When i run into problems like this i try to look a the "Different Types" first and then examine the usefulness. In the case of communication i would start by looking at:
- sign language
- text
- verbal
- body language
- music
- etc

then work out their differences. Are any of them more modular than others. That is, do certain types of communication hold methods of communicating that would be more applicable to a computer game?



WE are their,
"Sons of the Free"

LOL Naz, good title

Ok, here''s the deal. You can do a dumbed-down language parser pretty easily. It looks for specific words within the sentance. Words associated with violence would be taken that way, cuss words, too. And certain things could ring the character to speak about them. Like say the character''s on a quest.. and they approach an NPC. They say something like "hi" and the NPC can respond in kind. They say "where is the runestone?" and it could ask what rune etc.. or say something like "i heard it was down in the woods". Simple things like that. punctuation and all that can make it easier to know if the NPC should answer a question or what. It''s something that''s been done. It can''t fully parse, but it can pull out keywords.. which is what our minds do, anyways. How many times can you recall actually hearing someone say the word "the" lol! not many specifically because the word THE holds no meaning, it''s merely a place holder

J

I don't think localisation issues are really a factor, as with any form of advanced parsing techniques, you're getting down into sentence structure, the format of which is fairly constant across most european and western asian languages.

One reason why the old games on the CPC6128 (I had a 464, myself) had fairly impressive parsers and modern games do not, is that the old text adventure games had very limited vocabularies. With perhaps less than 20 verbs and 50 nouns, it was trivial to check the validity of a sentence. Modern games are more likely to have hundreds of nouns, and would most likely want to support more verbs, so the combinations mount up making it much more difficult.

Another benefit of the text adventures were that they nearly all dealt with commands, ie. 'imperative' sentences. These sentences were nearly always of the form 'verb-object[-prepositional object]' which is simple to parse. But to be able to talk to NPCs in the way we would like, we need to be able to understand statements and questions, both of which have different sentence forms. A naive analysis of words in the phrase would not work. Consider this example:

Is it a magical sword
It is a magical sword

The first is a question, the 2nd is a statement, they are identical except for the ordering of the words. Using a question mark helps to make it less ambiguous, but users tend to omit such detail, and when you start adding subordinate clauses in, it becomes even more unmanageable:

Is it a magical sword that can kill dragons?

Parsing these structures is not impossible, but is still something of a nightmare The above sentence is context dependent. Consider the 2 following exchanges:

"Dragons can only be killed by one thing."
"Is it a magical sword that can kill dragons?"
"No, it is the Amulet of BlahBlah."

"What you have there, my son, is DragonBane."
"Is it a magical sword that can kill dragons?"
"Yes, as a matter of fact it is."

2 totally different meanings, for exactly the same sentence. The first is "can dragons be killed by magical swords" and the second is "is this sword a dragon-killing sword". Yet the wording and punctuation is exactly the same. The preceding sentence provides the extra information necessary to impart the semantic meaning. So you must consider conversational context to really understand some sentences.

But my point is this: natural language parsing is easy to do for commands, but very very hard to do for conversations. Although it was a bit limiting, I think the Ultima system where there is a conversation 'tree', with certain NPC sayings revealing new keywords for the player to choose from, is a nice and simple way of encoding a pre-written conversation. It is also non-linear and reduces the amount of wasted conversation if you need to go back and talk again to an NPC to re-hear some important info. I believe Baldur's Gate just has the 'choose the good, evil or neutral response' method, no? Which is even more limiting in my opinion, but perhaps lets you 'play the role' a little better.

I think allowing some limited form of scripting or flag-checking in the conversational engine is a must. At a minimum, the NPC will often need to know if you have completed a quest or something. Other considerations are that NPCs should probably know if you have talked to them before, or if they have seen you around. They could also adjust their conversation based on your reputation, clothing, race/gender/age, etc. Of course, this means that the conversation writer has more work to do, due to more 'branches' on the conversational tree, but that is just another reason to have someone skilled with fiction on your staff, as I'm sure many of you would like to agree with

My MUD will feature fairly advanced (CPC 6128 quality, heh) parsing of the input commands, and an Ultima-like tree system for conversing with NPCs, augmented with an internal markup language to reduce unnecessary branching.

Edited by - Kylotan on July 4, 2000 6:04:57 AM

A fairly simple but cool system was Daggerfall, where

- What you could talk about depended on what you had encountered
- You could choose different tones (vulgar, normal, high-flown)
- Your tone, mixed with your rep, mixed with the class of the other speaker, determined the reaction you''d get.

It worked pretty well.

- me.