course what is one of the faults of the naïve bayes algorithm mentioned by the book?

by Camryn Bednar 6 min read

One of the disadvantages of Naïve-Bayes is that if you have no occurrences of a class label and a certain attribute value together then the frequency-based probability estimate will be zero. And this will get a zero when all the probabilities are multiplied.

Is naive Bayes a bad algorithm?

However, that’s not to say that it’s a poor algorithm despite the strong assumptions that it holds — in fact, Naive Bayes is widely used in the data science world and has a lot of real-life applications.

What is Gaussian naive Bayes in machine learning?

This extension of naive Bayes is called Gaussian Naive Bayes. Other functions can be used to estimate the distribution of the data, but the Gaussian (or Normal distribution) is the easiest to work with because you only need to estimate the mean and the standard deviation from your training data.

What is an example of naive algorithm?

Here’s an example: you’d consider fruit to be orange if it is round, orange, and is of around 3.5 inches in diameter. Now, even if these features require each other to exist, they all contribute independently to your assumption that this particular fruit is orange. That’s why this algorithm has ‘Naive’ in its name.

What is naive Bayes theorem?

It is based on the Bayes Theorem. It is called naive Bayes because it assumes that the value of a feature is independent of the other feature i.e. changing the value of a feature would not affect the value of the other feature. It is also called as idiot Bayes due to the same reason.

Why did Naive Bayes fail?

Given Naive-Bayes' conditional independence assumption, when all the probabilities are multiplied you will get zero and this will affect the posterior probability estimate. This problem happens when we are drawing samples from a population and the drawn vectors are not fully representative of the population.

Which of the following is correct about the Naive Bayes?

Q.Which of the following is true about Naive Bayes ?B.b. assumes that all the features in a dataset are independentC.c. both a and bD.d. none of the above optionAnswer» c. c. both a and b1 more row

What is the main assumption in the Naive Bayes classifier?

It is a classification technique based on Bayes' Theorem with an assumption of independence among predictors. In simple terms, a Naive Bayes classifier assumes that the presence of a particular feature in a class is unrelated to the presence of any other feature.

What is Naive Bayes discussed about?

Naive Bayes is a probabilistic algorithm that's typically used for classification problems. Naive Bayes is simple, intuitive, and yet performs surprisingly well in many cases. For example, spam filters Email app uses are built on Naive Bayes.

Which statement about Naive Bayes is incorrect?

Q.Which of the following statements about Naive Bayes is incorrect?C.attributes are statistically independent of one another given the class value.D.attributes can be nominal or numericAnswer» b. attributes are statistically dependent of one another given the class value.2 more rows

What is the naive Bayes algorithm used for MCQ?

Naïve Bayes algorithm is a supervised learning algorithm, which is based on Bayes theorem and used for solving classification problems. It is mainly used in text classification that includes a high-dimensional training dataset.

What are the drawbacks of the naive Bayesian model?

Disadvantages of Naive Bayes If your test data set has a categorical variable of a category that wasn't present in the training data set, the Naive Bayes model will assign it zero probability and won't be able to make any predictions in this regard.

Which assumption makes the naive Bayesian classifier different from the general Bayesian model?

Naive Bayes assumes conditional independence, P(X|Y,Z)=P(X|Z), Whereas more general Bayes Nets (sometimes called Bayesian Belief Networks) will allow the user to specify which attributes are, in fact, conditionally independent.

Which is better, a naive Bayes classifier or a naive Baye

Naive Bayes classifier performs better than other models with less training data if the assumption of independence of features holds. If you have categorical input variables, the Naive Bayes algorithm performs exceptionally well in comparison to numerical variables.

What is a naive Bayes classifier?

What is the Naive Bayes Classifier? The Naive Bayes classifier separates data into different classes according to the Bayes’ Theorem, along with the assumption that all the predictors are independent of one another. It assumes that a particular feature in a class is not related to the presence of other features.

What are the advantages of naive Bayes?

Advantages of Naive Bayes 1 This algorithm works very fast and can easily predict the class of a test dataset. 2 You can use it to solve multi-class prediction problems as it’s quite useful with them. 3 Naive Bayes classifier performs better than other models with less training data if the assumption of independence of features holds. 4 If you have categorical input variables, the Naive Bayes algorithm performs exceptionally well in comparison to numerical variables.

Where do you go when you need a fast problem solving algorithm?

When you need a fast problem-solving algorithm, where do you go? You go to the Naive Bayes classifier. It’s a quick and simple algorithm that can solve various classification problems. In this article, we’ll understand what this algorithm is, how it works, and what its qualities are. Let’s get started.

What is a fruit that is green, round, and has a 10-inch diameter?

For example, you can consider a fruit to be a watermelon if it is green, round and has a 10-inch diameter. These features could depend on each other for their existence, but each one of them independently contributes to the probability that the fruit under consideration is a watermelon.

What is a naive Bayes algorithm?

