Lecturer3 by RamaKrishna SRU waranagal telanga

coolscools1231 11 views 17 slides Sep 11, 2024
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About This Presentation

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Data Mining Techniques Data mining techniques refer to the methods and algorithms used to analyze large datasets and extract meaningful patterns, trends, and relationships from the data. These techniques help to turn raw data into valuable information that can be used for decision-making, predictions, and understanding complex patterns.

Purpose of Data Mining Techniques Extract Patterns : Identify hidden patterns, relationships, and insights from large datasets that are not immediately obvious. Make Predictions : Use historical data to make predictions about future events or behaviors. Classify Data : Organize data into categories or classes based on certain criteria. Identify Anomalies : Detect unusual or unexpected data points that deviate from the norm. Simplify Data : Reduce the complexity of data by finding key features or dimensions that represent the data well.

How Data Mining Techniques Work Data Preparation : Before applying any technique, data needs to be cleaned, transformed, and prepared. This includes handling missing values, removing noise, and normalizing data. Algorithm Application : The chosen technique or algorithm is then applied to the dataset to identify patterns, build models, or make predictions. Model Evaluation : The performance of the model or technique is evaluated using metrics like accuracy, precision, recall, and others, depending on the task. Interpretation : Finally, the results are interpreted and translated into actionable insights.

Data Mining Techniques Classification : Predicting categorical labels based on input data. Clustering : Grouping similar data points together. Regression : Predicting numerical values. Association Rule Mining : Finding relationships between variables in large datasets. Anomaly Detection : Identifying unusual data points.

Supervised and Unsupervised learning Supervised and unsupervised learning are two primary approaches in machine learning that differ based on the nature of the input data and the learning process.

Supervised Learning Definition: In supervised learning, the model is trained on a labeled dataset, meaning that each input data point is associated with a corresponding output label or target value. The goal is for the model to learn a mapping from inputs to outputs so that it can predict the output for new, unseen data.

How It Works: The training data consists of input-output pairs (e.g., 𝑋 and 𝑦). The model learns by minimizing the difference between the predicted output and the actual output. Once trained, the model can predict the output for new input data.

Examples of Supervised Learning Algorithms Classification: Decision Trees, Support Vector Machines (SVM), k-Nearest Neighbors (k-NN), Naive Bayes. Regression: Linear Regression, Logistic Regression, Ridge Regression. Applications Email Spam Detection: Classify emails as spam or not spam. Medical Diagnosis: Predict if a patient has a certain disease based on medical data. Fraud Detection : Identify fraudulent transactions based on historical labeled data

Advantages Highly accurate predictions if sufficient labeled data is available. The relationship between inputs and outputs is explicitly modeled. Challenges Requires a large amount of labeled data, which can be costly and time-consuming to obtain. The model may not generalize well to unseen data if the training data is biased.

Unsupervised Learning Definition: In unsupervised learning, the model is trained on data without explicit labels or targets. The goal is to discover hidden patterns, structures, or relationships in the data without prior knowledge of the outcomes.

How It Works: The training data consists of only inputs (e.g., 𝑋) with no associated outputs. The model tries to find patterns, such as grouping similar data points together or reducing the dimensionality of the data. The output is often a set of clusters or simplified representations of the data.

Examples of Supervised Learning Algorithms Clustering: k-Means, Hierarchical Clustering, DBSCAN. Dimensionality Reduction : Principal Component Analysis (PCA), t-SNE, Autoencoders. Association : Apriori , FP-Growth (used for finding associations between items in a dataset). Applications Customer Segmentation : Group customers based on purchasing behavior without predefined labels. Anomaly Detection : Identify outliers in network traffic or financial transactions. Recommendation Systems : Discover patterns in user behavior to suggest products or content.

Advantages Can work with unlabeled data, which is often easier to collect. Useful for exploratory data analysis and discovering hidden patterns. Challenges The results may be less interpretable since there are no labels to guide the learning. It's harder to evaluate the performance of the model because there are no predefined correct answers.
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