sentiment analysis using support vector machine
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SVM is a supervised machine learning algorithm that can be used for classification or regression. It works by finding the optimal hyperplane that separates classes by the largest margin. SVM identifies the hyperplane that results in the largest fractional distance between data points of separate classes. It can perform nonlinear classification using kernel tricks to transform data into higher dimensional space. SVM is effective for high dimensional data, uses a subset of training points, and works well when there is a clear margin of separation between classes, though it does not directly provide probability estimates. It has applications in text categorization, image classification, and other domains.
![References
• Mining Social Media Data for Understanding Students’ Learning Experiences
,Xin Chen, Student Member, IEEE, Mihaela Vorvoreanu, and Krishna Madhavan
• Machine Learning Algorithms for Opinion Mining and Sentiment Classification
Jayashri Khairnar,Mayura Kinikar[IJSRP].
• Managing Data in SVM Supervised Algorithm for Data Mining Technology
Sachin Bhaskart, Vijay Bahadur Singh2, A. K. Nayak.
• Wekipedia and Internet](https://image.slidesharecdn.com/sappt-170404015026/85/sentiment-analysis-using-support-vector-machine-22-320.jpg)
sentiment analysis using support vector machine
- 1. Sentiment Analysis using support vector machine Guide : Prof. S.B.Patil Presented by : Shital M. Andhale T120398502 Information Technology Dept, VIIT pune
- 2. Contents • What is sentiment analysis ? • Sentiment Analysis in Twitter or any other Social Media. • Sentiment Analysis Classification • Sentiment Analysis using machine learning • Types of Machine Learning • Support vector Machine Algorithm • How does it work ? • Pros and cons of SVM • Applications • Conclusion • references
- 3. What is Sentiment Analysis ? • Sentiment Analysis is the process of finding the opinion of user about some topic or the text in consideration. • It is also known as opinion mining. • In other words, it determines whether a piece of writing is positive, negative or neutral.
- 4. Sentiment Analysis in Social media or Twitter • Micro blogging websites are social media site (Twitter, Facebook) to which user makes short and frequent posts. • Twitter is one of the famous micro blogging services where user can read and post messages which are 148 characters in length. Twitter messages are also called as Tweets. • we will use these tweets as raw data. We will use a techniques that automatically extracts tweets into positive, negative or neutral sentiments. By using the sentiment analysis the customer can know the feedback about the product before making a purchase. Sentiment analysis is a type of natural language processing for tracking the mood of the public about a particular product or topic.
- 5. Classification of Sentiment Analysis Sentiment analyis Machine learning Approch Superwised learning Linear classifier Support Vector Machine Neural network Decision tree Rule based classifires Probablistic classifiers Unsuperwised learning
- 6. SA using machine learning Approch 6 • Machine learning is a type of artificial intelligence (AI) that provides computers with the ability to learn without being explicitly programmed. • The Machine that Teaches Themselves.
- 7. Types of machine learning • Supervised Learning Inferring a function from labelled training data. A supervised learning algorithm analyses the training data (a list of input and their correct output) and produces an appropriate function, which can be used for mapping new examples. • Unsupervised Learning Inferring a function to describe hidden structure from unlabelled data. No labels are given to the learning algorithm, leaving it on its own to find structure in its input.
- 8. Support Vector Machine Algorithm What is Support Vector Machine? • SVM is a non-probabilistic binary linear classifier. It has the ability to linearly separate the classes by a large margin. Add to it the Kernel, and SVM becomes one of the most powerful classifier capable of handling infinite dimensional feature vectors. • “Support Vector Machine” (SVM) is a supervised machine learning algorithm which can be used for both classification or regression challenges. However, it is mostly used in classification problems. • In this algorithm, we plot each data item as a point in n-dimensional space (where n is number of features you have) with the value of each feature being the value of a particular coordinate. Then, we perform classification by finding the hyper-plane that differentiate the two classes very well .
- 9. How does SVM work ?
- 10. Identify the right hyper-plane (Scenario-1): • Here, we have three hyper-planes (A, B and C). Now,identify the right hyper-plane to classify star and circle • You need to remember a thumb rule to identify the right hyper- plane: “Select the hyper-plane which segregates the two classes better”. In this scenario, hyper- plane “B” has excellently performed this job.
