CompTIA Data+ (DA0-002) — the full course

Every lesson and every lab is free to read, mapped one-to-one to CompTIA’s published exam objectives. The paid tier adds the 510-question exam simulator; nothing is taken away from the free course to make room for it.

51written lessons

74hands-on labs

53hours of lab work

510practice questions

Start with lesson 1 — A data workbench you can break, and the practice data sets Exam simulator

Jump to a domain: 1. Data concepts and environments · 2. Data acquisition and preparation · 3. Data analysis · 4. Visualization and reporting · 5. Data governance

What the exam weighs

Domain	Share of the exam	Lessons here
1. Data concepts and environments	20%	10
2. Data acquisition and preparation	22%	11
3. Data analysis	24%	12
4. Visualization and reporting	20%	10
5. Data governance	14%	7

The curriculum

1. Data concepts and environments 20% of the exam

01 Databases: relational, NoSQL and the data warehouse objective 1.1 part single
- Reshape the shop database into a star schema applied · 60 min
- Map the keys and relationships in the practice database short · 35 min
02 Data types, data structures and file formats objective 1.1 part single
- Catch the type damage in a dirty file and flatten a nested one short · 40 min
03 Data sources: databases, APIs and website data objective 1.2 part single
- Collect files over HTTP and prove they arrived intact applied · 45 min
- Page through a source until it runs out, and prove you got everything short · 35 min
04 Data sources: files, logs and repositories objective 1.2 part single
- Parse a web server log into rows and count its failures short · 40 min
05 Cloud, on-premises and where the data lives objective 1.3 part single
- Move the computation to the data, and measure what it saves short · 30 min
06 Storage and containerization for data work objective 1.3 part single
- Compress a data set and measure what the layout changes applied · 40 min
- Partition a table by month and read only what a query needs short · 40 min
07 Coding environments: SQL, Python, R and notebooks objective 1.4 part single
- Answer one question in SQL and in Python, and prove they agree applied · 50 min
- Put an analysis under version control and watch it change short · 35 min
08 BI software, spreadsheets and analysis platforms objective 1.4 part single
- Define a measure once and make every report use it capstone · 75 min
- Find the total row that doubles a spreadsheet sum short · 30 min
09 AI models and machine learning, for analysts objective 1.5 part single
- Beat a do-nothing model, and see why accuracy alone misleads short · 35 min
10 Natural language processing and robotic process automation objective 1.5 part single
- Score comment sentiment and check it against the numbers applied · 50 min
- Turn free-text comments into word counts short · 35 min

2. Data acquisition and preparation 22% of the exam

01 Querying with SQL: SELECT, WHERE and ORDER BY objective 2.1 part single
- Predict a query's row count, then run it short · 35 min
02 Joins and combining data sets objective 2.1 part single
- Deduplicate a key before joining, and prove the join is clean applied · 50 min
- Count the rows a join adds and the rows it loses short · 40 min
03 Aggregation, grouping and subqueries objective 2.1 part single
- Group, filter groups, and average at the right level short · 40 min
04 Data integration: ETL, ELT and pipelines objective 2.1 part single
- Load incrementally with a watermark, and run it twice safely short · 45 min
05 Profiling a new data set before trusting it objective 2.2 part single
- Profile the raw customer file before trusting it short · 40 min
06 Missing values, duplicates and redundancy objective 2.2 part single
- Merge the duplicates with a written survivorship rule applied · 50 min
- Find the missing values and the near duplicates short · 35 min
07 Finding and handling outliers objective 2.2 part single
- Flag outliers two ways and catch the error one of them misses short · 40 min
08 Cleansing and standardising data objective 2.3 part single
- Clean regions and names with a mapping table, and count every change short · 40 min
09 Merging, appending and reshaping data objective 2.3 part single
- Pivot to wide, unpivot to long, and check the total survives short · 40 min
10 Parsing dates, strings and structured fields objective 2.3 part single
- Rebuild the clean customer file from the dirty one applied · 60 min
- Parse mixed date formats, and measure what guessing would cost short · 40 min
11 Formatting, derived fields and preparing features objective 2.3 part single
- From raw files to an analysis-ready table capstone · 90 min
- Derive order values, band them, and catch the rounding trap short · 40 min

