Reasons for Messy Data and Anomalies in Data Science
The reasons for messy data and anomalies in data science can vary widely and are often the result of various factors. Here are some common reasons and potential cures for both messy data and anomalies:
Why the data is messy:
1. Data Collection Errors: Typographical errors, missing numbers, and wrong data entry can all mess up the data collected. These mistakes can happen when data is entered by hand or when data is extracted automatically.
Fix: Use validation of data and cleaning methods while collecting data to cut down on mistakes. Check for mistakes and missing numbers by using validation of information rules and automated tools.
2. Integration Problems with Data: When data is gathered from many different places or systems, integration problems can happen. Different ways of storing data, naming it, and putting it together may leave the data messy.
Standardize the way data is stored and how it is named during data integration. Use ETL (Extract, Transform, Load) methods to clean and change data from different sources into a common format.
3. Incomplete Data: Sometimes, data isn't complete because some observations didn't have all of the areas filled out or recorded.
Fix: Carefully consider how important the missing data is and think about solutions like estimation (guessing missing values based on the data you have) or using statistical techniques that can deal with missing data.
Reasons for Anomalies:
1. Data Entry Errors: Abnormalities can happen when the wrong numbers are entered for some observations because of a data entry error.
Fix: Use data validation checks when entering data to catch mistakes as soon as possible. You might want to use methods like outlier identification to find possible problems.
2. Real outliers: Anomalies can also be real data points that show rare events or big changes from the norm.
Cure: Based on the situation, you may want to look into and figure out why real exceptions exist. They may give you important information or tell you that your research needs to be done differently.
3. Measurement Errors: Sometimes, anomalies can be caused by mistakes or flaws in the tools used to collect data.
Fix: Set up strict quality control processes for the tools you use to collect data and think about using statistical methods to find and fix measurement errors.
4. Data Transformation Problems: If data transformation methods like normalization or scaling aren't done right, they can lead to anomalies.
Fix: Look over the steps for transforming data to make sure they are right for the data and don't add artifacts. If necessary, go over the steps for preparing data again.