Data Analytics, Data Management and the Data Life Cycle
Core concepts
Data analytics is the process of turning raw data into information that supports decisions. Distinguish data (raw recorded values), information (data given context and meaning) and knowledge (patterns understood well enough to act on). Data management covers how data is collected, stored, secured, shared, archived and destroyed. Candidates must know the data life cycle: acquisition, preparation/cleaning, storage and management, analysis, visualisation and communication, and disposal or archiving.
Data integrity and validation
Data integrity means data is accurate, complete, consistent and current. Validation checks data at the point of entry (for example a range check on a test score, a type check on a date field, a presence check for a required field, or a check digit on an ID). Verification confirms data matches its source (double entry, proofreading against a form). A key trap: validation cannot guarantee accuracy - a valid value can still be wrong. For example, a range check of 0–100 accepts a score of 85 entered when the true score was 58. Validation reduces errors but does not eliminate them; only verification against the original source catches such mistakes.
Traps in exam questions
Questions often ask which life-cycle stage is occurring in a scenario. Cleaning duplicate customer records is preparation, not acquisition. Setting file permissions is management, not analysis. Another trap is confusing integrity with security: encryption protects confidentiality but does not make data correct. Also remember that poor-quality input data produces poor-quality output regardless of sophisticated analysis - the "garbage in, garbage out" principle.
Rule of thumb
When asked to improve data quality, name the specific problem (duplicate, missing, inconsistent format, outlier, invalid value) and then name the specific technique that fixes it. A general answer such as "clean the data" earns little credit; "remove duplicate customer IDs by matching on email and retaining the most recent record" demonstrates understanding.