D204 Practice Exam Questions Well Answered.

Business Understanding/ Discovery phase - Answer An analyst defines the major questions of interest that need to be answered, determines the needs of the stakeholders, and assesses the resource constraints of the project. Define project outcomes. Data Acquisition - Answer Collecting data phase. Data is collected and stored, for easy retrieval from a database, perhaps a component of a data warehouse, by using a language like SQL. Web scraping and surveys to acquire data. Data Cleaning - Answer Also known as data cleansing, data wrangling, data munging, and feature engineering. Analyst will use SQL, Python, R, or Excel to perform data modifications and transformations Data Exploration - Answer Analyst begins to understand the basic nature of data, the relationships within it (btw data variables), the structure of the dataset, the presence of outliers, and the distribution of data values. This phase uses data visualization tools and numerical summaries such as measures of central tendency and variability. Predictive Modeling - Answer Allows the analyst to move beyond describing the data to creating models that enable predictions of outcomes of interest. Python and R are used in automating the training and use of models. Data Mining - Answer Looks for patterns in large sets of data. Tools are Python and R. Also called Machine learning. A specialized segment of data mining techniques that continually update to improve modeling over time. Data Exploration - Answer An initial step to uncover initial patterns and using both manual and automated methods. Data Mining - Answer An in- depth step to discover patters using automated methods like machine learning. Data Reporting - Answer Analyst tells the story