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Machine Learning Guide: A Beginner’s Path to Mastery
jeudi 15 août 2024, 11:57 , par eWeek
Machine learning (ML) uses advanced mathematical models known as algorithms to improve artificial intelligence tools by helping them analyze and comprehend data, letting them “learn” from that data to continuously improve their performance. ML uses a variety of techniques to facilitate artificial intelligence tasks such as natural language processing (NLP), image recognition, and predictive analytics. Continuous learning and adaptation promote innovation and transformation across multiple industries.
KEY TAKEAWAYS Machine learning is a type of artificial intelligence that analyzes and processes data to help humans make data-driven decisions. (Jump to Section) Machine learning involves collecting, processing, training, tuning, evaluating, visualizing, and deploying data in a model form. (Jump to Section) The data used for machine learning may come from public or proprietary datasets, crowdsourced data, synthetic data, or data from open government initiatives. (Jump to Section) TABLE OF CONTENTS ToggleWhat is Machine Learning?How Do Machine Learning Systems Work?Components of a Machine Learning Model7 Types of Machine LearningMachine Learning Frameworks and MethodsSources of Training Data for Machine LearningIndustry Machine Learning Use CasesEthical and Legal Concerns in Machine LearningFAQBottom Line: Machine Learning Will Keep Getting Easier and Better to Use What is Machine Learning? Machine learning refers to the use of advanced mathematical models, or algorithms, to process large volumes of data and gain insight without direct human instruction or involvement. A subset of artificial intelligence (AI) built on artificial neural networks (ANNs) or simulated neural networks (SNNs)—essentially node layers that interact and interconnect—it also includes a specialized type of machine learning called deep learning (DL). Machine learning mimics the way humans learn. It spots patterns and then uses the data to make predictions about future behavior, actions, and events. It uses new data to constantly adapt, changing its actions as necessary. This ability to learn from experience separates it from static tools like business intelligence (BI) and conventional data analytics. Organizations across industries are turning to ML to address complex business challenges. The technology is particularly valuable in fields like marketing and sales, financial services, healthcare, retail, energy, transportation, and government planning. How Do Machine Learning Systems Work? Machine learning enables computers to learn from data and make judgments without requiring explicit programming using a number of key steps from data collection to model deployment. Data Collection Data collecting is a key step in developing a machine learning system that involves gathering data from multiple sources relevant to the problem you wish to address. This data might originate from a variety of sources, including sensors, databases, user interactions, and web scraping. The quality and quantity of data gathered have a significant impact on the effectiveness of the machine learning model—for example, if you’re creating a model to recognize cat photographs, you’ll need a broad range of cat images to train it efficiently. Data Preprocessing Once data has been acquired, it typically has to be cleaned and formatted before being analyzed. This includes deleting duplicates, resolving missing values, and normalizing or scaling numerical data. Preprocessing is necessary since raw data is rarely in ideal condition for analysis. For example, if you’re working with text data, you may need to remove punctuation and convert all text to lowercase to maintain consistency. Preprocessing converts data into a format more suited for input into a machine learning model. Data Modeling Data modeling is the process of selecting and building a machine learning algorithm to generate predictions or judgments based on data. There are several models to choose from, including regression models, decision trees, and neural networks—the type is determined by the nature of the data and the problem to be solved. For example, a linear regression model might be used to estimate property values based on factors such as location and size, but a convolutional neural network (CNN) is more suited for image classification tasks. Data Training Data training is the process of introducing preprocessed data into a machine learning model to learn from the data. During this phase, the model updates its internal parameters to reduce inaccuracy in predictions. This technique necessitates separating the data into training and validation sets. The training set is used to educate the model, while the validation set is used to assess its performance. Over time, the model learns patterns and correlations in the data, allowing it to make more accurate predictions. Hyperparameter Tuning Tuning, also known as hyperparameter tuning or optimization, is the process of altering a model’s hyperparameters to improve its performance. Hyperparameters are settings that influence the learning process, such as the learning rate, the number of layers in a neural