Data Science FREE Data Science MCQ Question and Answers 3 — Questions and Answers
Question 1: What does the bias-variance tradeoff describe in machine learning?
- The balance between model simplicity and model complexity (Correct answer)
- The relationship between training speed and accuracy
- The tradeoff between data quantity and data quality
- The balance between supervised and unsupervised methods
Correct answer: The balance between model simplicity and model complexity
The bias-variance tradeoff describes how increasing model complexity reduces bias but increases variance, and finding the right balance minimizes total error.
Question 2: Which sampling method ensures that each subgroup of a population is proportionally represented in the sample?
- Stratified Sampling (Correct answer)
- Simple Random Sampling
- Convenience Sampling
- Cluster Sampling
Correct answer: Stratified Sampling
Stratified sampling divides the population into homogeneous subgroups and samples proportionally from each to ensure representative coverage.
Question 3: What is the main advantage of using ensemble methods like bagging and boosting?
- They reduce prediction error by combining multiple models (Correct answer)
- They eliminate the need for feature engineering
- They always run faster than single models
- They require less training data
Correct answer: They reduce prediction error by combining multiple models
Ensemble methods aggregate predictions from multiple models to reduce variance or bias, generally producing more accurate and robust results.
Question 4: In natural language processing, what does TF-IDF stand for?
- Term Frequency-Inverse Document Frequency (Correct answer)
- Text Format-Indexed Data File
- Token Filter-Internal Data Function
- Training Feature-Input Data Format
Correct answer: Term Frequency-Inverse Document Frequency
TF-IDF weights words by how frequently they appear in a document relative to how common they are across all documents in the corpus.
Question 5: Which type of data visualization is best suited for showing the distribution of a single continuous variable?
- Histogram (Correct answer)
- Scatter Plot
- Bar Chart
- Pie Chart
Correct answer: Histogram
Histograms display the frequency distribution of continuous data by grouping values into bins and showing their counts.
Question 6: What does the R-squared value indicate in a regression model?
- The proportion of variance in the dependent variable explained by the model (Correct answer)
- The correlation between two independent variables
- The probability that the model is correct
- The number of features used in the model
Correct answer: The proportion of variance in the dependent variable explained by the model
R-squared measures the percentage of variance in the target variable that is accounted for by the independent variables in the regression model.
Data Science FREE Data Science MCQ Question and Answers 3
What does the bias-variance tradeoff describe in machine learning?