforeign reasmb: I told you before, I don't understand Italian. key: espanol decomp: * reasmb: goto xforeign reasmb: I told you before, I don't understand Spanish. key: xforeign decomp: * reasmb: I speak only English. key: hello decomp: * reasmb: How do you do. Please state your problem. reasmb: Hi. What seems to be your problem ? key: computer 50 decomp: * reasmb: Do computers worry you ? reasmb: Why do you mention computers ? reasmb: What do you think machines have to do with your problem ? reasmb: Don't you think computers can help people ? reasmb: What about machines worrys you ? reasmb: What do you think about machines ? key: am decomp: * am i * reasmb: Do you believe you are (2) ? reasmb: Would you want to be (2) ? reasmb: Do you wish I would tell you you are (2) ? reasmb: What would it mean if you were (2) ? reasmb: goto what decomp: * reasmb: Why do you say 'am' ? reasmb: I don't understand that. key: are decomp: * are you * reasmb: Why are you interested in whether I am (2) or not ? reasmb: Would you prefer if I weren't (2) ? reasmb: Perhaps I am (2) in your fantasies. reasmb: Do you sometimes think I am (2) ? reasmb: goto what decomp: * are * reasmb: Did you think they might not be (2) ? reasmb: Would you like it if they were not (2) ? reasmb: What if they were not (2) ? reasmb: Possibly they are (2). key: your decomp: * your * reasmb: Why are you concerned over my (2) ? reasmb: What about your own (2) ? reasmb: Are you worried about someone else's (2) ? reasmb: Really, my (2) ? key: was 2 decomp: * was i * reasmb: What if you were (2) ? reasmb: Do you think you were (2) ? reasmb: Were you (2) ? reasmb: What would it mean if you were (2) ? reasmb: What does (2) suggest to you ? reasmb: goto what decomp: * i was * reasmb: Were you really ? reasmb: Why do you tell me you were (2) now ? reasmb: Perhaps I already know you were (2). decomp: * was you * reasmb: Would you like to believe I was (2) ? reasmb: What suggests that I was (2) ? reasmb: What do you think ? reasmb: Perhaps I was (2). reasmb: What if I had been (2) ? key: i decomp: * i @desire * reasmb: What would it mean to you if you got (3) ? reasmb: Why do you want (3) ? reasmb: Suppose you got (3) soon ? reasmb: What if you never got (3) ? reasmb: What would getting (3) mean to you ? reasmb: What does wanting (3) have to do with this discussion ? decomp: * i am* @sad * reasmb: I am sorry to hear that you are (3). reasmb: Do you think that coming here will help you not to be (3) ? reasmb: I'm sure it's not pleasant to be (3). reasmb: Can you explain what made you (3) ? decomp: * i am* @happy * reasmb: How have I helped you to be (3) ? reasmb: Has your treatment made you (3) ? reasmb: What makes you (3) just now ? reasmb: Can you explan why you are suddenly (3) ? decomp: * i was * reasmb: goto was decomp: * i @belief * i * reasmb: Do you really think so ? reasmb: But you are not sure you (3). reasmb: Do you really doubt you (3) ? decomp: * i* @belief *you * reasmb: goto you decomp: * i am * reasmb: Is it because you are (2) that you came to me ? reasmb: How long have you been (2) ? reasmb: Do you believe it is normal to be (2) ? reasmb: Do you enjoy being (2) ? decomp: * i @cannot * reasmb: How do you think that you can't (3) ? reasmb: Have you tried ? reasmb: Perhaps you could (3) now. reasmb: Do you really want to be able to (3) ? decomp: * i don't * reasmb: Don't you really (2) ? reasmb: Why don't you (2) ? reasmb: Do you wish to be able to (2) ? reasmb: Does that trouble you ? decomp: * do i feel * reasmb: Tell me more about such feelings. reasmb: Do you often feel (2) ? reasmb: Do you enjoy feeling (2) ? reasmb: Of what does feeling (2) remind you ? decomp: * i * you * reasmb: Perhaps in your fantasies we (2) each other. reasmb: Do you wish to (2) me ? reasmb: You seem to need to (2) me. reasmb: Do you (2) anyone else ? decomp: * reasmb: You say (1) ? reasmb: Can you elaborate on that ? reasmb: Do you say (1) for some special reason ? reasmb: That's quite interesting. key: