Update May 2016: Kimono has been adquired by Palantir and its cloud service has been discontinued. We have made a new post covering how to create a hotel reviews sentiment analysis model with Scrapy and MonkeyLearn, check it out here

New tools have enabled businesses of all sizes to understand how their customers are reacting to them – do customers like the location, hate the menu, would they come back? This increased volume of data is incredibly valuable but larger than any mere mortal can assess, understand and turn into action. Several technologies have emerged to help businesses unlock the meaning behind this data.

This blog looks at how Kimono Labs, which structures data at scale, and MonkeyLearn, which provides machine learning capabilities, can be used together to translate data into insight.

Kimono + MonkeyLearn

Kimono is a smart web scraper for getting data from the web by turning websites into APIs. By using Kimono point-and-click tool, users can select the data they want to scrape from a website and Kimono does the rest, turning websites into APIs in seconds.

MonkeyLearn is a platform for getting relevant data from text using machine learning. MonkeyLearn goal is to enable developers with any level of experience to easily extract and classify information from text for their specific needs, and integrate the technology into their own platforms and applications in a easy, fast and cost-effective way.

There is a natural fit between Kimono and MonkeyLearn; with Kimono you can extract information from the web and with MonkeyLearn you can create and use machine learning models to enrich that information with sentiment analysis, topic detection, language detection, keyword detection, entity recognition and more.

Combine both services and the possibilities are endless.

How to create a hotel sentiment analysis detector with Kimono and MonkeyLearn

Our objective with this tutorial is to create a tool that performs sentiment analysis of hotel reviews.

We will use Kimono to extract hotel reviews from TripAdvisor and use those reviews as training samples to create a machine learning model with MonkeyLearn. This model will learn to detect if a hotel review is positive or negative and will be able to understand the sentiment of new and unseen hotel reviews.

1. Create a Kimono API

The first step is to scrape hotel reviews from TripAdvisor by creating a Kimono API:

Install the Kimono chrome extension
For more information on how to install Kimono extension visit this article.

Use Kimono on a webpage
To use kimono, navigate to the webpage you want to extract data from, and then click on the chrome extension. In this tutorial we will use New York Inn reviews to create our hotel sentiment analysis classifier.

Select the data you want to scrape with Kimono
If you need help with this step, follow this simple tutorial. In our case we will extract the review title, the review content and the stars:

review

In order to do that, we will have to add three properties “title”, “content”  and “stars”, and mark the corresponding fields on the webpage. Kimono will recognize similar fields for every review on the current page:

reviews_contents

After marking all the properties, we have to mark the pagination link, that is, the link that will get the crawler to the next page of reviews. You can do that by marking the next page link with Kimono’s pagination activation icon I_Pagination:

reviews_pagination

Before we create our Kimono API, we have to do some advanced configurations in the stars attribute to get the alt value, that is, we want to get strings like “1 of 5 stars” or “5 of 5 stars”. You can do that by clicking the Data Model View and configuring the advanced attributes for the stars property:

stars_attribute

You can go to the Raw Data View to verify that our crawler gets the correct property values:

raw_data_view

And we are done! Now just click the Done button. On the creation form, select manual crawl as your API setting and set the crawl limit to 50 pages max:

create_api

2. Getting the Data

So we have our Kimono spider created, we are ready to start crawling and gathering the data. You just have to go the Crawl Setup tab in your API Detail and hit the Start Crawl button:

manual_crawl

The crawl will start, it will take a few seconds to finish. To get the retrieved data, go to the Data Preview tab, select the CSV format and click the Download link:

data_download

3. Preparing the Data

So we downloaded our kimonoData.csv file, now it’s time to preprocess the data. We’ll do that with Python and Pandas library.

First we import the csv file into a data frame, remove duplicates, drop the reviews that are neutral (3 of 5 stars):

Then we create a new column that concatenates the title and the content:

Then we create a new column that will be what we want to predict: Good or Bad, so we transform reviews with more than 3 stars into Good, and reviews with less than 3 stars into Bad:

We’ll keep only the full_content and true_category columns:

If we take a look at the data frame we created it may look something like this:

data_table

To have a quick overview of the data, we have 429 Good reviews and 225 Bad reviews:

Finally, we have to save our dataset in MonkeyLearn’s format, so we remove the headers and the index column. The first column must be the text contents and the second must be the category. We will encode the text in UTF-8:

4. Creating a MonkeyLearn Classifier

Ok, time to move to MonkeyLearn, we want to create a text classifier that classifies reviews into two possible categories: Good or Bad, depending on that the review is talking in a positive or negative way respectively. That process is known as Sentiment Analysis, that is, extracting the mood from a text.