3. Data analysis 24% of the exam

01 Descriptive statistics: centre and spread objective 3.2 part single
- Summarise a skewed column, and choose which summary to report short · 35 min
02 Distributions and the shape of data objective 3.2 part single
- Tabulate a distribution and test the empirical rule on real readings short · 35 min
03 Sampling, bias and confidence intervals objective 3.2 part single
- Draw a sample, measure its error, and put an interval on a mean short · 40 min
04 Hypothesis testing and statistical significance objective 3.2 part single
- Test whether discounts change order size applied · 50 min
- Run the same A/B test at two sample sizes short · 35 min
05 Correlation and regression objective 3.2 part single
- Run a small analysis from question to caveated finding capstone · 90 min
- Measure a relationship and fit a line to it short · 35 min
06 Trends, time series and the types of analysis objective 3.2 part single
- Separate a month's rise from the length of the month short · 35 min
07 Knowing the audience for an analysis objective 3.1 part single
- Write one finding for two audiences short · 30 min
08 Presenting findings with their limits objective 3.1 part single
- Present a finding with its range and its limits short · 35 min
09 Choosing the method for the question and the audience objective 3.1 part single
- Define a KPI precisely and calculate it applied · 45 min
- Classify questions before choosing methods short · 25 min
10 When the numbers do not agree: reconciling results objective 3.3 part single
- Reconcile three revenue totals with a bridge short · 40 min
11 Common analysis errors, from double counting to Simpson's paradox objective 3.3 part single
- Reproduce Simpson's paradox and explain it applied · 40 min
- Catch an average of averages short · 30 min
12 Tools and resources for fixing an analysis objective 3.3 part single
- Find the step where the numbers first go wrong short · 40 min

4. Visualization and reporting 20% of the exam

01 Choosing the right chart for the question objective 4.1 part single
- Answer a comparison question with a bar chart you can check short · 40 min
02 Maps and geographic data objective 4.1 part single
- Normalise by customers before you map a region short · 35 min
03 Design elements: colour, labels and accessibility objective 4.1 part single
- Test a palette's contrast before it ships short · 35 min
04 Misleading visuals and how to spot them objective 4.1 part single
- Rebuild a misleading chart honestly applied · 50 min
- Measure the lie factor of a truncated axis short · 30 min
05 Dashboards against reports objective 4.2 part single
- Build a one-page static report from the data applied · 60 min
- Specify a dashboard before anyone builds it short · 30 min
06 Delivering reports: scheduling, distribution and self-service objective 4.2 part single
- Split a report so each manager sees only their region short · 35 min
07 Filters, drill-down and interactivity objective 4.2 part single
- Find the filter nobody noticed, then drill down short · 35 min
08 Validating a report against its source objective 4.3 part single
- Carry control totals through a pipeline and trace one record applied · 50 min
- Recompute the headline numbers by a second route short · 35 min
09 Refresh failures and stale data objective 4.3 part single
- Catch stale data from its own timestamps short · 35 min
10 Review and quality control before publishing objective 4.3 part single
- Review a report before it is published capstone · 90 min
- Test a report's filters at their edges short · 40 min

5. Data governance 14% of the exam

01 Documentation: data dictionaries and metadata objective 5.1 part single
- Generate a data dictionary, and let it catch drift short · 40 min
02 Versioning and data lineage objective 5.1 part single
- Record lineage and run an impact analysis applied · 50 min
- Version a data set by its hash short · 35 min
03 Regulations and data classification objective 5.2 part single
- Classify every column before you share a file short · 30 min
04 Retention and audits objective 5.2 part single
- Apply a retention rule, respect a legal hold, and prove the deletion applied · 50 min
- Build an audit trail that shows when it was edited short · 40 min
05 Access control and encryption for data objective 5.3 part single
- Give the West manager a view, not the table short · 35 min
06 Masking, anonymisation and pseudonymisation objective 5.3 part single
- Pseudonymise customers with a keyed hash, and see who can reverse it applied · 50 min
- Mask emails for display, and suppress small groups short · 35 min
07 Data quality: profiling, monitoring and testing objective 5.4 part single
- Write data quality tests that can stop a pipeline applied · 50 min
- Monitor quality day by day and log each issue to its source capstone · 90 min
- Score four quality dimensions on the raw customer file short · 35 min

Supplementary not examined — background reading

01 A data workbench you can break, and the practice data sets part single
- Build the workbench and prove the data is what it claims to be short · 30 min

The exam simulator

510 questions, every one mapped to an objective and to the lesson that teaches it. Timed full-length papers drawn to the real domain split, retakes weighted to your weak areas, and a readiness report from your own results.

Open the simulator See the paid tier

This is an independent study companion for CompTIA Data+ DA0-002 and is not produced by or endorsed by CompTIA.