I'm a newbie in the field of Machine Learning and Supervised learning.
My task is the following: from the name of a movie file on a disk, I'd like to retrieve some metadata about the file. I have no control on how the file is named, but it has a title and one or more additional info, like a release year, a resolution, actor names and so on.
Currently I have developed a rule heuristic-based system, where I split the name into tokens and try to understand what each word could represent, either alone or with adjacent ones. For detecting people names for example, I'm using a dataset of english names, and score the word as being a potential person's name if I find it in the dataset. If adjacent to it is a word that I scored as a potential surname, I score the two words as being an actor. And so on. It works with a decent accuracy, but changing heuristic scores manually to "teach" the system is tedious and unpredictable.
Such a rule-based system is hard to maintain or develop further, so, out of curiosity, I was exploring the field of machine learning. What I would like to know is:
Is there some kind of public literature about these kinds of problems?
Is ML a good way to approach the problem, given the limited data set available?
How would I proceed to debug or try to understand the results of such a machine? I already have problems with the "simplistic" heuristic engine I have developed..
Thanks, any advice would be appreciated.
You need to look into NLP (natural language processing). NLP deals with text processing and other things; for example entity recognition and tagging.
Here is an example of using Spacy library: https://spacy.io/usage/linguistic-features.
Some time ago I did a similar thing, you can see it here: https://github.com/Erlemar/Erlemar.github.io/blob/master/Notebooks/Fate_Zero_explore.ipynb
Related
I'm new to the ML/NLP field so my question is what technology would be most appropriate to achieve the following goal:
We have a short sentence - "Where to go for dinner?" or "What's your favorite bar?" or "What's your favorite cheap bar?"
Is there a technology that would enable me to train it providing the following data sets:
"Where to go for dinner?" -> Dinner
"What's your favorite bar?" -> Bar
"What's your favorite cheap restaurant?" -> Cheap, Restaurant
so that next time we have a similar question about an unknown activity, say, "What is your favorite expensive [whatever]" it would be able to extract "expensive" and [whatever]?
The goal is if we can train it with hundreds of variations(or thousands) of the question asked and relevant output data expected, so that it can work with everyday language.
I know how to make it even without NLP/ML if we have a dictionary of expected terms like Bar, Restaurant, Pool, etc., but we also want it to work with unknown terms.
I've seen examples with Rake and Scikit-learn for classification of "things", but I'm not sure how would I feed text into those and all those examples had predefined outputs for training.
I've also tried Google's NLP API, Amazon Lex and Wit to see how good they are at extracting entities, but the results are disappointing to say the least.
Reading about summarization techniques, I'm left with the impression it won't work with small, single-sentence texts, so I haven't delved into it.
As #polm23 mentioned for simple stuff you can use the POS tagging to do the extraction. The services you mentioned like LUIS, Dialog flow etc. , uses what is called Natural Language Understanding. They make uses of intents & entities(detailed explanation with examples you can find here). If you are concerned that your data is going online or sometimes you have to go offline, you always go for RASA.
Things you can do with RASA:
Entity extraction and sentence classification. Mention which particular term to be extracted from the sentence by tagging the word position with a variety of sentence. So if any different word comes other than what you had given in the training set it will be detected.
Uses rule-based learning and also keras LSTM for detection.
One downside when comparing with the online services is that you have to manually tag the position numbers in the JSON file for training as opposed to the click and tag features in the online services.
You can find the tutorial here.
I am having pain in my leg.
Eg I have trained RASA with a variety of sentences for identifying body part and symptom (I have limited to 2 entities only, you can add more), then when an unknown sentence (like the one above) appears it will correctly identify "pain" as "symptom" and "leg" as "body part".
Hope this answers your question!
Since "hundreds to thousands" sound like you have very little data for training a model from scratch. You might want to consider training (technically fine-tuning) a DialogFlow Agent to match sentences ("Where to go for dinner?") to intents ("Dinner"), then integrating via API calls.
Alternatively, you can invest time in fine-tuning a small pre-trained model like "Distilled BERT classifier" from "HuggingFace" as you won't need the 100s of thousands to billions of data samples required to train a production-worthy model. This can also be assessed offline and will equip you to solve other NLP problems in the future without much low-level understanding of the underlying statistics.
