NLP - linguistic consistency analysis - nlp

I hope you can help me :).
I am working for a translation company.
As you know, every translation consists in splitting the original text into small segments and then re-joining them into the final product.
In other words, the segments are considered as "translation units".
Often, especially for large documents, the translators make some linguistic consistency errors, I try to explain it with an example.
In Spanish, you can use "tu" or "usted", depending on the context, and this determines the formality-informality tone of the sentence.
So, if you consider these two sentences of a document:
Lara, te has lavado las manos? (TU)
Lara usted se lavò las manos? (USTED)
They are BOTH correct, but if you consider the whole document, there is a linguistic inconsistency.
I am studying NLP basic in my spare time, and I am figuring out how to create a tool to perform a linguistic consistency analysis on a set of sentences.
I am looking in particular at Standford CoreNLP (I prefer Java to Python).
I guess that I need some linguistic tools to perform verb analysis first of all. And naturally, the tool would be able to work with different languages (EN, IT, ES, FR, PT).
Anyone can help me to figure out how to start this?
Any help would be appreciated,
thanks in advance!

Im not sure about Stanford CoreNLP, but if you're considering this an option, you could make your own tagger and use modifiers at pos tagging. Then, use this as a translation feature.
In other words, instead of just tagging a word to be a verb, you could tag it "a verb in the infinitive second person".
There are already good pre-tagged corpora out there for spanish that can help you do exactly that. For example, if you look at Universal Dependencies Ankora Corpus, you can find that there are annotations referring to the Person of a verb.
With a little tweaking, you could make a compose PoS that takes in "Verb-1st-Person" or something like that and train a Tagger.
I've made an article about how to do it in Python, but I bet that you can do it in Java using Weka. You can read the article here.
After this, I guess that the next step is that you ensure to match the person of one "translation unit" to the other, or make something in a pipeline fashion.

Related

Determining Grammatical Validity of Text Input

I am looking for some way to determine if textual input takes the form of a valid sentence; I would like to provide a warning to the user if not. Examples of input I would like to warn the user about:
"dog hat can ah!"
"slkj ds dsak"
It seems like this is a difficult problem, since grammars are usually derived from textbanks, and the words in the provided sentence input might not appear in the grammar. It also seems like parsers maybe make assumptions that the textual input is comprised of valid English words to begin with. (just my brief takeaway from playing around with Stanford NLP's GUI tool). My questions are as follows:
Is there some tool available to scan through text input and determine if it is made up of valid English words, or at least offer a probability on that? If not, I can write this, just wondering if it already exists. I figure this would be step 1 before determining grammatical correctness.
My understanding is that determining whether a sentence is grammatically correct is done simply by attempting to parse the sentence and see if it is possible. Is that accurate? Are there probabilistic parsers that offer a degree of confidence when ambiguity is encountered? (e.g., a proper noun not recognized)
I hesitate to ask this last question, since I saw it was asked on SO over a decade ago, but any updates as to whether there is a basic, readily available grammar for NLTK? I know English isn't simple, but I am truly just looking to parse relatively simple, single sentence input.
Thanks!
A starting point are classification models trained on the Corpus of Linguistic Acceptability (CoLA) task. There are several recent blog articles on how to fine tune the BERT models from HuggingFace (python) for this task. Here is one such blog article. You can also find already fine-tuned models for CoLA for various BERT flavors in the HuggingFace model zoo.

