Data Validation and Classification Quiz
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Questions and Answers

What is the purpose of identifying outliers in a dataset?

  • To improve the accuracy of statistical methods (correct)
  • To introduce errors in the data
  • To decrease the stability of neural networks
  • To maintain inconsistencies in the data

In the context of data analysis, what is the role of normalization?

  • To introduce errors into the data
  • To scale and transform data for better analysis (correct)
  • To maintain extreme values in the dataset
  • To prevent the identification of outliers

Which statistical methods benefit from normalized data according to the text?

  • Neural Networks and k-Means (correct)
  • Methods that rely on outliers
  • Methods that are insensitive to data distribution
  • Methods that avoid data preprocessing

What is the significance of maintaining consistency in class labels for data from different origins?

<p>To avoid errors in data entry (A)</p> Signup and view all the answers

Why might a value like 192.5 pounds be considered an outlier in a dataset focused on whole-numbered weight values?

<p>It represents an error in data labeling (C)</p> Signup and view all the answers

How does a histogram aid in identifying outliers in a dataset?

<p>By highlighting extreme values in the dataset (A)</p> Signup and view all the answers

What is the downside of deleting records containing missing values?

<p>Creates a biased subset (C)</p> Signup and view all the answers

Which method of handling missing data involves replacing missing numeric values with 0.0 and missing categorical values with 'Missing'?

<p>Replacing with User-defined Constant (C)</p> Signup and view all the answers

Why is replacing missing values with random values considered superior to mean substitution?

<p>Measures of location and spread are closer to the original (C)</p> Signup and view all the answers

When replacing missing values with random values, what is the potential risk regarding the resulting records?

<p>They might introduce outliers (C)</p> Signup and view all the answers

In handling missing data, why is it important to consult domain experts regarding the replacement approach?

<p>To evaluate benefits and drawbacks (A)</p> Signup and view all the answers

Which method involves replacing missing values based on the mode for categorical fields and the mean for numeric fields?

<p>Replacing with Mode or Mean (D)</p> Signup and view all the answers

What is a common characteristic of the two possible outliers identified in the scatter plot of mpg against weightlbs?

<p>They both have extremely high gas mileage. (B)</p> Signup and view all the answers

What is a common measure of center used for datasets with skewed distributions?

<p>Median (A)</p> Signup and view all the answers

What is a measure of spread that includes the range, standard deviation, mean absolute deviation, and interquartile range?

<p>Standard Deviation (D)</p> Signup and view all the answers

In data transformation, why is it important to normalize numeric field values?

<p>To ensure all variables have the same range of effect on results (B)</p> Signup and view all the answers

Which normalization technique involves scaling the field value based on the range between the minimum and maximum values?

<p>Min-max normalization (C)</p> Signup and view all the answers

In transformation to achieve normality, what analysis tool is used to check if the distribution is normal?

<p>Normal probability plot (A)</p> Signup and view all the answers

Why is it suggested that ID fields should be filtered out from downstream data mining algorithms?

<p>ID fields do not add value to the analysis. (C)</p> Signup and view all the answers

What is a common issue with variables containing a high percentage of missing values?

<p>They may bias imputation strategies. (A)</p> Signup and view all the answers

'Double-counting' can occur when including what type of variables in analysis?

<p>'Correlated' variables (B)</p> Signup and view all the answers

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