network, or the maximum depth of a decision tree. Fine-tuning these parameters can greatly improve the model’s accuracy and efficiency. Grid search and random search are two widely used techniques for determining the optimal combination of hyperparameters. Performance Evaluation The evaluation analyzes how well the trained model works on previously unknown data, known as the test set. Depending on the task, this step involves monitoring a variety of performance indicators, including accuracy, precision, recall, and F1 score. Evaluation determines how effectively the model generalizes to new data and detects possible problems, such as overfitting or underfitting. Overfitting occurs when the model performs well on training data but badly on fresh data, whereas underfitting occurs when the model is overly simplistic to capture the underlying patterns in the data. Data Visualization Data visualization is the process of displaying the machine learning model’s outputs in an understandable format. This might involve creating graphs, charts, and heatmaps to demonstrate performance data, feature relevance, or forecasts. Visualization assists in interpreting results, identifying trends, and communicating findings to stakeholders. For example, a confusion matrix may be used to visualize a classification model’s performance by displaying the number of accurate and wrong predictions. Model Deployment Model deployment is the act of putting a trained model into a production environment so that it can forecast fresh data in real time. This involves setting up the appropriate infrastructure, such as servers and APIs, to allow the model to communicate with users or other systems. Deployment also requires evaluating the model’s performance in the actual world and making necessary adjustments. For example, an e-commerce site’s recommendation system regularly suggests products to consumers based on their browsing history. Components of a Machine Learning Model Machine learning frameworks use software languages such as TensorFlow and PyTorch to deliver a usable model. A machine learning model involves three distinct components: Decision Process: A system ingests data and uses a machine learning algorithm to classify and predict events. Error Function: This built-in capability allows the model to evaluate the accuracy and quality of predictions. Model Optimization Process: This feature allows ML models to adapt by finding data that’s a better fit with the training set—as the model changes, the system continues to evaluate and refine itself to achieve accuracy goals. 7 Types of Machine Learning There are seven types of ML, each with its own special characteristics and applications that help it develop and enhance data prediction capabilities. Using them can help manage large data production and manage datasets. Supervised Learning In supervised learning, machines are trained on labeled datasets so that systems can predict outputs based on their training data. Each training sample contains input-output pairings, which allow the model to learn the mapping between inputs and outputs. This method is commonly used in classification and regression tasks such as spam detection, image recognition, and predictive maintenance. Unsupervised Learning Unsupervised learning works with unlabeled data. The system attempts to find patterns and relationships in the data without prior knowledge of the results. Common strategies include clustering (grouping related data points) and association (finding rules that describe large portions of the data). Applications include customer segmentation, anomaly detection, and market basket analysis. Semi-Supervised Learning Semi-supervised learning is a technique that combines parts of supervised and unsupervised learning. It combines a small set of labeled data with a much larger pool of unlabeled data. This method is especially beneficial when labeling data is expensive or time-consuming because it allows you to make the most of copious unlabeled data to improve the model’s accuracy. Semi-supervised learning is commonly used in online content categorization and medical imaging analysis when acquiring labeled data is difficult but unlabeled data is freely available. Reinforcement Learning Reinforcement learning is based on trial and error, in which an agent interacts with its environment to gather information and make decisions. The agent is rewarded or penalized based on its activities and learns to optimize cumulative rewards over time. This type is very useful in circumstances that involve sequential judgments, such as gameplay, robotic control, and autonomous driving. Self-Supervised Learning Self-supervised learning uses unsupervised approaches to solve issues that traditionally need supervised learning. Rather than using explicit labels, it produces implicit labels from unstructured input, allowing the model to learn representations and characteristics independently. This approach is gaining popularity in disciplines such as natural language processing (NLP) and computer vision, where pre-training models on large datasets may significantly improve their performance. Online Machine Learning Online machine learning allows models to learn progressively from a continuous stream of data points in