Compared with $\_\_\_\_\_\_\_\_\_\_$ data, two disadvantages of $\_\_\_\_\_\_\_\_\_\_$ data are that it is usually far more time consuming and more expensive to collect.

Question $16$ options:

a$)$

secondary; primary

b$)$

primary; secondary

c$)$

differential; observational

d$)$

sample; population

e$)$

open ended; closed