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Show HN: Natural Language Processing Demystified

286 points by mothcamp ↗ HN
Link: https://www.nlpdemystified.org/

Hi HN:

After a year of work, I've published my free NLP course. The course helps anyone who knows Python and a bit of math go from the basics to today's mainstream models and frameworks.

I strive to balance theory and practice, so every module consists of detailed explanations and slides along with a Colab notebook putting the ideas into practice (in most modules).

The notebooks cover how to accomplish everyday NLP tasks including extracting key information, document search, text similarity, text classification, finding topics in documents, summarization, translation, generating text, and question answering.

The course is divided into two parts. In part one, we cover text preprocessing, how to turn text into numbers, and multiple ways to classify and search text using "classical" approaches. And along the way, we'll pick up valuable bits on how to use tools such as spaCy and scikit-learn.

In part two, we dive into deep learning for NLP. We start with neural network fundamentals and go through embeddings and sequence models until we arrive at transformers and the mainstream models of today.

No registration required: https://www.nlpdemystified.org/

38 comments

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reichardt
I love your course for being very comprehensive and technical while not getting lost in mundane details. Like the opposite of the following quote:

“I didn't have time to write a short letter, so I wrote a long one instead.” [1]

[1] https://www.goodreads.com/quotes/21422-i-didn-t-have-time-to...

mothcamp
Really appreciate that. Finding that balance was one of the hardest parts of building this course.
reichardt
Yes, it's easy to see you put a lot of thought into that. I hope your course receives much more exposure. When I first found your videos a few weeks ago, I was surprised how few views they have given to the quality of the course.

Do you record the voice track of your videos yourself?

Glad to see you published the final lesson about transformers. Was looking forward to that!

mothcamp
I did record all voice tracks, yeah. If I do this again, I'll probably use a lot of generative tools now. :-D

Hope you find the transformers module useful!

reichardt
That's impressive. The audio track of your videos is so clean and well understandable that I was wondering if you used a studio setup or voice synthesis software. Well done!
mharig
"Je n’ai fait celle-ci plus longue que parce que je n’ai pas eu le loisir de la faire plus courte."

Blaise Pascal, 1656

FYI

reichardt
Ah, thanks! I didn’t know that and shouldn’t have used the first result that came up with a google search.
yupis
I wish there where written notes to study. Anyways great video.
wazoox
This looks awesome. No signup, that's a dream :)
brooksbp
Thank you for sharing this! I am currently studying NLP..

Along the way, I've been struggling with a question and I hope someone can help me understand how to go about this: how would you build a model that does more than one NLP task? For a simple classifier like input: text (a tweet) and output: text (an emotion), you can fine-tune an existing classifier on such a data set. But, how would you build a model that does NER and sentiment analysis? E.g. input: text (a Yelp review of a restaurant) and output: list of (entity, sentiment) tuples (e.g. [("tacos", "good"), ("margaritas", "good"), ("salsa", "bad")]). If you have a data set structured this way, and want to fine-tune a model, how does that model know how to make use of a Python list of tuples?

mothcamp
You could start by looking into either multitask transformers or really general seq2seq models like T5. With T5, for example, it just learns to transform one text sequence into another. So you could fine-tune T5 to produce your target sequence, but rather than outputting an explicit Python list of tuples, it would output a string that looks like a sequence of tuples.

Or maybe skip all that and outsource it to GPT: https://imgur.com/a/BQv6C3K

brooksbp
Ah, so if the model is just converting input text into output text, it can really learn how to do just about anything? But, there may be certain aspects of model design that make it better at some types of conversions ("tasks") than others? And there may be certain data sets that you want to train a base model on to get base learning of such as general language comprehension, and then build on top of that for your specific use case?
mothcamp
Yeah, I can see that being the case for specialized domains. With state-of-the-art models widely available to the public, knowledge of the domain and its workflows, and fine-tuning models to suit the domain will probably be your edge.
trenchgun
It is kind of like a very opaque but trainable Turing machine.
axiom92
If you have the dataset, you can try to train a model like T5 [1], notebook [2].

You just need to create [(input, output)] examples in the format you want.

For example

[(a Yelp review of a restaurant, [("tacos", "good"), ("margaritas", "good"), ("salsa", "bad")]].

With enough data, the model should be able to learn to generate the output in the right format.

> Python list of tuples

Things get interesting if you want to generate actual Python code. You can use a large language model with just a few examples of the task to generate such code. For example, see https://reasonwithpal.com/.

Happy to answer more questions!

[1] https://huggingface.co/docs/transformers/model_doc/t5

[2] https://colab.research.google.com/github/huggingface/noteboo...

gattilorenz
Yours is an example of aspect-based sentiment analysis. Typically it has been tackled in two steps: first extract the aspects, then classify them as positive/negative. GPT or T5 are possible options for doing both in one go, but splitting the task seems to be still a good option [1].

[1] http://essay.utwente.nl/91778/1/Middelraad_BA_EEMCS.pdf

strumyktomira
Oh! That interesting me a lot :) I wanted to learn it in next months. Thank You very much! :)
yannis
Thanks excellent course, watched about an hour or two. Very well made. Deserves more exposure.
clueless
thank you. Free ytube videos, with link to google colabs, , this is incredible...
echobear
thank you!! as a CS student interested in ML I will 100% be taking a look at this when I get some free time
account-5
I like that your site runs properly with only first party scripts enabled in ublock, very rare these days.

Secondly kudos for not requiring a sign up and for making it free!

Looks like a brilliant resource, thank you.

posharma
Who is the intended audience for this course? Is it application developers looking to use NLP in their apps? Or machine/deep learning devs?
mothcamp
It's for anyone who wants to learn NLP such that they get (a) an understanding of what's going on under the hood and (b) knowledge of how to get stuff done.

So the ideal outcome is someone who gets an end-to-end view from theory/concept to implementation.

If someone just wants to learn how to use tools/frameworks, I'd stick to the Colab notebooks. If someone's already experienced in ML and wants to learn something NLP-specific, I'd skip around to see what's interesting.

santiagobasulto
Great content! And thank you for making it open and free. I recommend adding a License to your Github repo.
benjismith
This is awesome! I just finished watching the Unit 10 video ("Neural Networks I") and it filled in quite a few gaps in my understanding.

I really love that you build a complete working example, all the way down to the matrix multiplications, so that we can see how everything works, at every layer of abstraction.

I'm looking forward to the next unit, and I can already tell this is going to be an indispensable reference I'll come back to review again and again.

Thank you!!

phodo
Thank you for this. Did you use any tool to publish the site and UI, or all static and vanilla? It's snappy, nice and clean.
mothcamp
Thanks. It's all statically-generated pages with NextJS and Tailwind.
escanor
great work! just a note regarding tf-idf, when you mention log10: i think you're missing the point on the reason of log and most importantly base 10. namely, using log10 gives us a perspective on the number of digits of the term/document frequency. if a term "A" occurs 23 times and a term "B" occurs 50, they will have a very close representation (because both numbers are 2 digits ones).

anyway, thanks for the submission