real-time. The model’s parameters are continuously updated as new data arrives, allowing it to adapt to changing situations and make real-time predictions. Applications include fraud detection, real-time recommendation systems, and adaptable user interfaces. Batch Learning Batch learning involves training models on large amounts of accumulated data. The algorithm does not update its parameters until the full batch has been processed, which requires a significant amount of computing resources such as CPU, RAM, and disk I/O. This method is suitable for circumstances where the data changes infrequently, such as offline predictive modeling and large-scale data processing. Machine Learning Frameworks and Methods Machine learning revolves around several core algorithmic frameworks to achieve results and produce models that are useful, including neural networks, linear and logistic regression, clustering, decision trees, and random forests. Neural Networks Neural networks are artificial intelligence algorithms designed to simulate the way the human brain thinks. They use training data to spot patterns and typically learn rapidly, using thousands or even millions of processing notes. They’re ideal for recognizing patterns and are widely used for speech recognition, natural language processing, image recognition, consumer behavior, and financial predictions. Linear Regression The technique identifies relationships between independent input variables and at least one target variable. Valuable for predicting numerical values, such as prices for airline flights or real estate values—usually over a period of weeks or months—it can display predicted price or value increases and decreases across a complex dataset. Linear regression graph showing the relationship between two variables. Logistic Regression This method typically uses a binary classification model (such as “yes/no”) to tag or categorize whether an event is likely to occur. It sorts through a dataset to find weights and biases that can be built into or excluded from the model. A common use for this technology is identifying spam in email and blacklisting unwanted software code or malware. A nonlinear polynomial regression graph showing a relationship between independent and dependent variables. Clustering This ML tool uses unsupervised learning to spot patterns and relationships that humans may overlook. An example of clustering is how a supplier performs for the same product at different facilities. This approach could be used in healthcare to understand how different lifestyle conditions impact health and longevity. It can also be used for trend detection on websites and in social media, such as determining what text, images, and video to display. Decision Tree The supervised learning approach builds a data structure with nodes that test an idea or concept against a set of input data. A decision tree delivers numerical values but also performs some classification functions to help users visually understand data. Unlike other forms of ML, it makes it possible to review and audit results. In the business world, decision trees are often used to develop insights and predictions about downsizing or expanding, changing a pricing model, or succession planning. A type of decision tree algorithm known as a classification tree. Random Forest A random forest model incorporates multiple decision tree models simultaneously. Combining decision trees makes it possible to classify categorical variables or the regression of continuous variables, forming what’s called an ensemble. This makes it possible to use different trees to produce specific predictions but then combine the predictions into a single ensemble or overall model. A random forest algorithm ML tool might be used for a recommendation system, for example. Sources of Training Data for Machine Learning Training data is an important part of machine learning. When choosing data sources, consider data quality, relevance to your unique use case, and any legal or ethical considerations of using the data. Public Datasets Public datasets are often shared by schools, hospitals, organizations, researchers, or government bodies to promote transparency and facilitate research. They usually cover a wide range of topics and are shared under open licenses such as Creative Commons that lets them be reused with certain conditions. Some common public dataset sources include the following: Kaggle: A diverse collection of datasets for fields like healthcare, finance, and natural language processing, Kaggle organizes competitions to provide more context and organization for data use. UCI Machine Learning Repository: The University of California, Irvine’s School of Information and Computer Sciences offers datasets for classification, regression, and clustering with extensive descriptions and benchmarks. Google Dataset Search: Google Dataset Search aggregates datasets from various platforms and repositories, making them easily accessible to users. Academic Repositories: Universities and research labs frequently share datasets as part of their publications and projects. Proprietary Datasets Private entities often own proprietary datasets that can be purchased or licensed. Costs vary widely based on the dataset’s size, quality, and