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ChatterbotA chatterbot (also chatbot, chatterbox) is a bot program which attempts to maintain a conversation with a person. While it is true that a good understanding of a conversation is required to carry on a meaningful dialog, most chatterbots do not attempt this. Instead they attempt to pick up cue words or phrases from the person which will allow them to use pre-prepared or pre-calculated responses which can move the conversation on in an apparently meaningful way without requiring them to know what they are talking about. One exception to this approach is Jabberwacky which attempts to model the way humans learn new facts and language. The classic early chatterbots are ELIZA and PARRY. More recent programs are Racter and A.L.I.C.E.. A collection of games and functional features accessed via natural language processing allows ELLA to further extend the potential of chatterbots. WikiChat -- a simple Chatterbot example In principle a chatterbot can be a very short program. For instance the following QBASIC programwhich should be copied and saved as WikiChat.BASimplements a chatterbot which will learn phrases in any language by repetition in much the same way that a parrot does. WikiChat: DEFINT A-Z GOSUB Initialise GOSUB LoadData GOSUB Converse GOSUB StoreData SYSTEM Initialise: LET DictionarySize = 1000 DIM Context$(DictionarySize) DIM Alternatives$(DictionarySize) LET EmptyRow = 0 LET EndOfResponseCharacter$ = CHR$(180) LET ContextLength = 6 LET CurrentContext$ = STRING$(ContextLength, EndOfResponseCharacter$) LET DictionaryFile$ = "WIKICHAT.MEM" RANDOMIZE TIMER RETURN Converse: DO LINE INPUT "Human: "; Response$ IF Response$ = "" THEN EXIT DO LET Response$ = Response$ + EndOfResponseCharacter$ GOSUB Analyse LET Response$ = "" GOSUB Generate PRINT "Computer: "; Response$ LOOP RETURN Analyse: DO WHILE Response$ > "" LET CurrentCharacter$ = LEFT$(Response$, 1) LET Response$ = MID$(Response$, 2) GOSUB InsertCharacter LET CurrentContext$ = MID$(CurrentContext$, 2) + CurrentCharacter$ LOOP RETURN Generate: DO GOSUB Lookup LET CurrentCharacter$ = MID$(Alternatives$(DictionaryIndex), INT(RND * LEN(Alternatives$(DictionaryIndex))) + 1, 1) IF CurrentCharacter$ = "" THEN EXIT DO ELSE LET CurrentContext$ = MID$(CurrentContext$, 2) + CurrentCharacter$ IF CurrentCharacter$ = EndOfResponseCharacter$ THEN EXIT DO ELSE LET Response$ = Response$ + CurrentCharacter$ END IF END IF LOOP RETURN InsertCharacter: GOSUB Lookup IF INSTR(Alternatives$(DictionaryIndex), CurrentCharacter$) = 0 THEN LET Alternatives$(DictionaryIndex) = Alternatives$(DictionaryIndex) + CurrentCharacter$ END IF RETURN Lookup: LET Context$(EmptyRow) = CurrentContext$ LET DictionaryIndex = 0 DO WHILE CurrentContext$ <> Context$(DictionaryIndex) LET DictionaryIndex = DictionaryIndex + 1 LOOP IF DictionaryIndex = EmptyRow AND DictionaryIndex < DictionarySize THEN LET Alternatives$(EmptyRow) = "" LET EmptyRow = DictionaryIndex + 1 END IF RETURN LoadData: OPEN DictionaryFile$ FOR APPEND AS #1 CLOSE #1 OPEN DictionaryFile$ FOR INPUT AS #1 DO WHILE EmptyRow < DictionarySize AND NOT EOF(1) LINE INPUT #1, Context$(EmptyRow) LINE INPUT #1, Alternatives$(EmptyRow) LET EmptyRow = EmptyRow + 1 LOOP CLOSE #1 RETURN StoreData: OPEN DictionaryFile$ FOR OUTPUT AS #1 FOR DictionaryIndex = 0 TO EmptyRow - 1 PRINT #1, Context$(DictionaryIndex) PRINT #1, Alternatives$(DictionaryIndex) NEXT CLOSE #1 RETURN Note that to begin with, this chatterbot knows nothing and therefore says nothing. However if one uses simple conversation with it, like a parrot it will begin to reply as it starts to find responses that are appropriate for the immediately preceding sentence. WikiChat learning sessions The following sessions show how to teach WikiChat some simple conversation. Note that sessions are started by running the WikiChat program and ended by pressing the return key without giving a response to the computer. They show WikiChat being taught a basic conversational pattern in English. (Session 1) Human: hello there Computer: Human: hello Computer: Human: how are you Computer: Human: fine thanks how are you Computer: fine thanks how are you Human: fine thanks Computer: Human: (Session 2) Human: hello Computer: how are you Human: fine thanks how are you Computer: fine thanks Human: glad to hear it Computer: Human: (Session 3) Human: hello Computer: how are you Human: fine thanks Computer: glad to hear it Human: The responses will be stored for the next session, so that there is no need to reteach them but it should be noted that while this example chatterbot will create "original" sentences after a little teaching, it has a very limited capacity and works best with short sentences. See also External links - Commercial bots
- Create your own bots
- Self learning bots
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