Automated Spelling Correction – The Basics of How it Works

In this post, I am going to talk about automated spelling correction. Let’s say you are writing a document on your computer, and instead of typing “morning”, you accidentally type “mornig”. If you have automated spelling correction enabled, you will probably see that “mornig” has been transformed to “morning” on its own. How does this work? How does your computer know that when you typed “mornig”, you actually meant “morning”? We are going to see how in this post.

Spelling mistakes could turn out to be real words!

Before we actually go through how spelling correction works, let’s think about the complexity of this problem. In the previous example, “mornig” was not a real word, so we knew it had to be a spelling mistake. But what if you misspelled “college” as “collage”, or you misspelled “three” as “tree”? In these cases, the word you typed incorrectly happens to be an actual word itself! Correcting these types of errors is called real word spelling correction. On the other hand, if the error is not a real word (like “mornig” instead of “morning”), correcting those errors is called non-word spelling correction. You can see that real world spelling correction seems more difficult than non-word spelling correction because every word that you type could be an error (even if it has a correct spelling). For example, the sentence “The tree threes were tail” makes no sense because every word except “the” and “were” is an error even though they are all actual words. The actual sentence should be “The three trees were tall”. In this post, I am going to talk about non-word spelling correction with a basic approach to it.

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Chatbots to Drive Student Engagement in Higher Education

Whether you are ready for chatbots or not, they have been the future we live in now. Chatbots are not robots, but they are supposed to mimic humans. They are a piece of software that you chat with to get things done or be entertained. You have probably used Apple’s Siri, Google Assistant or Microsoft’s Cortana. But chatbots are more than just the built-in personal assistants. They are everywhere now; from ordering pizza to checking flight status

I have run an experiment to use chatbots in higher education in order to drive student engagement beyond the classroom experience. In this post, I am going to share my experience in developing a chatbot teaching assistant, called Koko. Continue reading

An Introduction to N-grams: What Are They and Why Do We Need Them?

In this post I am going to talk about N-grams, a concept found in Natural Language Processing ( aka NLP). First of all, let’s see what the term ‘N-gram’ means. Turns out that is the simplest bit, an N-gram is simply a sequence of N words. For instance, let us take a look at the following examples.

  1. San Francisco (is a 2-gram)
  2. The Three Musketeers (is a 3-gram)
  3. She stood up slowly (is a 4-gram)

Now which of these three N-grams have you seen quite frequently? Probably, “San Francisco” and “The Three Musketeers”. On the other hand, you might not have seen “She stood up slowly” that frequently. Basically, “She stood up slowly” is an example of an N-gram that does not occur as often in sentences as Examples 1 and 2.

Now if we assign a probability to the occurrence of an N-gram or the probability of a word occurring next in a sequence of words, it can be very useful. Why? Continue reading

Build your own Natural Language Processing based Intelligent Assistant using Python, It’s easy!

Before we begin, let us talk about how Mike (a fictional character) spends a typical morning. Mike begins his day by searching for breakfast recipes on Google Now ( After a filling breakfast, Mike starts getting ready for work. He asks Siri ( to tell him the weather and traffic conditions for his drive to work. Finally, as Mike gets ready to leave the house, he asks Alexa ( to dim the lights and thermostat. It is not even 10 a.m. yet, but Mike like many of us has already used three intelligent personal assistant applications using Natural Language Processing (NLP). We will unravel the mysteries of building intelligent personal assistants with a simple example to build such an assistant quite easily using NLP.

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$500 prize money at the ACM SIGAI Student Essay Contest on the Responsible Use of AI Technologies! Apply now!

  1. Do you have an opinion on the responsible use of AI technologies?
  2. Do you want to win one of several $500 cash prizes?
  3. Do you want to talk one-on-one (via skype) to one of the following AI researchers:
  • Murray Campbell (Senior Manager, IBM Thomas J. Watson Research Center)
  • Eric Horvitz (Managing Director, Microsoft Research)
  • Peter Norvig (Director of Research, Google)
  • Stuart Russell (Professor, University of California at Berkeley) or
  • Michael Wooldridge (Head of the CS Department, University of Oxford)?

Read on!

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