DS Unit - 4

Unit-IV: 

Introduction to Research Methodology, Literature survey and referencing, Problem  formulation, Data preparation, Managing Big data with Hadoop and SPARK 


Introduction to Research Methodology


Research methodology in data science refers to the process of conducting scientific research to gather and analyze data, and draw meaningful conclusions from the data. Research methodology involves several steps, including the formulation of research questions, the design of research studies, the collection and analysis of data, and the interpretation of results.


In data science, research methodology is used to study various phenomena, such as consumer behavior, market trends, and the performance of machine learning algorithms. The following are the key components of research methodology in data science:


Research Questions: This involves defining research questions and hypotheses that will guide the research study. The research questions should be clear, specific, and answerable through the analysis of data.


Research Design: This involves the selection of appropriate research design and data collection methods, such as surveys, experiments, and case studies. The research design should be tailored to the research questions and hypotheses.


Data Collection: This involves the collection of data through various sources, such as surveys, interviews, and observations. The data collection methods should be reliable, valid, and representative of the research population.


Data Analysis: This involves the analysis of data using appropriate statistical methods and techniques. Data analysis should be objective, systematic, and transparent.


Results Interpretation: This involves interpreting the results of the data analysis and drawing meaningful conclusions. The interpretation of results should be based on evidence and supported by the data.


Research methodology is an important component of data science, as it ensures that data scientists use rigorous and systematic approaches to gather and analyze data. By using research methodology, data scientists can ensure that their findings are valid, reliable, and meaningful, and can be used to make informed decisions and drive business strategy.



Literature survey and referencing


Literature survey and referencing are important components of data science research. Literature survey involves conducting a comprehensive review of existing literature on a particular topic, in order to identify relevant studies, theories, and concepts that can inform the research study. Referencing involves citing the sources of information used in the research study, in order to give credit to the original authors and to enable readers to locate the sources themselves.


The following are the key steps involved in conducting a literature survey and referencing in data science:


Identifying relevant sources: The first step in conducting a literature survey is to identify relevant sources of information, such as academic journals, conference proceedings, books, and online databases. This can be done through a variety of methods, including keyword searches, citation tracking, and expert recommendations.


Evaluating sources: Once the relevant sources have been identified, they should be evaluated to determine their relevance, quality, and credibility. This involves assessing the methodology, scope, and findings of each source, and determining how they relate to the research study.


Organizing sources: After evaluating the sources, they should be organized in a way that makes it easy to access and review the information. This can be done through tools such as reference management software, which allows users to store and organize references in a database.


Referencing sources: In order to give credit to the original authors and enable readers to locate the sources themselves, all sources used in the research study should be referenced. This involves citing the author, title, publication date, and other relevant information, in accordance with the appropriate citation style.


Literature survey and referencing are important components of data science research, as they help to ensure that the research study is informed by relevant and credible sources, and that the information used in the study is properly attributed to the original authors. By conducting a comprehensive literature survey and referencing their sources properly, data scientists can demonstrate the rigor and credibility of their research, and contribute to the advancement of knowledge in their field.



 Problem  formulation, Data preparation


Problem formulation and data preparation are critical steps in the data science process. These steps involve defining the problem to be solved, identifying the relevant data sources, and preparing the data for analysis.


Problem Formulation: The first step in any data science project is to formulate the problem to be solved. This involves defining the research question or problem statement, and determining the scope and objectives of the project. The problem formulation should be specific, measurable, and aligned with the goals of the organization or stakeholders.


Data Collection: Once the problem has been formulated, the next step is to identify the relevant data sources. This can involve collecting data from internal databases, external sources such as social media or web scraping, or conducting surveys or experiments to collect new data. It is important to ensure that the data collected is relevant, reliable, and valid for the research question.


Data Cleaning: After the data has been collected, it needs to be cleaned and preprocessed to remove any errors or inconsistencies. This involves checking for missing data, removing duplicates, and correcting any errors in the data. It is important to ensure that the data is clean and consistent before proceeding with the analysis.


Data Integration: Data may come from multiple sources and may need to be integrated to create a complete dataset. This involves matching data from different sources based on common variables or creating new variables that combine information from multiple sources.


Data Transformation: Data may need to be transformed to make it suitable for analysis. This can involve converting data into different formats, aggregating data, or creating new variables based on existing ones.


Data Reduction: In some cases, the amount of data may be too large to analyze effectively. Data reduction techniques such as sampling, feature selection, or dimensionality reduction can be used to reduce the size of the dataset while preserving important information.


Proper problem formulation and data preparation are crucial for the success of any data science project. By defining the problem to be solved and preparing the data for analysis, data scientists can ensure that the analysis is accurate, reliable, and meaningful.



Managing Big data with Hadoop and SPARK


Hadoop and Spark are two popular tools for managing big data in data science.


Hadoop is an open-source framework for storing and processing large data sets across a distributed network of computers. It is based on the MapReduce programming model, which involves breaking down large data sets into smaller chunks and processing them in parallel. Hadoop provides a distributed file system (HDFS) for storing data and a set of tools for processing data, including MapReduce, Pig, and Hive. Hadoop can handle a wide variety of data types, including structured, unstructured, and semi-structured data.


Spark is another open-source framework for processing large data sets. It is designed to be faster and more efficient than Hadoop, and can handle both batch processing and real-time data processing. Spark is based on the concept of Resilient Distributed Datasets (RDDs), which are distributed data sets that can be processed in parallel across a cluster of computers. Spark provides a set of APIs for processing data, including Spark SQL, Spark Streaming, and Spark MLlib.


When managing big data with Hadoop and Spark, data scientists typically follow these steps:


Data ingestion: This involves bringing in data from various sources and storing it in a distributed file system like HDFS.


Data processing: This involves processing the data using tools like MapReduce or Spark to perform tasks like cleaning, transforming, and aggregating data.


Data analysis: This involves using tools like Pig, Hive, or Spark SQL to analyze the processed data and extract insights.


Data visualization: This involves using tools like Tableau or D3.js to create visualizations of the analyzed data.


Model building: This involves using tools like Spark MLlib or Hadoop Mahout to build predictive models using the analyzed data.


Deployment: This involves deploying the models in production environments to make predictions on new data.


Hadoop and Spark have revolutionized the way big data is managed and analyzed. By allowing data scientists to process and analyze large data sets in a distributed and parallel manner, these tools have enabled organizations to gain valuable insights from their data and make data-driven decisions.


No comments:

Post a Comment