Mixed Deck — All Data and Analytics Topics Flashcards
100 cards from real Data and Analytics practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All Data and Analytics Topics flashcards as text
What does an ROC curve illustrate in model evaluation?
Answer: The tradeoff between true positive rate and false positive rate at various thresholds
An ROC curve plots the true positive rate against the false positive rate across different classification thresholds, showing a model's discriminative ability.
Which visualization tool is most commonly used for business intelligence dashboards in the US?
Answer: Tableau
Tableau is the leading BI dashboard tool in the US enterprise market, known for its drag-and-drop interface and interactive dashboards.
What is data deduplication?
Answer: The process of identifying and removing duplicate records from datasets
Data deduplication identifies and eliminates duplicate records in datasets to ensure each entity appears only once, improving data quality.
What does 'data mesh' refer to in modern data architecture?
Answer: A decentralized approach where domain teams own and manage their own data as products
Data mesh is a decentralized architectural approach that treats data as a product, with domain-oriented teams owning their own data pipelines.
What is Delta Lake?
Answer: An open-source storage layer that brings ACID transactions to data lakes
Delta Lake is an open-source storage layer that adds ACID transaction support, schema enforcement, and time travel capabilities to data lakes.
Which AWS service is a fully managed data warehouse solution?
Answer: Amazon Redshift
Amazon Redshift is AWS's fully managed, petabyte-scale cloud data warehouse optimized for analytics workloads.
What does a NULL value represent in a database?
Answer: An unknown or missing value
NULL represents the absence of a value or an unknown value in a database field.
What is Snowflake's multi-cluster, shared data architecture?
Answer: Separate storage and compute layers allowing multiple independent query engines
Snowflake separates storage from compute, allowing multiple virtual warehouses to independently access the same data without contention.
Which algorithm builds an ensemble of decision trees using random subsets of features and training samples?
Answer: Random Forest
Random Forest creates multiple decision trees using random feature subsets and bootstrap samples, then aggregates their predictions to improve accuracy and reduce overfitting.
Which SQL JOIN returns only rows where there is a match in both tables?
Answer: INNER JOIN
INNER JOIN returns only the rows that have matching values in both joined tables.
Which chart type is best for showing the distribution of a single continuous variable?
Answer: Histogram
A histogram displays the frequency distribution of continuous data by grouping values into bins.
Which color scale is recommended for sequential data with a meaningful zero point?
Answer: Sequential single-hue scale
A sequential single-hue scale uses varying lightness of one color to represent ordered data, making magnitude differences clear.
What is the purpose of a choropleth map?
Answer: Using color intensity to represent data values across geographic regions
A choropleth map shades geographic regions with colors proportional to a data variable, enabling geographic comparisons.
What does the p-value represent in hypothesis testing?
Answer: The probability of observing results as extreme as the data if the null hypothesis is true
The p-value is the probability of obtaining results at least as extreme as observed, assuming the null hypothesis is true.
What is a foreign key in a relational database?
Answer: A column that references the primary key of another table
A foreign key establishes a referential link between a column in one table and the primary key of another table.
Which statistical test compares means across more than two independent groups?
Answer: ANOVA
ANOVA (Analysis of Variance) tests whether the means of three or more independent groups are significantly different.
Which approach is used to handle missing values in a dataset by replacing them with the mean, median, or mode?
Answer: Imputation
Imputation fills in missing values with a statistical estimate (mean, median, or mode) or a model-based prediction to preserve data completeness for training.
What are the 3 Vs traditionally used to define Big Data?
Answer: Velocity, Volume, Variety
The original three defining characteristics of Big Data are Volume (size), Velocity (speed of generation), and Variety (different data types).
What chart type is most appropriate for comparing parts of a whole across multiple categories?
Answer: Stacked bar chart
A stacked bar chart shows how each category's total is composed of subcategories, enabling part-to-whole comparisons.
What is the purpose of data profiling?
Answer: Analyzing datasets to understand structure, content, quality, and relationships
Data profiling examines dataset characteristics including structure, content, quality, completeness, and statistical properties to understand the data before use.