How can I merge Sentiment Analysis Results from different sources? - machine-learning

I have a text I want analyze and send it to several Sentiment Analysis APIs and store the result of them. This text can be a tweet for example.
In the training phase, a human defines the real sentiment of the text and the APIs with the same answer get a better ranking. The machine also analyzes the Main Topic of the Text.
In the Use phase:
The machine receives a text, analyzes the Main Topic of the text, says which APIs worked best for that topic and merges these best APIs results based on their rating.
I thought about something like a recommendation engine like prediction.io
Is this the best way to solve the problem?
What technologies can I use?

Related

Using NLP or machine learning to extract keywords off a sentence

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.

Find startup's industry from its description

I am using AngelList DB to categorize startups based on their industries since these startups are categorized based on community input which is misleading most of the time.
My business objective is to extract keywords that indicate to which industry this specific startup belongs to then map it to one of the industries specified in LinkedIn sheet https://developer.linkedin.com/docs/reference/industry-codes
I experimented with Azure Machine learning, where I pushed 300 startups descriptions and analyzed the keyword extraction was pretty bad and was not even close to what I am trying to achieve.
I would like to know how data scientists will approach this problem? where should I look? and where I should not? is keyword analysis tools (like Google Adwords keyword planner is a viable option)
Using Text Classification...
To be able to treat this as a classification problem, you need a training set, which is a set of AngelList entries that are labeled with correct LinkedIn categories. This can be done manually, or you can hire some Mechanical Turks to do the job for you.
Since you have ~150 categories, I'd imagine you need at least 20-30* AngelList entries for each of them. So your training set will be {input: angellist_description, result: linkedin_id}
After that, you need to dig through text classification techniques to try and optimize the accuracy/precision of your results. The book "Taming Text" has a full chapter on text classification. And a good tool to implement a text-based classifier would be Apache Solr or Apache Lucene.
* 20-30 is a quick personal estimate and not based on a scientific method. You can look up some methods online for a good estimation method.
Using Text Clustering.
Step #1
Use text clustering to extract main 'topics' from all the descriptions. (Carrot2 can be helpful here)
Input corpus of all descriptions
Process: Text Clustering using Carrot2
Output each document will be labeled with a topic
Step #2
Manually map the extracted topics into LinkedIn's categories.
Step #3
Use the output of the first two steps to traverse from company -> extracted topic -> linkedin category

Can I use storm in census database?

So far that I know about Storm, that it's used to analyze Twitter tweets to get trending topics, but can it be used to analyze data from government's census? And because the data is structured, is storm suitable for that?
Storm is generally used for processing unending streams of data, e.g. logs, the twitter stream, or in my case the output of a web crawler.
I believe census type data would be in the form of a fixed report, which could be treated as a stream, but would probably lend itself better to processing via something like Map Reduce, using Hadoop (possibly with cacading or scalding as layers of abstraction over the details).
The structured nature of the data wouldn't prevent use of any of these technologies, that's more related to the problem you are trying to solve.
Storm is designed for streaming data processing, where the data is coming continuously. Your application has all the data it needs to process available, so a Batch processing is more suited. If the data is structured, you can use R or other tools for analysis, or write scripts to convert the data so that it can go to R as input. If its a humongous dataset, & u want to process it faster, only then think of getting into Hadoop & writing your program as per the analysis you have to do. Suggesting an architecture is only possible if you provide more details regarding data size, & what sort of analysis you are looking forward to do on it. If its a smaller dataset, both hadoop & storm can be an overkill for the problem that has to be solved.
--gtaank

Where to find domain-specific corpus for a text mining task?

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.

Disease named entity recognition

I have a bunch of text documents that describe diseases. Those documents are in most cases quite short and often only contain a single sentence. An example is given here:
Primary pulmonary hypertension is a progressive disease in which widespread occlusion of the smallest pulmonary arteries leads to increased pulmonary vascular resistance, and subsequently right ventricular failure.
What I need is a tool that finds all disease terms (e.g. "pulmonary hypertension" in this case) in the sentences and maps them to a controlled vocabulary like MeSH.
Thanks in advance for your answers!
Here are two pipelines that are specifically designed for medical document parsing:
Apache cTAKES
NLM's MetaMap
Both use UMLS, the unified medical language system, and thus require that you have a (free) license. Both are Java and more or less easy to set up.
See http://www.ebi.ac.uk/webservices/whatizit/info.jsf
Whatizit is a text processing system that allows you to do textmining
tasks on text. The tasks come defined by the pipelines in the drop
down list of the above window and the text can be pasted in the text
area.
You could also ask biostars: http://www.biostars.org/show/questions/
there are many tools to do that. some popular ones:
NLTK (python)
LingPipe (java)
Stanford NER (java)
OpenCalais (web service)
Illinois NER (java)
most of them come with some predefined models, i.e. they've already been trained on some general datasets (news articles, etc.). however, your texts are pretty specific, so you might want to first constitute a corpus and re-train one of those tools, in order to adjust it to your data.
more simply, as a first test, you can try a dictionary-based approach: design a list of entity names, and perform some exact or approximate matching. for instance, this operation is decribed in LingPipe's tutorial.
Open Targets has a module for this as part of LINK. It's not meant to be used directly so it might require some hacking and tinkering, but it's the most complete medical NER (named entity recognition) tool I've found for python. For more info, read their blog post.
a bash script that has as example a lexicon generated from the disease ontology:
https://github.com/lasigeBioTM/MER

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