To achieve partial control in ex post facto research, the researcher can
a. conduct a pilot study to determine a common cause.
b. match subjects on as many extraneous variables as possible.
c. randomly assign subjects to experimental and control groups.
d. b and c
Question 2
Identify the threats to internal validity illustrated in the example below. Some students left the experimental program because of a conflict with sports.
a. Instrumentation
b. Experimental mortality
c. Selection-maturation interaction
d. Statistical regression
e. Diffusion
Post–Main-Sequence Evolution of Low-Mass Stars
Margaret Sanger, birth control pioneer.
Heat Exchanger Block Diagram Feedback Control System
Control of blood glucose by pancreatic hormones.
Non-Hormonal Forms of Birth Control
A field study of guppy life history evolution.