How to extract meaning of colloquial phrases and expressions in English

I am looking into extracting the meaning of expressions used in everyday speaking. For an instance, it is apparent to a human that the sentence The meal we had at restaurant A tasted like food at my granny's. means that the food was tasty.
How can I extract this meaning using a tool or a technique?
The method I've found so far is to first extract phrases using Stanford CoreNLP POS tagging, and use a Word Sense Induction tool to derive the meaning of the phrase. However, as WSI tools are used to get the meaning of words when they have multiple meanings, I am not sure if it would be the best tool to use.
What would be the best method to extract the meanings? Or is there any tool that can both identify phrases and extract their meanings?
Any help is much appreciated. Thanks in advance.
The problem you pose is a difficult one. You should use tools from Sentiment Analysis to get a gist of the sentence emotional message. There are more sophisticated approaches which attempt at extracting what quality is assigned to what object in the sentence (this you can get from POS-tagged sentences + some hand-crafted Information Extraction rules).
However, you may want to also explore paraphrasing the more formal language to the common one and look for those phrases. For that you would need to a good (exhaustive) dictionary of common expressions to start with (there are sometimes slang dictionaries available - but I am not aware of any for English right now). You could then map the colloquial ones to some more formal ones which are likely to be caught by some embedding space (frequently used in Sentiment Analysis).

Techniques other than RegEx to discover 'intent' in sentences

I'm embarking on a project for a non-profit organization to help process and classify 1000's of reports annually from their field workers / contractors the world over. I'm relatively new to NLP and as such wanted to seek the group's guidance on the approach to solve our problem.
I'll highlight the current process, and our challenges and would love your help on the best way to solve our problem.
Current process: Field officers submit reports from locally run projects in the form of best practices. These reports are then processed by a full-time team of curators who (i) ensure they adhere to a best-practice template and (ii) edit the documents to improve language/style/grammar.
Challenge: As the number of field workers increased the volume of reports being generated has grown and our editors are now becoming the bottle-neck.
Solution: We would like to automate the 1st step of our process i.e., checking the document for compliance to the organizational best practice template
Basically, we need to ensure every report has 3 components namely:
1. States its purpose: What topic / problem does this best practice address?
2. Identifies Audience: Who is this for?
3. Highlights Relevance: What can the reader do after reading it?
Here's an example of a good report submission.
"This document introduces techniques for successfully applying best practices across developing countries. This study is intended to help low-income farmers identify a set of best practices for pricing agricultural products in places where there is no price transparency. By implementing these processes, farmers will be able to get better prices for their produce and raise their household incomes."
As of now, our approach has been to use RegEx and check for keywords. i.e., to check for compliance we use the following logic:
1 To check "states purpose" = we do a regex to match 'purpose', 'intent'
2 To check "identifies audience" = we do a regex to match with 'identifies', 'is for'
3 To check "highlights relevance" = we do a regex to match with 'able to', 'allows', 'enables'
The current approach of RegEx seems very primitive and limited so I wanted to ask the community if there is a better way to solving this problem using something like NLTK, CoreNLP.
Thanks in advance.
Interesting problem, i believe its a thorough research problem! In natural language processing, there are few techniques that learn and extract template from text and then can use them as gold annotation to identify whether a document follows the template structure. Researchers used this kind of system for automatic question answering (extract templates from question and then answer them). But in your case its more difficult as you need to learn the structure from a report. In the light of Natural Language Processing, this is more hard to address your problem (no simple NLP task matches with your problem definition) and you may not need any fancy model (complex) to resolve your problem.
You can start by simple document matching and computing a similarity score. If you have large collection of positive examples (well formatted and specified reports), you can construct a dictionary based on tf-idf weights. Then you can check the presence of the dictionary tokens. You can also think of this problem as a binary classification problem. There are good machine learning classifiers such as svm, logistic regression which works good for text data. You can use python and scikit-learn to build programs quickly and they are pretty easy to use. For text pre-processing, you can use NLTK.
Since the reports will be generated by field workers and there are few questions that will be answered by the reports (you mentioned about 3 specific components), i guess simple keyword matching techniques will be a good start for your research. You can gradually move to different directions based on your observations.
This seems like a perfect scenario to apply some machine learning to your process.
First of all, the data annotation problem is covered. This is usually the most annoying problem. Thankfully, you can rely on the curators. The curators can mark the specific sentences that specify: audience, relevance, purpose.
Train some models to identify these types of clauses. If all the classifiers fire for a certain document, it means that the document is properly formatted.
If errors are encountered, make sure to retrain the models with the specific examples.
If you don't provide yourself hints about the format of the document this is an open problem.
What you can do thought, is ask people writing report to conform to some format for the document like having 3 parts each of which have a pre-defined title like so
1. Purpose
Explains the purpose of the document in several paragraph.
2. Topic / Problem
This address the foobar problem also known as lorem ipsum feeling text.
3. Take away
What can the reader do after reading it?
You parse this document from .doc format for instance and extract the three parts. Then you can go through spell checking, grammar and text complexity algorithm. And finally you can extract for instance Named Entities (cf. Named Entity Recognition) and low TF-IDF words.
I've been trying to do something very similar with clinical trials, where most of the data is again written in natural language.
If you do not care about past data, and have control over what the field officers write, maybe you can have them provide these 3 extra fields in their reports, and you would be done.
Otherwise; CoreNLP and OpenNLP, the libraries that I'm most familiar with, have some tools that can help you with part of the task. For example; if your Regex pattern matches a word that starts with the prefix "inten", the actual word could be "intention", "intended", "intent", "intentionally" etc., and you wouldn't necessarily know if the word is a verb, a noun, an adjective or an adverb. POS taggers and the parsers in these libraries would be able to tell you the type (POS) of the word and maybe you only care about the verbs that start with "inten", or more strictly, the verbs spoken by the 3rd person singular.
CoreNLP has another tool called OpenIE, which attempts to extract relations in a sentence. For example, given the following sentence
Born in a small town, she took the midnight train going anywhere
CoreNLP can extract the triple
she, took, midnight train
Combined with the POS tagger for example; you would also know that "she" is a personal pronoun and "took" is a past tense verb.
These libraries can accomplish many other tasks such as tokenization, sentence splitting, and named entity recognition and it would be up to you to combine all of these tools with your domain knowledge and creativity to come up with a solution that works for your case.