What is Naive Bayes Algorithm? The naive Bayes Algorithm is one of the popular classification machine learning algorithms that helps to classify the data based upon the conditional probability values computation.

What are the different types of naive Bayes?

There are three types of Naive Bayes models, i.e. Gaussian, Multinomial and Bernoulli. Let us discuss each of them briefly. 1. Gaussian: Gaussian Naive Bayes Algorithm assumes that the continuous values corresponding to each feature are distributed according to Gaussian distribution, also called as Normal distribution.

Naive Bayes Explained: so what is Naive Bayes then?

Naive Bayes is a simplification of Bayes’ theorem which is used as a classification algorithm for binary of multi-class problems.

Naive Bayes Explained: Conclusion

We have seen how we can use some simplification s of Bayes Theorem for classification problems. It is a widely used approach to serve as a baseline for more complex classification models, and it is also widely used in Natural Language Processing.

Additional Resources

In case you are hungry for more information, you can use the following resources:

Why is Naive Bayes used in text classification?

Most of the time, Naive Bayes finds uses in-text classification due to its assumption of independence and high performance in solving multi-class problems. It enjoys a high rate of success than other algorithms due to its speed and efficiency.

What is naive Bayes?

Naive Bayes is a machine learning algorithm we use to solve classification problems. It is based on the Bayes Theorem. It is one of the simplest yet powerful ML algorithms in use and finds applications in many industries.

What is a Naive Bayes classifier?

With the help of Collaborative Filtering, Naive Bayes Classifier builds a powerful recommender system to predict if a user would like a particular product (or resource) or not. Amazon, Netflix, and Flipkart are prominent companies that use recommender systems to suggest products to their customers.

Why is naive Bayes useful?

Advantages. This algorithm works quickly and can save a lot of time. Naive Bayes is suitable for solving multi-class prediction problems. If its assumption of the independence of features holds true, it can perform better than other models and requires much less training data.

What is the Bayes theorem?

Naive Bayes uses the Bayes’ Theorem and assumes that all predictors are independent. In other words, this classifier assumes that the presence of one particular feature in a class doesn’t affect the presence of another one.

What is a naive Bayes algorithm?

1. Introduction. Naive Bayes is a probabilistic machine learning algorithm that can be used in a wide variety of classification tasks. Typical applications include filtering spam, classifying documents, sentiment prediction etc.

What is the Bayes rule?

The Bayes Rule provides the formula for the probability of Y given X. But, in real-world problems, you typically have multiple X variables. When the features are independent, we can extend the Bayes Rule to what is called Naive Bayes.

Why is the name "naive" used?

The name naive is used because it assumes the features that go into the model is independent of each other. That is changing the value of one feature, does not directly influence or change the value of any of the other features used in the algorithm. Alright.

What is a naive Bayes algorithm?

Last Updated on August 15, 2020. Naive Bayes is a simple but surprisingly powerful algorithm for predictive modeling. In this post you will discover the Naive Bayes algorithm for classification. After reading this post, you will know:

What is a naive Bayes?

Naive Bayes is a classification algorithm for binary (two-class) and multi-class classification problems. The technique is easiest to understand when described using binary or categorical input values.

Why is learning a Bayes model fast?

Training is fast because only the probability of each class and the probability of each class given different input (x) values need to be calculated. No coefficients need to be fitted by optimization procedures.

Why is Naive Bayes so simple to understand?

Part of why it’s so simple to understand and implement is because of the assumptions that it inherently makes. However, that’s not to say that it’s a poor algorithm despite the strong assumptions that it holds — in fact, Naive Bayes is widely used in the data science world and has a lot of real-life applications.

When to use naive Bayes?

This means that Naive Bayes is used when the output variable is discrete. The underlying mechanics of the algorithm are driven by the Bayes Theorem, which you’ll see in the next section.

What is a multinomial bayes?

Multinomial Naive Bayes assumes that each P (xn|y) follows a multinomial distribution. It is mainly used in document classification problems and looks at the frequency of words, similar to the example above.

What is Bayes theorem?

Bayes Theorem: according to Wikipedia, Bayes’ Theorem describes the probability of an event (posterior) based on the prior knowledge of conditions that might be related to the event.

Is Naive Bayes a real time model?

In fact, a lot of popular real-time models or online models are based on Bayesian statistics. Multiclass prediction: As previously stated, Naive Bayes works well when there are more than two classes for ...

Does Naive Bayes work with discrete variables?

Since Naive Bayes works best with discrete variables, it tends to work well in these applications.

What is a naive Bayes classifier?

Naive Bayes classifiers are a collection of classification algorithms based on Bayes’ Theorem. It is not a single algorithm but a family of algorithms where all of them share a common principle, i.e. every pair of features being classified is independent of each other.

Why is Bayes' assumption naive?

In-fact, the independence assumption is often not meet and this is why it is called “ Naive ” i.e. because it assumes something that might not be true. 2.2. The Bayes’ Theorem.

