International Journal of Machine Learning and Computing, Vol. 9, No. 4, August 2019 Correcting Typographical Error and Understanding User Intention in Chatbot by Combining N-Gram and Machine Learning Using Schema Matching Technique Mikael L. Tedjopranoto, Andreas Wijaya, Levi Hanny Santoso, and Derwin Suhartono assistants in the form of chatbot by Apple and Windows [2]. Abstract—Purpose of this research is to make chatbot based Using chatbot, people can easily send any information to their system to help Small and Medium Enterprise business. Initially, customers by creating some defined conversations. So, we build this application only to help Small and Medium chatbots can be so convenient and easy to use. Enterprise owner to monitor their business and report. Yet, we realize that we can make our chatbot to be more effective and The problem that business owner faced these days, is they efficient using machine learning technique. N-gram and machine need to come to their store to check their income, employees, learning using schema matching are embedded to the chatbot to and their stock. With chatbot, those things are not necessary understand user intention and correct typographical error anymore, business owner only needs to send a message to inside the sentences. Finally, the chatbot has been successfully Business Bot, to do all of those things. achieved those objectives. It can be concluded that the chatbot Chatbot is our future, however, people in Indonesia is not can drive the users’ feeling to be more convenient and help Small and Medium Enterprise owner to monitor their business. used to asking questions or do their daily basis using chatbot. Our idea is to introduce or SME (Small Medium Enterprise) Index Terms—Chatbot, n-gram, machine learning, schema to chatbot, so they can manage their business as easy as matching, typographical error, user intention. sending a chat message. To make it more convenient and easy to use, we will attempt to develop a chatbot using machine learning. Machine I. INTRODUCTION learning is a subfield of Artificial Intelligence that gives the There are no doubts that the digital era is developing machine the capabilities to learn from data. Using machine quickly, with different platform reaching the users such as learning algorithm, we aim to produce a model that will social media, email, and websites. We have a lot of ways of correct the typo of users and understand user’s intent without communication, the process of sending messages to become typing the exact keyword.Typo itself is, Typing errors occurs more and more interactive than it used to be. In the last few when the typist or the author knows the actual and correct years, digital communication was about social media and spelling of the word but mistakenly or by slip of finger presses information technology is influencing everything. an invalid key [3]. User intent is the identification and In the recent years, several emerging issues are posing categorization of what a user intended or wanted when they serious challenges to the small and medium-sized enterprises typed their search terms [4]. To correct the typo, we will use (SME's). These enterprises enter the new era, and one N-gram technique. An N-gram is an N-character slice of a challenge that worth to be addressed is globalization. Small longer string, N-gram-based matching has had some success medium enterprises also need to adapt to globalization, one in dealing with ASCII. If we count N-grams that are common way to do that is to digitalize their business with information to two strings, we get a measure of their similarity that is technology. resistant to a wide variety of textual errors [5]. In our system, As we can see, the role of IT is very big in small medium we use N-grams of several different lengths simultaneously enterprises, 45% said that it is a necessary cost, the other 35% and compare the results of the N-gram to correct the typo. The said that it is an enabler of business efficiency and the rest said user will have chatting experience such that it looks like doing it is a driver of competitive advantage or differentiation. In chat with real person. this research, we want to propose chatbot as a tool to help Based on the introduction, we identify some problems, small medium enterprises in Indonesia. Chatbot is a computer does this application help owner of Small Medium Enterprise? program that has the ability to hold a conversation with a does the user feel more convenient with our application using human using Natural Language Speech [1]. Basically, chatbot Artificial Intelligence technique? are the evaluations for the has an ability to send text messages and it feels like a human technique good enough to satisfy the user? We hypothesize who sends it. These days people might be using these daily that by implementing artificial intelligence technique, such as needs, for example, Siri and Cortana are intelligent personal N-gram and machine learning will help the chatbot become convenient and easy to use. The objectives of this research are: (1) to succeed in Manuscript received October 22, 2018; revised April 15, 2019. This work correcting the typo from the user's input based on our pre-set was supported by Bina Nusantara University. The authors are with Computer Science Department, School of Computer keywords, (2) to implement machine learning to define the Science, Bina Nusantara University, Jakarta, Indonesia 11480 (e-mail: user's intent after the user types something, and (3) to create [email protected], [email protected], an application that can help Small Medium Enterprises owner [email protected], [email protected]). doi: 10.18178/ijmlc.2019.9.4.828 471 International Journal of Machine Learning and Computing, Vol. 9, No. 4, August 2019 retrieves information about their business. The benefits of this II. METHOD COMPARISON research are: (1) trained machine learning architecture can be SuperAgent is a powerful customer service chatbot used for another similar chatbot, and (2) Small Medium leveraging large-scale and publicly available e-commerce Enterprises owner can use this application to monitor their data. Nowadays, large e-commerce websites contain a great business. of in-page product descriptions as well as user-generated content, such as Amazon.com, Ebay.com and many others. Take an Amazon.com product page as an example, which contains detail Product Information (PI), a set of existing customer Questions & Answers (QA), as well as sufficient Customer Reviews (CR). This crowd-sourcing style of data provides appropriate information to feed into chat engines, accompanying human support staff to deliver better customer service experience when online shopping [8]. Fig. 2 shows the system overview of SuperAgent. As the figure shows, when the product page is visited, SuperAgent crawls the HTML information and scrapes PI+QA+CR data from the webpage. Given an input query from a customer, different engines are processed in parallel. If one of the Fig. 1. SMEs survey of IT services (IDC, 2017). answers from the first three engines has high confidence, the For objective evaluation, we provide N-gram score table chatbot will return the answer as response. Otherwise, the for every related keyword and the accuracy of the output. For chit-chat engine will generate a reply from the predefined schema matching, we provide top five of our users’ input and permitted response sets. count the accuracy, precision, recall and F1 score. They are calculated based on True Positive (TP), True Negative (TN), False Positive (FP) and False Negative (FN). True positive is number of correctly predicted data as positive values which means the value of actual class is “Yes” and the value of predicted class is also “Yes”. True negative is number of correctly predicted data as negative values which means that the value of actual class is “No” and value of predicted class is also “No”. False positive is “No” for actual class and “Yes” Fig. 2. The system overview of SuperAgent. for predicted class. False negative is “Yes” for actual class but “No” for predicted class. Accuracy is simply the ratio of SuperAgent uses regression forest model to choose correctly predicted observations, it is the number of correct between their techniques while our chatbot will automatically prediction divided by total number of prediction [6]. Recall is use between n-gram or schema matching technique after the number of retrieved relevant items as a proportion of all knowing the users’ intention. N-gram is “an n-token sequence relevant items. Therefore, recall is a measure of effectiveness of words” [9]. N-grams originate from the field of in retrieving performance and can be viewed as a measure of computational linguistics. Schema matching refers to problem effectiveness in including relevant items in the retrieved set. of finding similarity between elements of different database Precision is the number of retrieved relevant items as a schemas. Schema matching uses machine learning techniques proportion of the number of retrieved items. Precision is, to find the correct equivalence between the input schemas therefore, a measure of purity in retrieval performance, a [10]. For the training system, we use K-Nearest Neighbor measure of effectiveness in excluding non-relevant items (KNN). KNN algorithm is a method for classifying objects from the retrieved set. The F1 score is the weighted average of based on closest training examples in the feature space [11]. precision and recall. Therefore, this score takes both false positives and false negatives into account. It works best if false positives and false negatives have similar cost [7]. III. RESEARCH METHODOLOGY This research writing systematics is divided into 5 chapters.