- 11. Identify the right hyper-plane (Scenario-2): Here, we have three hyper-planes (A, B and C) and all are segregating the classes well. Now, How can we identify the right hyper-plane? Here, maximizing the distances between nearest data point (either class) and hyper- plane will help us to decide the right hyper- plane. This distance is called as Margin Above, you can see that the margin for hyper- plane C is high as compared to both A and B. Hence, we name the right hyper-plane as C. Another lightning reason for selecting the hyper- plane with higher margin is robustness. If we select a hyper-plane having low margin then there is high chance of miss-classification.
- 12. Identify the right hyper-plane (Scenario-3) • SVM selects the hyper-plane which classifies the classes accurately prior to maximizing margin. Here, hyper-plane B has a classification error and A has classified all correctly. • Therefore, the right hyper-plane is A.
- 13. Can we classify two classes (Scenario-4)? Below, I am unable to segregate the two classes using a straight line, as one of star lies in the territory of other(circle) class as an outlier
- 14. Can we classify two classes (Scenario-4) As I have already mentioned, one star at other end is like an outlier for star class. SVM has a feature to ignore outliers and find the hyper-plane that has maximum margin. Hence, we can say, SVM is robust to outliers.
- 15. Find the hyper-plane to segregate to classes (Scenario- 5): • In the scenario below, we can’t have linear hyper-plane between the two classes, so how does SVM classify these two classes? Till now, we have only looked at the linear hyper-plane. • SVM can solve this problem. Easily! It solves this problem by introducing additional feature. Here, we will add a new feature z=x^2+y^2. Now, let’s plot the data points on axis x and z:
- 16. Find the hyper-plane to segregate to classes (Scenario- 5): In above plot, points to consider are: • All values for z would be positive always because z is the squared sum of both x and y • In the original plot, red circles appear close to the origin of x and y axes, leading to lower value of z and star relatively away from the origin result to higher value of z.
- 17. Find the hyper-plane to segregate to classes (Scenario-5): When we look at the hyper-plane in original input space it looks like a circle:
- 18. Pros and cons of SVM • Pros: • It works really well with clear margin of separation • It is effective in high dimensional spaces. • It is effective in cases where number of dimensions is greater than the number of samples. • It uses a subset of training points in the decision function (called support vectors), so it is also memory efficient. • Cons: • It doesn’t perform well, when we have large data set because the required training time is higher • It also doesn’t perform very well, when the data set has more noise i.e. target classes are overlapping • SVM doesn’t directly provide probability estimates, these are calculated using an expensive five-fold cross-validation.
- 19. Applications of SVM • SVMs can be used to solve various real world problems: • SVMs are helpful in text and hypertext categorization as their application can significantly reduce the need for labeled training instances in both the standard inductive and transductive settings • Classification of images can also be performed using SVMs. • Experimental results show that SVMs achieve significantly higher search accuracy than traditional query refinement schemes after just three to four rounds of relevance feedback. • This is also true of image segmentation systems, including those using a modified version SVM that uses the privileged approach as suggested by Vapnik. Hand-written characters can be recognized using SVM.
- 20. Naïve Bays SVM Maximum Entropy Easy to Implement Harder to Implement Harder to Implement Less Efficient, Efficient due to working with large sets of Words Efficiency is maximum Efficiency is moderate Limited Use Versatile Used in Comp Vision, Text Cat, IP Hardly used Comparison of ML algorithms
- 21. Conclusion The machine learning can prove efficient over traditional techniques for SA The Support Vector Machine algorithm can be useful in sentiment analysis of text categorization.
- 22. References • Mining Social Media Data for Understanding Students’ Learning Experiences ,Xin Chen, Student Member, IEEE, Mihaela Vorvoreanu, and Krishna Madhavan • Machine Learning Algorithms for Opinion Mining and Sentiment Classification Jayashri Khairnar,Mayura Kinikar[IJSRP]. • Managing Data in SVM Supervised Algorithm for Data Mining Technology Sachin Bhaskart, Vijay Bahadur Singh2, A. K. Nayak. • Wekipedia and Internet
- 23. Thank you ..