Extracting information from unstructured text

I have a collection of "articles", each 1 to 10 sentences long, written in a noisy, informal english (i.e. social media style).
I need to extract some information from each article, where available, like date and time. I also need to understand what the article is talking about and who is the main "actor".
Example, given the sentence: "Everybody's presence is required tomorrow morning starting from 10.30 to discuss the company's financial forecast.", I need to extract:
the date/time => "10.30 tomorrow morning".
the topic => "company's financial forecast".
the actor => "Everybody".
As far as I know, the date and time could be extracted without using NLP techniques but I haven't found anything as good as Natty (http://natty.joestelmach.com/) in Python.
My understanding on how to proceed after reading some chapters of the NLTK book and watching some videos of the NLP courses on Coursera is the following:
Use part of the data to create an annotated corpus. I can't use off-the-shelf corpus because of the informal nature of the text (e.g. spelling errors, uninformative capitalization, word abbreviations, etc...).
Manually (sigh...) annotate each article with tags from the Penn TreeBank tagset. Is there any way to automate this step and just check/fix the results ?
Train a POS tagger on the annotated article. I've found the NLTK-trainer project that seems promising (http://nltk-trainer.readthedocs.org/en/latest/train_tagger.html).
Chunking/Chinking, which means I'll have to manually annotate the corpus again (...) using the IOB notation. Unfortunately according to this bug report n-gram chunkers are broken: https://github.com/nltk/nltk/issues/367. This seems like a major issue, and makes me wonder whether I should keep using NLTK given that it's more than a year old.
At this point, if I have done everything correctly, I assume I'll find actor, topic and datetime in the chunks. Correct ?
Could I (temporarily) skip 1,2 and 3 and produce a working, but possibly with a high error rate, implementation ? Which corpus should I use ?
I was also thinking of a pre-process step to correct common spelling mistakes or shortcuts like "yess", "c u" and other abominations. Anything already existing I can take advantage of ?
THE question, in a nutshell, is: is my approach at solving this problem correct ? If not, what am I doing wrong ?
Could I (temporarily) skip 1,2 and 3 and produce a working, but
possibly with a high error rate, implementation ? Which corpus should
I use ?
I was also thinking of a pre-process step to correct common spelling
mistakes or shortcuts like "yess", "c u" and other abominations.
Anything already existing I can take advantage of ?
I would suggest you first have a go at processing standard language text. The pre-processing you refer to is an NLP task in its own right, known as normalization. Here is a resource for Twitter normalization: http://www.ark.cs.cmu.edu/TweetNLP/ , additionally, you can use spell checking, sentence boundary detection, ...
THE question, in a nutshell, is: is my approach at solving this
problem correct ? If not, what am I doing wrong ?
If you make abstraction of normalization, I think your approach is valid. With regard to automating the annotation process: you can bootstrap the process by using off-the-shelf components first, after which you correct, retrain, and so on, ... during different iterations. To get acceptable results, you will need to do your steps 2, 3, and 4 a couple of times.
If you are interested in understanding the problem and being able to optimize existing solutions, I would suggest you focus on tools that allow you to develop your own models. If you prioritize getting results over being able to develop your own models, I would recommend looking into existing open source text engineering frameworks such as Gate (https://gate.ac.uk/) UIMA (http://uima.apache.org/) and DKPro (which extends UIMA) (https://code.google.com/p/dkpro-core-asl/). All three frameworks wrap existing components, so you have a wide range of possible solutions.
I'd suggesting giving a try to NER and Temporal Normalizer.
Here is what I see for your example sentence:
You can try the demo here:
http://deagol.cs.illinois.edu:8080/