exclusivity. These datasets are usually customized to specific industries or applications, making them valuable for particular use cases in machine learning and data science. Some common proprietary dataset sources include the following: Company-Specific Data: Companies may collect private data from user interactions, transactional records, or IoT sensors. Commercial Data Providers: Commercial data providers such as Nielsen and Experian offer large and carefully curated datasets for purchase. Crowdsourced Data Crowdsourced data is collected from a large and diverse group of people using a variety of approaches. While the quality of this data may vary, the variety can be beneficial to machine learning. The multiplicity of inputs allows the system to identify correlations and create a complete dataset that can be used to design robust models. Some common sources of crowdsourced data include the following: Amazon Mechanical Turk: Amazon Mechanical Turk crowdsourcing marketplace allows the collection of labeled data by distributing tasks to a greater number of people. It is useful for tasks that need human decisions such as image annotation or sentiment analysis. Social Media Forums: Social media and other online forums collect data that can be used to gather opinions, identify trends, and analyze the way users interact with a certain social topic for use in sentiment analysis, trend prediction, and other social analytics that can be used either in marketing or product development. Synthetic Data Synthetic data is mock data used to simulate real-world data. It is generated through an algorithm and is only used if real-world data is limited or scarce, or if privacy concerns are an issue. Techniques such as generative adversarial networks (GANs) and other data augmentation methods are used to fully simulate the data required. Industry Machine Learning Use Cases Machine learning has transformed a variety of businesses by allowing for data-driven decision-making, automating processes, and uncovering previously unknown insights across such sectors as energy, insurance, FinTech, healthcare, marketing, and more. Here are some of the most common use cases: Energy Industry: Machine learning is used to optimize production, distribution, and consumption, helping schedule predictive maintenance and manage energy load control. Algorithms can examine sensor data to identify equipment problems before they occur to minimize downtime and maintenance costs, and help balance grid supply and demand by predicting consumption trends and modifying distribution. Insurance: Machine learning is used to analyze risk, identify fraud, and provide customized policy recommendations by evaluating past data. Models can anticipate the likelihood of claims and detect fraudulent activity, allowing providers to offer more precise pricing and decrease losses due to fraud. FinTech and Banking: In fintech and banking, ML improves fraud detection, client service, and customized financial advice by using algorithms to evaluate transaction patterns to identify abnormalities and avoid fraud. ML-driven chatbots provide quick customer service, resolving simple requests while freeing up human agents to handle more complicated situations. Healthcare: Machine learning can improve radio imaging diagnosis and help personalize treatment plans by analyzing patient data, resulting in more effective and specific healthcare treatments. It improves hospital operations by anticipating patient admissions, resource requirements, and scheduling, helping increase productivity and better patient care. Public Sector: Predictive analytics can aid in crime prevention by identifying possible hotspots and efficiently deploying resources, while traffic management systems monitor traffic flow and alleviate congestion. ML models also examine data sources to forecast and manage the effects of natural disasters to increase preparedness and response efforts. Customer Support: Machine learning improves customer support by automating replies, increasing customer happiness, and lowering operating expenses. Chatbots and virtual assistants answer common questions, freeing up human agents to work on more complicated situations that require their expertise. Sales: Sales teams can use ML to predict client behavior, optimize pricing strategies, and improve lead scoring. ML algorithms predict future sales patterns, propose ideal pricing, and find high-potential prospects by analyzing previous sales data—this improves sales revenue by concentrating efforts on the most promising opportunities and pricing products competitively in response to market demand and consumer behavior trends. Marketing: Marketers use machine learning to customize ads, forecast potential trends, and optimize ad spend. Client data is analyzed to generate personalized marketing campaigns, predict future market trends, and better allocate advertising expenses, increasing ROI with more targeted marketing. Employee Retention: ML can identify characteristics that contribute to staff turnover and provide retention solutions by examining employee data to predict which employees are likely to leave and offer actions to increase job satisfaction and retention. This involves finding trends in job satisfaction, work-life