Podcast
Questions and Answers
What does 'incomplete' data refer to?
What does 'incomplete' data refer to?
- Data containing errors and outliers
- Data with missing attribute values or lacking certain attributes (correct)
- Data with intentional disguises
- Data with discrepancies in codes or names
Which is an example of 'noisy' data?
Which is an example of 'noisy' data?
- Occupation=“ ” (missing data)
- Was rating “1, 2, 3”, now rating “A, B, C”
- Age=“42”, Birthday=“03/07/2010”
- Salary=“−10” (an error) (correct)
In data cleaning, what is one reason for missing data?
In data cleaning, what is one reason for missing data?
- Intentional disguises
- Discrepancies in codes or names
- Equipment malfunction (correct)
- Duplicate records
How is missing data usually handled when the class label is missing?
How is missing data usually handled when the class label is missing?
What is a suggested method for filling in missing values automatically?
What is a suggested method for filling in missing values automatically?
Why might certain data not be considered important at the time of entry?
Why might certain data not be considered important at the time of entry?
What does the null rule specify?
What does the null rule specify?
What is ETL in the context of data migration and integration?
What is ETL in the context of data migration and integration?
Which major task is NOT part of Data Preprocessing?
Which major task is NOT part of Data Preprocessing?
What is the purpose of data scrubbing in data cleaning?
What is the purpose of data scrubbing in data cleaning?
What is the primary goal of data integration?
What is the primary goal of data integration?
What does entity identification problem refer to in data integration?
What does entity identification problem refer to in data integration?
What is a possible reason for attribute values from different sources to be different?
What is a possible reason for attribute values from different sources to be different?
In data integration, what is one way to detect redundant attributes?
In data integration, what is one way to detect redundant attributes?
What does a larger Χ2 value indicate in correlation analysis of nominal data?
What does a larger Χ2 value indicate in correlation analysis of nominal data?
In the Chi-Square calculation example provided, how is the Chi-Square value calculated?
In the Chi-Square calculation example provided, how is the Chi-Square value calculated?
What does the Correlation Coefficient measure in correlation analysis of numeric data?
What does the Correlation Coefficient measure in correlation analysis of numeric data?
What does it mean when two attributes have a high Correlation Coefficient value?
What does it mean when two attributes have a high Correlation Coefficient value?
What is the purpose of splitting in the context of unsupervised data preprocessing?
What is the purpose of splitting in the context of unsupervised data preprocessing?
What is a common technique mentioned for data smoothing in the text?
What is a common technique mentioned for data smoothing in the text?
What is the purpose of concept hierarchy generation in a data warehouse?
What is the purpose of concept hierarchy generation in a data warehouse?
How are concept hierarchies usually formed according to the text?
How are concept hierarchies usually formed according to the text?
Which task is NOT a part of data preprocessing based on the text?
Which task is NOT a part of data preprocessing based on the text?
What does data transformation and discretization involve according to the text?
What does data transformation and discretization involve according to the text?
What does a positive covariance between two variables indicate?
What does a positive covariance between two variables indicate?
What does a covariance of 0 between two variables suggest?
What does a covariance of 0 between two variables suggest?
How does negative covariance impact the relationship between two variables?
How does negative covariance impact the relationship between two variables?
When does a covariance of 0 imply independence between two variables?
When does a covariance of 0 imply independence between two variables?
In the context of stock prices, what does it mean when two stocks have a positive covariance?
In the context of stock prices, what does it mean when two stocks have a positive covariance?
What is the relationship between correlation coefficient and covariance?
What is the relationship between correlation coefficient and covariance?