Natural Language Generation - how to test if it sounds natural

I just have a set of sentences, which I have generated based on painting analysis. However I need to test how natural they sound. Is there any api or application which does this?
I am using the Standford Parser to give me a breakdown, but this doesn't exactly do the job I want!
Also can one test how similar sentences are? As I randomly generating parts of sentences and want to check the variety of the sentences produced.
A lot of NLP stuff works using things called 'Language Models'.
A language model is something that can take in some text and return a probability. This probability should typically be indicative of how "likely" the given text is.
You typically build a language model by taking a large chunk of text (which we call the "training corpus") and computing some statistics out of it (which represent your "model"), and then using those statistics to take in new, previously unseen sentences and returning probabilities for them.
You should probably google for "language models", "unigram models", "n-gram models" and click on some of the results to find some article or presentation which helps you understand the previous sentence. (Its hard for me to recommend an appropriate tutorial for you because I don't know what your existing background is)
Anyway, one way to think about language models is that they are systems that take in new text and tell you how similar the new text is to the training corpus the language model was made out of. So if you build 2 language models, one out of all the plays written by Shakespeare and another out of a large number of legal documents, then the second one should be giving you a much higher probability to sentences for some new legal document that just got released (as compared to the first model) while the first model should give you a much higher probability for some other old english play (written by some other author) because that play is probably more similar to Shakespeare (in terms of the kind of words used, sentence lengths, grammar, etc) than it is to modern legal language.
All the things you see the stanford parser give you back for a sentence you give it are generated using language models. One way to think about how those features are built is to pretend that the computer tried every possible combination of tags and every possible parse tree for the sentence you gave it, and used some clever language model to identify which is most probable sequence of tags and most probable parse tree out there, and returned those back to you.
Getting back to your problem, you need to build a language model out of what you consider natural sounding text and then use that language model to evaluate the sentences you want to measure the naturalness of. To do this, you will have to identify a good training corpus and decide on what type of language model you want to build.
If you can't think of anything better, a collection of wikipedia articles might serve to be a good training corpus representing what natural sounding english looks like.
As for model type, an "n-gram model" would probably be good enough for your task. More complicated models like "Hidden Markov Models" and "PCFG's" (the stuff that is powering the stanford page you linked to) would definitely make things even better, but n-grams are definitely the most simple thing you could start with.

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