An experimental design
a. is one in which the investigator has direct control over at least one independent variable.
b. is less capable of providing evidence of causal relationships than is an exploratory design.
c. is less internally valid than a descriptive study.
d. should be used only in realistic situations.
e. is best suited for longitudinal analysis.
Question 2
Typically, __________ experiments have greater internal validity, and __________
experiments have greater external validity.
a. lab; field
b. field; lab
c. field; field
d. lab; lab
e. The internal and external validities are usually the same for both types of experiments.
endocrine feedback control
Negative feedback control of the female reproductive hormones
Quality Control Microbiology
Apply direct pressure to points along the shoulders. Stand to one side and use your forearm to apply ...
Control of Respiration
Control of flower formation, as revealed by mutations in Arabidopsis thaliana.