Abstract: A dialog-exchanging system generating a meaningful and empathetic conversation between  human and a computer is called a chatbot which processes the natural language input that can be either a speech or a textual form and gives the response in the same language and expression as of the human. Various Natural Language Processing (NLP) techniques using the python library, Natural Language Tool Kit (NLTK) these inputs of speech from users can be processed  and intelligent responses from such system engine can be gained to build up a human-like interaction. This paper is a survey on chatbots which have made a significant impact in the previous years about their various development techniques from selected papers which are the witness of remarkable improvements of these chatbots. Also some idea about the advanced scale chatbots such as google now and descendants of Microsoft chatbot is also discussed regarding their popularity and aids in different areas of human life. The paper also discusses the usability or performances of different chatbots along with differences and similarities in techniques through Turing test and Loebner prize.

Keywords: Natural Language Processing, Intelligent Responses, Turing Test, Loebner Prize, AIML

| DOI: 10.17148/IARJSET.2018.596