Accessing Environmental Data Flashcards
Data are raw measurements, such as the concentration of a contaminant. T or F?
True; data are raw measurements of the concentration, distribution, and env. fate of a given agent or contaminate.
TRI includes information on agent-specific characteristics, including toxicity in humans and animals. T or F?
False; the TRI database is a compilation on the release of toxic substances by manufacturing facilities
What agency is properly paired with its mission or areas of responsibility?
ATSDR/Prevent or mitigate human health problems and diminished quality of life resulting from exposure to hazardous substances
What is the least likely pathway of exposure to the surrounding community emanating from a hazardous waste site?
Airborne contaminants entering the lungs
Accuracy + Precision = ?
Validity
Accuracy vs Precision? Which one would you rather have first to improve data?*
Accuracy - how close to the true value
Precision* - how reproduceable are the results, or how tight is the pattern
How is a body of sampling data characterized?
Descriptive Statistics; generally of two types:
- Measures of central tendency: Mean, Median, Mode
- Measures of dispersion: Range, Variance, Standard Deviation
Why can we generally use model distributions in analyzing data?
Central Limit Theorem; allows the use of “statistics” to test for “differences” in datasets from populations of interest
What is the Central Limit Theorem?
States that no matter what the shape of the parent population distribution, the sampling distribution of a statistic (say a “sampling mean”) will have a normal distribution…when certain conditions are met
Differences between descriptive and inferential statistics?
Descriptive: develop “characteristic” attributes for the data
Inferential: Hypothesis testing using these attributes.
