According to the logical positivists,

a. unobservable theoretical entities can be studied as long as they are tied to observable events
b. operational definitions are inadequate to capture the range of meanings that can be associated with such terms as hunger
c. unobservable theoretical entities have no place in science behaviorism can never be
d. an adequate approach to science because it cannot account for unobservable theoretical entities

Awaiver of the requirement for documentation of informed consent may be granted when: the investigator has no convenient place to store signed consent forms separate from the research datathe only record linking the subject and the research is the consent document and the principal risk is a breach of confidentiality. potential subjects might find some of the research questions embarrassing, personal, or intrusivethe subjects are literate in their own language; however, they do not read, write, or speak english

Steven pinker states that an important difference exists between men and women in:

According to machiavelli what will happen to a leader when things go wrong and he is in need of support