This is where the user and computer attempt to perform operations through a subset of spoken language. For example to create a folder the user might say"New folder" rather than "MD". Note -MD is the DOS command to create a folder.

Natural language is also used to interact with special software. There is a area of research which is trying to design more and more complicated interfaces using natural language. An interesting aside is the phenomenon of the chat bot. This is a program which attempts to "chat" with a user. What the program is doing is analyzing natural language and trying to respond correctly to what the user said.

Look at http://www.alicebot.org/ for an example chat bot.

A lot of problems arise when using a natural language interface. The most specific one is the simply fact that language is ambiguous. When dealing with a natural language interface we assume a level of intelligence on the part of the computer. If the computer does not have sufficient knowledge of the language, of the current context, of the tasks to perform and even of the person talking there will be ambiguity. As such natural language interfaces tend to be very specific and will only allow a subset of a languages vocabulary. Consider all the ways we can say yes and no. The amount of permutations on how humans speak means that it is an almost impossible task to develop interface which allows the full language.

Main features

• Allows humans to use there own language to communicate with the computer.
• Will require very little understanding of system
• Short learning curve to use the system
• Will only use a small section of the vocabulary
• These systems can be easily tricked (have a chat with A.L.I.C.E to see this point)