A local hospital is piloting a program to see if they can cure patients with a fear of spiders using therapy
sessions. Typically, 9 or 10 therapy sessions are
needed before the improvement is noticed. An
experimenter wants to test if using a new drug, D-
anthamine, would help patients cure their fear of
spiders in fewer therapy sessions.
Each of the 27 people involved in the study received a
pill before each of two therapy sessions. 17 of the 27
people were randomly assigned the D-anthamine pill
while the remaining 10 received a placebo. After the
two therapy sessions, none of the patients received
additional pills or therapy. Three months after the
administration of the pills and the two therapy sessions,
each of the 27 people were evaluated to see if their
fear of spiders had improved.
a. Was this an experiment or an observational
study? Provide justification for your choice.