What are the methods of data preprocessing?

The main idea of data cleaning (data cleaning) is to fill in missing values, smooth noisy data, smooth or remove outliers, and resolve data inconsistencies to? cleaning? data. If users perceive the data as dirty, they are less likely to trust the results of mining based on that data, i.e., the output is unreliable.

2. Data Integration

Data analysis tasks mostly involve data integration. Data integration combines data from multiple data sources into, and stores them in, a consistent data store, such as a data warehouse. These sources may include multiple databases, data parties, or general files.

3. Data Statute

Data reduction techniques can be used to obtain a reduced representation of a data set that is much smaller, but still close enough to maintain the integrity of the original data. In this way, mining on the normalized dataset will be more efficient and produce the same (or nearly the same) analytical results.

4, data transformation

Data transformation involves normalizing, discretizing, and sparsifying the data to achieve the purpose of mining.