What is a common technique to prevent overfitting in linear regression models?
- Increasing the model complexity
- Reducing the number of features
- Regularization
- Using a smaller training dataset
Regularization is a common technique used to prevent overfitting in linear regression models. It adds a penalty term to the linear regression's cost function to discourage overly complex models. Regularization techniques include L1 (Lasso) and L2 (Ridge) regularization.
In a skewed distribution, which measure of central tendency is most resistant to the effects of outliers?
- Mean
- Median
- Mode
- Geometric Mean
The median is the most resistant measure of central tendency in a skewed distribution. It is less affected by extreme values or outliers since it represents the middle value when the data is arranged in order. The mean, mode, and geometric mean can be heavily influenced by outliers, causing them to be less representative of the data's central location.
A common architecture for real-time data processing involves using ________ to ingest and process streaming data.
- Hadoop
- Spark
- Batch Processing
- Data Lakes
In real-time data processing, Apache Spark is commonly used to ingest and process streaming data. Spark provides the capabilities to handle streaming data in real time, making it a popular choice for such applications.
An AI startup with limited computational resources is building an image classifier. They don't have the capability to train a deep neural network from scratch. What approach can they use to leverage the capabilities of deep learning without the extensive training time?
- Transfer learning
- Reinforcement learning
- Genetic algorithms
- Random forest classifier
Transfer learning allows the startup to use pre-trained deep neural networks (e.g., a pre-trained CNN) as a starting point. This approach significantly reduces training time and computational resources, while still benefiting from the capabilities of deep learning.
Which metric provides a single score that balances the trade-off between precision and recall?
- F1 Score
- Accuracy
- ROC AUC
- Log Loss
The F1 Score is a metric that balances the trade-off between precision and recall. It is especially useful when dealing with imbalanced datasets or when you want to find a balance between correctly identifying positive cases (precision) and capturing all positive cases (recall). The F1 Score is the harmonic mean of precision and recall. It is a suitable choice for evaluating models when both precision and recall are essential.
In recurrent neural networks (RNNs), which variant is designed specifically to handle long-term dependencies by maintaining a cell state?
- LSTM (Long Short-Term Memory)
- GRU (Gated Recurrent Unit)
- SRU (Simple Recurrent Unit)
- ESN (Echo State Network)
Long Short-Term Memory (LSTM) is a variant of RNN designed to handle long-term dependencies by maintaining a cell state that can capture information over long sequences. LSTM's ability to store and retrieve information over extended time steps makes it well-suited for tasks involving long-term dependencies in data sequences.
Which method for handling missing data involves using algorithms like k-NN to find similar records to impute the missing value?
- Mean imputation
- Median imputation
- k-NN imputation
- Mode imputation
k-NN imputation is a technique that uses the similarity of data points to impute missing values. It finds records with similar characteristics to the one with missing data and replaces the missing value with the imputed value from its nearest neighbors. Other options are simpler imputation methods.
In the context of binary classification, which metric calculates the ratio of true positives to the sum of true positives and false negatives?
- Precision-Recall Curve
- F1 Score
- True Positive Rate (Sensitivity)
- Specificity
The True Positive Rate, also known as Sensitivity or Recall, calculates the ratio of true positives to the sum of true positives and false negatives. It measures the model's ability to correctly identify positive cases. It is an important metric in binary classification evaluation.
What is the most common measure of central tendency, which calculates the average value of a dataset?
- Median
- Mode
- Mean
- Standard Deviation
The mean, also known as the average, is a common measure of central tendency. It's calculated by adding up all the values in the dataset and then dividing by the number of data points. The mean provides a sense of the "typical" value in the dataset.
Which step in the Data Science Life Cycle is concerned with cleaning the data and handling missing values?
- Data Exploration
- Data Collection
- Data Preprocessing
- Data Visualization
Data Preprocessing is the step in the Data Science Life Cycle that involves cleaning the data, handling missing values, and preparing it for analysis. This step is crucial for ensuring the quality and reliability of the data used in subsequent analysis.
In the context of outlier detection, what is the commonly used plot to visually detect outliers in a single variable?
- Box Plot
- Scatter Plot
- Histogram
- Line Chart
A Box Plot is a commonly used visualization for detecting outliers in a single variable. It displays the distribution of data and identifies potential outliers based on the interquartile range (IQR). Data points outside the whiskers of the box plot are often considered outliers. Box plots are useful for identifying data anomalies.
In time-series data, creating lag features involves using previous time steps as new _______.
- Predictors
- Observations
- Predictions
- Variables
In time-series analysis, creating lag features means using previous time steps (observations) as new data points. This allows you to incorporate historical information into your model, which can be valuable for forecasting future values in time series data.