Data is recorded measurements or observations collected, ideally, in a systematic way. It is an asset whose usefulness depends on quality, context, and origin—not an automatic source of truth. section 2.1 section 2.2
Data can take several practical forms:
- Structured data usually appears in tables, with variables in columns and observations in rows, ready for tools such as pandas or Excel. section 2.0
- Unstructured data includes documents, audio, and images; its many variables often make manual statistical analysis impractical. section 2.0
- A photograph, transaction record, temperature reading, or exam score is a data point that offers clues without capturing everything about reality. section 2.0 section 2.2
- Statistics turn large collections of observations into descriptive parameters that reveal patterns more quickly, while interpretation still requires attention to source and bias. section 1.2 section 2.2
The family photo test
A family photograph shows clothing, expressions, a room, and who is visible. It may provide surface-level clues, but it cannot reliably reveal the family’s complete life story: important events remain outside the frame. More data helps only when the additional observations are relevant and trustworthy. section 2.2
Use the figure to make the difference between recorded observations and the larger reality they represent visually concrete. section 2.1
