When working with statistics, aggregate data, and microdata, it is important to consider a number of factors:
- Geography - the country, region, city, neighborhood
- Time Period - current, historical, over time, etc.
- Population/Units of Analysis - age, sex, race, ancestry, educational attainment/households, individuals
- Variables - responses to questionnaire and how they are organized
- Context - what is the hypothesis being investigated
- Questionnaire - what questions were asked; shows what will and won't be available in the data
- Availability - Sometimes the data you require was not collected, or was not arranged in the way that works best for your project. You may need to use multiple types of data from different sources as a way around this.
- Source - When you find data online, make sure it is clear from where (and when)the information originated.
The UCLA Data Archive's Tutorials provides excellent information about working with social science data, citing data sources, how to read codebooks, etc.