Note 1
Data
Are measurements that are disorganized
Discrete Variables
Data which is obtained by counting
When applying this method, each chosen member is assigned a unique number and a random number generator is used to select individuals to be observed, or drawing names, ect.
Simple Random Sampling
When applying this method, the members of the entire population are invited to respond to a survey and no effort is made for a random sampling
Voluntary-Response Sampling
The sampling does not accurately represent the population
Sampling Bias
Information
Data that is organized
Continuous Variables
Data which is obtained by counting
When applying this method, usually the entire population is put into a specific order such as alphabetically by last name
Systematic Random Sampling
When applying this method, the members of a population are selected simply because they are easily accessible
Convenience Sampling
Method of data collection, such as questionnaires, are not returned and so results are influenced
Non-Response Bias
Random Variables
Variables whose data is determined by chance
A type of continuous variable data which classifies data into non-overlapping categories with no order or ranking
Nominal Measurement
When applying this method, a combination of sampling techniques in several stages is used to sample the population
Multi-Stage Random Sampling
Interval Size
To find the interval size, take the number of individuals in a population, ex. 100, and divide by the number of individual being sampled, ex. 20, to find the interval size, ex. each interval would contain 5 people
Strata (divisions) from the sampling frame are not equally represented
Household Bias
Qualitative Variables
Variables that can be placed into distinct categories, according to some characteristic
A type of continuous variable data that classifies data into categories that can be ordered/ranked but there are no precise difference between the ranks
Ordinal Measurement
When applying this method, the entire population is put into different categories, called strata
Stratified Random Sampling
Population
A group of objects that is the focus of a study
Factors in the sampling method influence the data obtained. This is a type of cognitive bias which can affect the results
Response Bias
Quantitative Variable
Variables that are numerical and can be used in mathematical calculations, and can be further classified by the type of number they are
A type of continuous data that classifies data into categories that can be ranked and therefore there are precise difference between the ranks
Interval Measurement
When applying this method, a convenient way of organizing the population into different groups is necessary
Cluster Random Sampling
Sample
A selection of objects taken from the popualtion
Primary Data
Data that is collected by the actual researcher