[Hajo]

I'm looking for a tutorial on natural language parsers like used in interactive fiction and adventure games.

Can anyone help me? I have some background in parsing programming (context free) languages, but natural languages need another approach, and I'm a bit clueless there beyond scanning for known verbs, objects and subjects ...

I want to use a simple language parser in Sonnheim to let the players interact with the environment in a similar fashion that they do with other player, but writing down what they mean so say and do.

[cowgod]

It just isn't worth it.

If you could get nature language processing to work really well, it would be worth it. But no one anywhere has gotten it to work that well yet.

The only useful recommendation I have is to limit the number of words you can use to a small pool that the player can pick out of a list somewhere. Of course, that would pretty much eliminate the point.

[Hajo]

I doubt I can get it better than in the old adventure games. Some of those companies were working on their parsers for several years overall.

Are there common traps, things that never worked well? I don't have much experience in that field, but if you or someone else could give me some examples what worked well and what didn't, it might help to make up my mind without diving too deep into coding.

[Verious]

Hajo, there are a number of Natural Language Processing (NLP) projects on Sourceforge:

http://sourceforge.net/search/?type_of_search=soft&type_of_search=soft&words=nlp

Perhaps one of them might provide insight into a reasonable solution.

[Hajo]

Thank you :) There seem to be a few interesting projects there.

I have just finished a super-simple prototype which just does pattern matching from words in the input with the names items and beings near the player, and from the players inventory.

It's amazing what it can do already. While it can't really parse language, it is pretty good in figuring what the player wants to do, just by checking what is there and what could be done with that. Drawbacks are that it needs 100% correctly typed input, misspelled item names or verbs are not recognized. Maybe some day I can try fuzzy matching there. Right now I'm very excited about how it's shaping up, but it's too early to say if it will be good enough in the long run.

Maybe I run into problems with that approach, but right now it appears very flexible and even more important "natural" to me than the usual point-and-click mouse control. Maybe with some ideas from the other projects I can improve the parser so much that it survives a real world test.

I wonder a bit if players will accept if the system asks for support if the parser encounters an ambiguous sentance, and prompts the player with a list of possible meanings?

[cowgod]

You can download open source spellchecker code. I used something called Jazzy Spellchecker (written in Java) for one of my programs a long time ago.

I used it to change misspelled words in the input.

[Hajo]

[Verious]

[Mattias Gustavsson]

If you want something like the old adventure games, you might get some ideas from this:

http://www.colossusentertainment.com/Blog/MidwinterRites.html

It's an oldskool style text adventure I made for the TIG forums text-the-halls compo (written in c++, source available)


_________________
www.mattiasgustavsson.com - My blog
www.rivtind.com - My Fantasy world and isometric RPG engine
www.pixieuniversity.com - Software 2D Game Engine

[Hajo]

Cool :) I didn't know you had been participating in the contest, but actually I was too lazy to check it out, just heard about it.

Thanks for the link!

I'm still very uncertain which way to go, but some actions just are beyond the mouses point-and-click abilities.