Basics of statistics Flashcards
Disadvantages of running a census?
- difficult to identify, locate, and survey all units
- higher cost of running
- population of interest may change
How is the stratified random sample obtained?
by dividing the population into mutually exclusive sets (or strata), an then drawing simple random sample from each stratum.
The most commonly used sampling plans are:
- simple random sampling
- stratified random sampling
- cluster sampling
What are numerical data types?
values are numbers, all calculations are valid
What are parameters?
a descriptive measure of a population
What are nominal data types?
Values are the arbitrary numbers that represent categories.
Only calculations, such as proportions, based on the frequencies of occurrence are valid.
What is a statistic?
A descriptive measure of a sample
What is ordinal data?
values must represent the ranked order of the data.
calculations based on an ordering process are valid.
What is population?
the group of all items (data) of interest. Frequently large and sometimes infinite.
What is sample?
a set of data drawn from a full population of interest.
What’s the difference between observational and experimental study?
Observational data is observed and recorded without controlling any factor that might influence their values. Experimental studies seek to control factors.