First you have to signup into Monkeylearn, after you log in you will get into the main dashboard. MonkeyLearn has precreated text mining modules, but also allows you to create customized ones. In our case, we will build a custom text classifier, so within Classification page, click the Create Module button:

MonkeyLearn_classification_create

A form will popup, to fill the initial settings, we first select English as our working language and name our new module as “Hotel Sentiment“:

MonkeyLearn_create_module

Also, we will set some advanced options, click the Show advanced options link and:

  • Set N-gram range to 1-3.
  • Disable Use stemming.
  • Enable Filter stopwords, and use Custom stopwords: “the, and”.

MonkeyLearn_advanced_options

After clicking the Create button, we will be in the module detail page.

5. Feeding MonkeyLearn with Kimono

Time to feed the monkey, go to the Actions menu and select Upload tree, then select the CSV file we created with Kimono’s data:

MonkeyLearn_upload

After the uploading finishes, MonkeyLearn will create the corresponding category tree at the left, where we will have three nodes: Root (the starting point) and our to sentiment categories: Good and Bad. If you click on each of the categories, you will see the corresponding text samples (the reviews we gathered with Kimono) on a list on the bottom right of the screen:

MonkeyLearn_category_samples

6. Train MonkeyLearn

Ok, now an easy step: training the machine learning algorithm. This only involves hitting the Train button at the top right of the screen. You will see a progress bar while the machine learning algorithms are training the model in MonkeyLearn’s cloud. It will take a few seconds or a few minutes depending on the complexity and size of your category tree and samples.

After finishing the training, the module state will change to TRAINED, and you’ll get some statistics that show how well the module is doing in predicting the correct category (in our case the sentiment):

MonkeyLearn_trained

The metrics are Accuracy, Precision and Recall, this measurements are common in machine learning for evaluating the performance of classification algorithms.

You can also see a keyword cloud on the right, that shows some of the terms that will be used to characterize the samples and predict the sentiment of the text. As you can see, they are terms that are semantically associated with positive and negative expressions about hotel features. Those terms are automatically obtained with statistical algorithms within MonkeyLearn.

If you want to look at the finished classifier, we created a public classifier with the hotel sentiment analysis.

7. Testing our Sentiment Analysis

And voilá, we have our sentiment analysis classifier with zero lines of code. We can test the model directly from the GUI within MonkeyLearn. Go to the API tab, there you write or paste a text, submit and you’ll get the prediction, for example:

MonkeyLearn_test

The results shows what a call to the classification endpoint from MonkeyLearn’s API would respond. What is important now is to take a look at the “result” entry that shows the predicted label, in this case “Good”, and the corresponding probability: 1. The label in our case will always be Good or Bad, and the probability is a real number between 0 and 1. 1 means that is 100% sure about the prediction.

You the classifier may still have some errors, that is, classify good reviews as bad, and vice versa, but the good thing is that you can keep improving, if you gather more training samples with tools like Kimono (in our example, by getting reviews from more hotels), you can upload more samples to the classifier, retrain and improve the results. Also, you can try different configurations on the advanced settings of your classifier, and retrain the algorithm. Usually different settings work for different classification problems (it’s not the same to do topic detection or sentiment analysis).

8. Integrating the module with MonkeyLearn’s API

You can do the same but programmatically, so you can easily integrate any MonkeyLearn module within your projects with any programming language. For example, if we are working with Python programming language, you can go to a bit down to the API libraries, select the corresponding programming language and copy and paste the code snippet:

MonkeyLearn_api

Conclusion

We combined Kimono and MonkeyLearn to create a machine learning model that learns to predict the sentiment of a hotel review. Kimono helped us to easily retrieve the training data from the web and MonkeyLearn helped us to build the actual sentiment analysis classifier.

But this is just the tip of the iceberg. There’s much more we can do.

If you are a Kimono user, you can use MonkeyLearn pre-trained modules to easily enrich your Kimono APIs and add sentiment analysis, topic detection, language detection, keyword extraction, entity recognition (and others) to the information you extract from the web with Kimono. If you have a specific need, you can create a custom module with MonkeyLearn to process the information you extract the way you need.

If you are a MonkeyLearn user, you can use Kimono to easily extract samples to train your custom modules and create powerful machine learning models in just a few minutes.

Have any cool ideas on how to combine Kimono and MonkeyLearn? Share them with us in the comments.