We all know that machine learning is a huge and growing field. But where do you start if you want to learn more about it? Here are 10 basic topics that every machine learning enthusiast should know.
For more information check out our video:
Introduction to Machine Learning
Machine learning is a branch of artificial intelligence that deals with the design and development of algorithms that can learn from data and make predictions. It has become one of the hottest topics in recent years, with a growing number of businesses and organizations using it to extract valuable insights from data.
There are a number of different machine learning techniques, but some of the most popular include supervised learning, unsupervised learning, and reinforcement learning. In supervised learning, algorithms are trained on a dataset with known labels (i.e. inputs and outputs); in unsupervised learning, algorithms are trained on a dataset without known labels; in reinforcement learning, algorithms are trained by interacting with an environment and receiving feedback.
Some machine learning tasks are easier than others; for example, regression (predicting continuous values) is typically easier than classification (predicting discrete values). Some machine learning problems are also easier to solve than others; for example, problems with small datasets are typically easier to solve than problems with large datasets.
If you’re new to machine learning, here are 10 basic topics you should know:
1. Supervised Learning
2. Unsupervised Learning
3. Reinforcement Learning
6. Anomaly Detection
8. Dimensionality Reduction
9. Feature Engineering
10. Model Selection
In supervised learning, the aim is to build a model that makes predictions based on previously seen data. This is done by training the model on a dataset where the correct answers are already known.
There are two main types of supervised learning:
-Classification: The aim is to predict a class label (e.g. “spam” or “not spam”). This is typically done by training a model to output probabilities for each class, and then making predictions based on which class has the highest probability.
-Regression: The aim is to predict a continuous value (e.g. the price of a house). This is typically done by training a model to output a value for each example, and then making predictions based on the average of these values.
Supervised learning can be further divided into three main types of problems:
-Binary classification: The output can only be one of two classes (e.g. “spam” or “not spam”).
-Multiclass classification: The output can be one of more than two classes (e.g. gender prediction might have classes “male”, “female” and “other”).
-Regression: The output is a continuous value (e.g. predicting the price of a house).
In simple terms, unsupervised learning is the ability to find patterns in data. As the name suggests, it is a method of machine learning that does not require labels or other forms of supervision.
Some common unsupervised learning algorithms include:
-Clustering: This algorithm groups similar data points together. Common clustering algorithms include k-means clustering and hierarchical clustering.
-Dimensionality Reduction: This algorithm reduces the number of features in a dataset while retaining important information. Common dimensionality reduction algorithms include principle component analysis (PCA) and linear discriminant analysis (LDA).
-Association Rules: This algorithm finds relationships between items in a dataset. A common association rule algorithm is the Apriori algorithm.
Reinforcement learning is a type of machine learning that is concerned with how software agents ought to take actions in an environment so as to maximize some notion of cumulative reward. The agent receives rewards by taking the correct actions and punishments for taking the wrong actions.
Dimensional reduction is a method used to reduced the volume of data, typically by finding underlying patterns in the data. This can be done through a number of methods, including:
-Principal component analysis (PCA)
-Independent component analysis (ICA)
-Singular value decomposition (SVD)
-Non-negative matrix factorization (NMF)
Each of these methods has its own strengths and weaknesses, so it’s important to understand when to use each one. For example, PCA is often used for data visualization, while SVD is more useful for recommendation systems.
Dimensionality reduction is a powerful tool for understanding and working with high-dimensional data. It can help you find hidden patterns, reduce noise, and make your data more manageable.
Model Selection and Tuning
In machine learning, model selection and tuning is the process of choosing the best model for a given task from a set of candidate models. The goal is to find a model that performs well on unseen data. This is usually done by optimizing a performance metric such as accuracy or log-loss.
There are a few different ways to approach model selection and tuning. One common method is to use cross-validation. This involves splitting the data into train and test sets, training the model on the train set, and then evaluating it on the test set. The model with the best performance on the test set is chosen as the final model.
Another common method is to use a separate validation set. This is similar to cross-validation, but instead of using the test set for evaluation, a separate validation set is used. The model with the best performance on the validation set is chosen as the final model.
Once a final model has been selected, it may still need to be tuned. This can be done by optimize one or more hyperparameters of the model. For example, if you are using a Support Vector Machine (SVM) for classification, you may want to optimize the value of C (a hyperparameter of SVMs) to get the best performance on your data.
Model selection and tuning can be challenging because it can be difficult to know when you have found the best model. One way to assess whether your currentmodel is good enough is to compare it to a simple baselinemodel. A baselinemodel is one that always predicts the most common class label (for classification tasks) or mean value (for regression tasks). If your currentmodel outperforms the baselinemodel by a significant margin, then it is likely that you have found a good model.
Data pre-processing is a data mining technique that involves transforming raw data into an understandable format.pre-processing techniques are used to make data more trustworthy, easier to work with, and easier to understand.
There are several ways to pre-process data, but the most common methods are Data Cleaning, Data Transformation, Data Aggregation, and Data Reduction.
Data cleaning is the process of identifying and removing inaccuracies and inconsistencies from data. This step is important because it can improve the quality of your data and make it more useful for downstream tasks such as machine learning.
Data Transformation is the process of converting data from one format to another. This can be useful for making data more compatible with a particular machine learning algorithm or for making it more human-readable.
Data aggregation is the process of combining multiple pieces of data into a single summary. This can be useful for reducing the size of your data set or for increasing its overall comprehensibility.
Data reduction is the process of reducing the dimensionality of your data while retaining as much information as possible. This can be done using a variety of methods, such as feature selection or feature extraction.
In machine learning, feature engineering is the process of transforming raw data into features that better represent the underlying problem to the predictive models, resulting in improved model accuracy.
The idea is to come up with features that are more likely to be predictive of the target variable. This process usually requires a significant amount of domain knowledge and visual exploration to find the right transformation. In many cases, feature engineering will also involve creating new features by combining multiple existing features.
Some common examples of feature engineering include:
-String parsing and pattern matching (e.g., extracting titles from names or matchng street addresses)
-Encoding categorical variables as numeric indices (e.g., country codes or product IDs)
-Discretization of continuous variables (e.g., age groupings or income ranges)
-Creating interaction terms between features (e.g., product purchased with or without insurance)
-Calculating derived quantities from raw data (e.g., time since last purchase or total spend on a website)
Ensemble methods are machine learning techniques that combine multiple models to achieve better accuracy. Ensemble methods can be used for classification or regression. Some popular ensemble methods include:
-Bootstrap Aggregation (Bagging)
-Gradient Boosted Machines
Deep learning is a subfield of machine learning that is a set of algorithms that attempt to model high-level abstractions in data by using a deep graph with many layers of processing nodes.
Keyword: 10 Basic Machine Learning Topics You Should Know