balance, and career advancements, helping organizations solve concerns about increasing employee retention. Ethical and Legal Concerns in Machine Learning Ethical usage of ML should prioritize informed consent, anonymity, fairness, and openness. Legally complying with data protection regulations, avoiding breaches, preserving the right to be forgotten, and managing cross-border data transfers are all important, and balancing innovation with these challenges is key to the appropriate and legal application of this technology. Data Privacy Issues Regulations such as the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) set rigorous requirements for managing personal data, with severe penalties for noncompliance. Organizations must secure their data against breaches since the legal repercussions include large penalties and reputational harm. Individuals can seek data deletion under laws requiring machine learning models that might be technically complex. Also, data transfer across borders is legally problematic due to the differences in data protection legislation between jurisdictions. Bias and Fairness Bias in machine learning models can result in unfair treatment of individuals based on their ethnicity, gender, or other attributes. Maintaining fairness necessitates ongoing monitoring and modifications to prevent perpetuating current inequities. To provide equal outcomes for all users, varied datasets and algorithms capable of detecting and mitigating bias must be used. Accountability and Transparency Machine learning systems must be responsible and transparent to foster confidence and assure ethical activities. This includes explicitly documenting how models are created, trained, and assessed, as well as explaining their judgments. Transparency enables stakeholders to understand and debate the findings of machine learning systems, promoting more accountability in their implementation. Regulatory Frameworks As machine learning technology evolves, so do the regulatory frameworks governing its use. Emerging regulations aim to address the ethical and legal challenges associated with AI and machine learning, providing guidelines and standards for responsible use. Organizations must stay informed about these regulations and ensure compliance to avoid legal issues and maintain public trust. FAQ How Much Data is Needed to Train a Machine Learning Model? The quality of data needed to train a machine learning model varies according to the problem’s complexity, model used, and desired accuracy. Complex issues like image classification sometimes require large datasets, potentially in the tens of thousands. In contrast, simpler tasks may need fewer data points. More complex models such as deep neural networks typically require more data to reach peak performance, but simpler models, such as linear regression, may perform well with less data. Additionally, a common guideline is to have at least 10 times as many data points as features and higher accuracy demands often translate to the need for more data. What are the Golden Rules of Machine Learning? Maintaining a strong data pipeline, defining clear and realistic goals, starting with simple features, and regularly assessing and maintaining model performance are all important golden rules for effective machine learning. To minimize overfitting, infrastructure should be tested separately from machine learning models using approaches such as cross-validation. Adhering to these guidelines helps to guarantee that the model works effectively and is reliable over time. What’s the Difference Between AI and ML? AI is a broad field that includes a variety of approaches designed to simulate human intelligence, including reasoning and problem-solving. This encompasses subfields such as natural language processing and robotics. ML is a subfield of AI that focuses on building algorithms that allow computers to learn from and predict data. While ML is a type of AI, not all AI is based on ML. Bottom Line: Machine Learning Will Keep Getting Easier and Better to Use The rapid advancement of ML technology ensures that it will play an increasingly prominent role in defining business in the years to come, affecting industries as diverse as agriculture, finance, manufacturing, transportation, marketing, customer support, and cybersecurity. Machine learning will also help drive corporate environmental, social, and governance (ESG) programs and sustainability initiatives that affect sourcing, supply chains, and Scope 3 emissions that extend back to raw materials and component providers. Machine learning systems are becoming easier to use and manage. As a result, they are extending deeper into organizations and moving beyond the scope of data scientists. As organizations look to trim costs, boost productivity, oversee ESG programs, build smart factories, better manage supply chains, and fuel innovation at scale, ML will continue to emerge as an essential tool. Read our guide to AI and ethics to learn more about the implications posed by this dynamic and powerful technology. The post Machine Learning Guide: A Beginner’s Path to Mastery appeared first on eWEEK.
https://www.eweek.com/artificial-intelligence/machine-learning/
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