John johnson used nonrandom sampling in his study of successful scientists. he knew most got excellent grades in high school and college, excelled in mathematics, and had a strong interest in science from a young age. for his study, he was interested in sampling those who were successful as adult scientists, but did poorly in high school, did average or worse in math classes, and showed little interest in science until they reached college or later in life. what type of sampling was he using?

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

When arriving at a navigation lock what is the order of priority

Why do you think that historians use the word “revolution” to describe important changes in agriculture? how did the green revolution and other agricultural revolutions change the lives of billions of people? < < read less