I'm learning Machine Learning with Tensorflow. I've work with some dataset like Iris flower data and Boston House, but all those data's values was float.
Yes I'm looking for a dataset that contain data's values are in string format to practice. Can you give me some suggestions?
Thanks
I provide you just two easy-to-start places:
Tensorflow website has three very good tutorials to deal with word embedding, language modeling and sequence-to-sequence models. I don't have enough reputation to link them directly but you can easily find them here. They provide you with some tensorflow code to deal with human language
Moreover, if you want to build a model from scratch and you need only the dataset, try ntlk corpora. They are easy to download directly from the code.
Facebook's ParlAI project lists a good amount of datasets for Natural Language Processing tasks
IMDB's reviews dataset is also a classic example, also Amazon's reviews for sentiment analysis. If you take a look at kernels posted on Kaggle you'll get a lot of insights about the dataset and the task.
I'm not sure whether this task can be solved with machine learning and want to get some suggestions.
I want to search and list all the names of person from a random book (suppose they are all written in lower case). I can manually label a few names in the beginning for training purpose. I guess I can use some supervised learning algorithm, but I don't know what kind of features can be obtained because only available information I can think of in this scenario is the text of the book.
Can you give me a high level suggestion on steps to solve this question with machine learning?
Named Entity Recognition is pretty well-researched problem.
There are existing libraries solving it, for example this is a nice tutorial for Spacy.
Dear all I am working on a project in which I have to categories research papers into their appropriate fields using titles of papers. For example if a phrase "computer network" occurs somewhere in then title then this paper should be tagged as related to the concept "computer network". I have 3 million titles of research papers. So I want to know how I should start. I have tried to use tf-idf but could not get actual results. Does someone know about a library to do this task easily? Kindly suggest one. I shall be thankful.
If you don't know categories in advance, than it's not classification, but instead clustering. Basically, you need to do following:
Select algorithm.
Select and extract features.
Apply algorithm to features.
Quite simple. You only need to choose combination of algorithm and features that fits your case best.
When talking about clustering, there are several popular choices. K-means is considered one of the best and has enormous number of implementations, even in libraries not specialized in ML. Another popular choice is Expectation-Maximization (EM) algorithm. Both of them, however, require initial guess about number of classes. If you can't predict number of classes even approximately, other algorithms - such as hierarchical clustering or DBSCAN - may work for you better (see discussion here).
As for features, words themselves normally work fine for clustering by topic. Just tokenize your text, normalize and vectorize words (see this if you don't know what it all means).
Some useful links:
Clustering text documents using k-means
NLTK clustering package
Statistical Machine Learning for Text Classification with scikit-learn and NLTK
Note: all links in this answer are about Python, since it has really powerful and convenient tools for this kind of tasks, but if you have another language of preference, you most probably will be able to find similar libraries for it too.
For Python, I would recommend NLTK (Natural Language Toolkit), as it has some great tools for converting your raw documents into features you can feed to a machine learning algorithm. For starting out, you can maybe try a simple word frequency model (bag of words) and later on move to more complex feature extraction methods (string kernels). You can start by using SVM's (Support Vector Machines) to classify the data using LibSVM (the best SVM package).
The fact, that you do not know the number of categories in advance, you could use a tool called OntoGen. The tool basically takes a set of texts, does some text mining, and tries to discover the clusters of documents. It is a semi-supervised tool, so you must guide the process a little, but it does wonders. The final product of the process is an ontology of topics.
I encourage you, to give it a try.
I am working on a text mining project which focus on the computer technology documents. So there're many jargons. Tasks like part-of-speech tagging require some training data to built a pos-tagger. And I think this training data should be from the same domain with words like ".NET, COM, JAVA" correctly tagged.
So where can I find such corpus? Or is there any work around? Or can we tune an existing tagger to handle domain specific task?
Gathering training data (and defining features) is going to be the hardest step of this problem. I'm sure there are datasets out there. But an alternative option for you would be to identify a few journals or news sites that focus on your area of interest and crawl them and pull down the text, perhaps validating each article you pull down by searching for keywords. I've done that before to develop a corpus focused on elections.
Unfortunately, it is domain-specific where you can find such a corpus.
Catch-22. There is no general source for specialized data.
Just like there is no universal software to solve domain-specific problems.