What aspects should be considered to improve the readability of a graph?
- All of the mentioned
- The amount of data displayed
- The color scheme
- The scale and labels
Improving the readability of a graph involves considering several aspects, including the color scheme (which should be clear and not misleading), the scale and labels (which should be appropriate and informative), and the amount of data displayed (too much data can overwhelm the audience and obscure the main message).
Standardization or z-score normalization is a scaling technique where the values are centered around the _____ with a unit _____.
- mean; standard deviation
- mean; variance
- median; interquartile range
- mode; range
Standardization or z-score normalization is a scaling technique where the values are centered around the mean with a unit standard deviation. This technique subtracts the mean from each observation and then divides by the standard deviation, effectively scaling the data to have a mean of 0 and a standard deviation of 1.
Which plot is ideal for visualizing the full distribution of a variable including its probability density, quartiles, and outliers?
- Box plot
- Line plot
- Scatter plot
- Violin plot
Violin plots are ideal for visualizing the full distribution of a variable including its probability density, quartiles, and outliers. These plots combine a box plot and a density plot, providing a rich, dense summary of the data.
Why is readability important in data visualization?
- To demonstrate the designer's skills
- To ensure the graph looks good
- To help the audience understand and interpret the data correctly
- To make the graph appealing to the audience
Readability is crucial in data visualization because it directly impacts the audience's ability to understand and interpret the data correctly. A readable graph communicates the data's message effectively, allows the audience to draw accurate conclusions, and makes the data accessible to a broader audience.
If a machine learning model uses distance-based methods, we need to apply _____ to bring all features to the same level of magnitudes.
- Binning
- Data Encoding
- Data Integration
- Data Scaling
If a machine learning model uses distance-based methods, we need to apply Data Scaling to bring all features to the same level of magnitudes. This is because distance-based methods are sensitive to the scale of the features.
EDA techniques can help detect ________ in a dataset.
- Data leakage
- Multicollinearity
- Overfitting
- Underfitting
EDA techniques can help detect multicollinearity in a dataset. By examining correlation matrices or scatter plots, we can get a sense of whether predictor variables are correlated with each other, which might indicate multicollinearity. This is an important consideration as multicollinearity can affect the interpretability of some models and can lead to unstable estimates of regression coefficients.
Consider you are dealing with a dataset with zero skewness but high kurtosis. How would this shape the data distribution and affect your analysis?
- The data distribution would be negatively skewed with a wider spread.
- The data distribution would be perfectly symmetrical with a narrower spread and potential outliers.
- The data distribution would be perfectly symmetrical with a wider spread.
- The data distribution would be positively skewed with a narrower spread.
Zero skewness means the distribution is symmetrical, and high kurtosis means the distribution is leptokurtic with a sharp peak and fatter tails. Therefore, the data distribution will be symmetrical but with a potential for outliers. This may affect the results of statistical tests or models that assume normality, as extreme values could have a disproportionate effect on the results.
You have a large dataset where removing the outliers would lead to loss of significant data. What method would you recommend for outlier handling?
- Binning
- Removal
- Transformation
- nan
If the dataset is large and removing outliers would lead to a significant loss of data, binning could be a suitable method. In binning, the outliers are not removed but rather they are replaced with summary statistics like mean, median, etc.
When would you choose a histogram over a kernel density plot for univariate data visualization?
- When data is categorical
- When data is continuous
- When data is discrete
- When data is skewed
A Histogram is preferred over a kernel density plot for discrete data. While kernel density plots can give a smoother representation of data, they are more suitable for continuous data. A histogram's bar-like representation suits the discrete nature of the data.
The removal of outliers can lead to a reduction in the ________ of the data set.
- Mean
- Median
- Mode
- Variability
The removal of outliers often leads to a reduction in the variability (or variance) of the dataset as outliers are extreme values that increase variability.
When features in a dataset are highly correlated, they might suffer from a problem known as ________, which can negatively impact the machine learning model.
- Bias
- Multicollinearity
- Overfitting
- Underfitting
When features in a dataset are highly correlated, they might suffer from a problem known as multicollinearity, which can negatively impact the machine learning model. Multicollinearity can affect the stability and interpretability of the model, and may cause certain algorithms to perform poorly.
The method of transforming data to handle outliers often involves applying a ________ to the data.
- Box-Cox transformation
- Inverse transformation
- Logarithmic transformation
- Square root transformation
The logarithmic transformation is a common method used in data transformation to handle outliers. It helps in pulling in high values, which reduces skewness.