By contacting social workers registered through a provincial association, a researcher wants to know

By contacting social workers registered through a provincial association, a researcher wants to know if the social workers who have worked longer in one position (measured by placing the workers into three groups – new (less than 5 years employed), middle (6-10 years), and long (over 10 years) are more satisfied (measured as not satisfied, satisfied, and very satisfied) with their employment.
a) Would the researcher be able to obtain a sampling frame?
b) What procedures would the researcher have to follow to obtain a probability sample?
c) Name the two main variables that would be tested in this study and the level of measurement of these variables.
d) Name the statistical tests that would be used to test this relationship.