Introduction to The Naïve Bayes Algorithm

Image
The simplest solutions are usually the most powerful ones, and Naïve Bayesis a good example of that. Despite the advances in Machine Learning in the last years, it has proven to not only be simple but also fast, accurate, and reliable. It has been successfully used for many purposes, but it works particularly well with natural la…
See more on kdnuggets.com

Bayes Theorem

  • Bayes’ Theorem is a simple mathematical formula used for calculating conditional probabilities. Conditional probabilityis a measure of the probability of an event occurring given that another event has (by assumption, presumption, assertion, or evidence) occurred. The formula is: — Which tells us: how often A happens given that B happens, written P(A|B) also called posterior probabili…
See more on kdnuggets.com

Naïve Bayes Example

  • The dataset is represented as below. Concerning our dataset, the concept of assumptions made by the algorithm can be understood as: 1. We assume that no pair of features are dependent. For example, the color being ‘Red’ has nothing to do with the Type or the Origin of the car. Hence, the features are assumed to be Independent. 2. Secondly, each feature is given the same influence(…
See more on kdnuggets.com

Types of Naïve Bayes Classifiers

  • 1. Multinomial Naïve Bayes Classifier
    Feature vectors represent the frequencies with which certain events have been generated by a multinomial distribution. This is the event model typically used for document classification.
  • 2. Bernoulli Naïve Bayes Classifier:
    In the multivariate Bernoulli event model, features are independent booleans (binary variables) describing inputs. Like the multinomial model, this model is popular for document classification tasks, where binary term occurrence (i.e. a word occurs in a document or not) features are used …
See more on kdnuggets.com

Case Study: Naïve Bayes Classifier from Scratch Using Python

  • An existing problem for any major website today is how to handle virulent and divisive content. Quora wants to tackle this problem to keep its platform a place where users can feel safe sharing their knowledge with the world. Quorais a platform that empowers people to learn from each other. On Quora, people can ask questions and connect with others who contribute unique insig…
See more on kdnuggets.com

Conclusion

  • Naïve Bayes algorithms are often used in sentiment analysis, spam filtering, recommendation systems, etc. They are quick and easy to implement but their biggest disadvantage is that the requirement of predictors to be independent. Thanks for Reading! Nagesh Singh Chauhanis a Big data developer at CirrusLabs. He has over 4 years of working experience in various sectors like …
See more on kdnuggets.com

What Is The Naive Bayes classifier?

  • The Naive Bayes classifier separates data into different classes according to the Bayes’ Theorem, along with the assumption that all the predictors are independent of one another. It assumes that a particular feature in a class is not related to the presence of other features. For example, you can consider a fruit to be a watermelon if it is green, round and has a 10-inch diameter. These fe…
See more on upgrad.com

Advantages of Naive Bayes

  1. This algorithm works very fast and can easily predict the class of a test dataset.
  2. You can use it to solve multi-class prediction problems as it’s quite useful with them.
  3. Naive Bayes classifier performs better than other models with less training data if the assumption of independence of features holds.
  4. If you have categorical input variables, the Naive Bayes algorithm performs exceptionally wel…
  1. This algorithm works very fast and can easily predict the class of a test dataset.
  2. You can use it to solve multi-class prediction problems as it’s quite useful with them.
  3. Naive Bayes classifier performs better than other models with less training data if the assumption of independence of features holds.
  4. If you have categorical input variables, the Naive Bayes algorithm performs exceptionally well in comparison to numerical variables.

Disadvantages of Naive Bayes

  1. If your test data set has a categorical variable of a category that wasn’t present in the training data set, the Naive Bayes model will assign it zero probability and won’t be able to make any pred...
  2. This algorithm is also notorious as a lousy estimator. So, you shouldn’t take the probability outputs of ‘predict_proba’ too seriously.
  1. If your test data set has a categorical variable of a category that wasn’t present in the training data set, the Naive Bayes model will assign it zero probability and won’t be able to make any pred...
  2. This algorithm is also notorious as a lousy estimator. So, you shouldn’t take the probability outputs of ‘predict_proba’ too seriously.
  3. It assumes that all the features are independent. While it might sound great in theory, in real life, you’ll hardly find a set of independent features.

Applications of Naive Bayes Algorithm

  • As you must’ve noticed, this algorithm offers plenty of advantages to its users. That’s why it has a lot of applications in various sectors too. Here are some applications of Naive Bayes algorithm: 1. As this algorithm is fast and efficient, you can use it to make real-time predictions. 2. This algorithm is popular for multi-class predictions. You can find the probability of multiple target cl…
See more on upgrad.com

Conclusion

  • We hope you found this article useful. If you have any questions related to the Naive Bayes algorithm, feel free to share them in the comment section. We’d love to hear from you. If you’re interested to learn more about AI, machine learning, check out IIIT-B & upGrad’s PG Diploma in Machine Learning & AIwhich is designed for working professionals and offers 450+ hours of rig…
See more on upgrad.com