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Data Analytics Flashcards

7 cards from real DIS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Data Analytics flashcards as text
  1. In a principal component analysis (PCA) of a multi-spectral imaging dataset, what does the first principal component represent?

    Answer: The direction of maximum variance in the feature space

    The first principal component is the linear combination of original variables that captures the greatest amount of variance in the dataset.

  2. A digital imaging quality system flags images with a noise level exceeding 3 standard deviations above the mean. This threshold corresponds to approximately what false positive rate?

    Answer: 0.3%

    In a normal distribution, 99.7% of values fall within ±3 standard deviations, leaving approximately 0.3% of values beyond this threshold as potential false positives.

  3. Which correlation coefficient is most appropriate for measuring the monotonic relationship between ranked image quality scores from two different evaluators?

    Answer: Spearman ρ (rho)

    Spearman's ρ measures the strength and direction of monotonic relationships using ranked data, making it appropriate for ordinal quality scores.

  4. A DIS certification candidate reviews an imaging system's confusion matrix: TP=90, FP=10, FN=5, TN=895. What is the precision of the defect detection system?

    Answer: 90%

    Precision = TP / (TP + FP) = 90 / (90 + 10) = 90/100 = 90%, representing the proportion of flagged items that are true defects.

  5. In imaging data pipelines, what is the primary benefit of using a data versioning system (such as DVC) alongside image datasets?

    Answer: It enables reproducible experiments by tracking dataset versions alongside model code

    Data versioning links specific dataset snapshots to the code and models trained on them, ensuring experiments can be exactly reproduced or audited later.

  6. When evaluating color consistency across a fleet of 50 identical scanners, an analyst finds the inter-device ΔE average is 3.8. What is the most appropriate next step?

    Answer: Perform device profiling and calibration to bring all units within acceptable tolerance

    A ΔE of 3.8 is clearly perceptible and indicates devices need individual profiling and calibration to achieve consistent, within-tolerance color output.

  7. A time-series analysis of daily scan output reveals a seasonal pattern with a 7-day cycle. Which analytical method is best suited to decompose and forecast this pattern?

    Answer: SARIMA (Seasonal ARIMA) modeling

    SARIMA explicitly models seasonal autocorrelation at defined periods, making it well-suited to decompose and forecast data with repeating weekly cycles.