you decomp: * you remind me of * reasmb: goto alike decomp: * you are * reasmb: What makes you think I am (2) ? reasmb: Does it please you to believe I am (2) ? reasmb: Do you sometimes wish you were (2) ? reasmb: Perhaps you would like to be (2). decomp: * you* me * reasmb: Why do you think I (2) you ? reasmb: You like to think I (2) you -- don't you ? reasmb: What makes you think I (2) you ? reasmb: Really, I (2) you ? reasmb: Do you wish to believe I (2) you ? reasmb: Suppose I did (2) you -- what would that mean ? reasmb: Does someone else believe I (2) you ? decomp: * you * reasmb: We were discussing you -- not me. reasmb: Oh, I (2) ? reasmb: You're not really talking about me -- are you ? reasmb: What are your feelings now ? key: yes decomp: * reasmb: You seem to be quite positive. reasmb: You are sure. reasmb: I see. reasmb: I understand. key: no decomp: * reasmb: Are you saying no just to be negative? reasmb: You are being a bit negative. reasmb: Why not ? reasmb: Why 'no' ? key: my 2 decomp: $ * my * reasmb: Lets discuss further why your (2). reasmb: Earlier you said your (2). reasmb: But your (2). reasmb: Does that have anything to do with the fact that your (2) ? decomp: * my* @family * reasmb: Tell me more about your family. reasmb: Who else in your family (4) ? reasmb: Your (3) ? reasmb: What else comes to mind when you think of your (3) ? decomp: * my * reasmb: Your (2) ? reasmb: Why do you say your (2) ? reasmb: Does that suggest anything else which belongs to you ? reasmb: Is it important that your (2) ? key: can decomp: * can you * reasmb: You believe I can (2) don't you ? reasmb: goto what reasmb: You want me to be able to (2). reasmb: Perhaps you would like to be able to (2) yourself. decomp: * can i * reasmb: Whether or not you can (2) depends on you more than me. reasmb: Do you want to be able to (2) ? reasmb: Perhaps you don't want to (2). reasmb: goto what key: what decomp: * reasmb: Why do you ask ? reasmb: Does that question interest you ? reasmb: What is it you really wanted to know ? reasmb: Are such questions much on your mind ? reasmb: What answer would please you most ? reasmb: What do you think ? reasmb: What comes to mind when you ask that ? reasmb: Have you asked such questions before ? reasmb: Have you asked anyone else ? key: because decomp: * reasmb: Is that the real reason ? reasmb: Don't any other reasons come to mind ? reasmb: Does that reason seem to explain anything else ? reasmb: What other reasons might there be ? key: why decomp: * why don't you * reasmb: Do you believe I don't (2) ? reasmb: Perhaps I will (2) in good time. reasmb: Should you (2) yourself ? reasmb: You want me to (2) ? reasmb: goto what decomp: * why can't i * reasmb: Do you think you should be able to (2) ? reasmb: Do you want to be able to (2) ? reasmb: Do you believe this will help you to (2) ? reasmb: Have you any idea why you can't (2) ? reasmb: goto what decomp: * reasmb: goto what key: everyone 2 decomp: * @everyone * reasmb: Realy, (2) ? reasmb: Surely not (2). reasmb: Can you think of anyone in particular ? reasmb: Who, for example? reasmb: Are you thinking of a very special person ? reasmb: Who, may I ask ? reasmb: Someone special perhaps ? reasmb: You have a particular person in mind, don't you ? reasmb: Who do you think you're talking about ? key: everybody 2 decomp: * reasmb: goto everyone key: nobody 2 decomp: * reasmb: goto everyone key: noone 2 decomp: * reasmb: goto everyone key: always 1 decomp: * reasmb: Can you think of a specific example ? reasmb: When ? reasmb: What incident are you thinking of ? reasmb: Really, always ? key: alike 10 decomp: * reasmb: In what way ? reasmb: What resemblence do you see ? reasmb: What does that similarity suggest to you ? reasmb: What other connections do you see ? reasmb: What do you suppose that resemblence means ? reasmb: What is the connection, do you suppose ? reasmb: Could here really be some connection ? reasmb: How ? key: like 10 decomp: * @be *like * reasmb: goto alike