Two-year-old Laura dropped a block into her toy box. She then dropped a cup, a car, and a doll—some gently, and some with force. Laura’s modification of her dropping scheme is an example of .

Why do governments supply public goods and services instead of selling them to those people who use them

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period.the collection of data, by a playground designer hired by the superintendent of schools, about the physical dimensions of school playgrounds, presence of fencing, and the kinds of equipment currently provided.a feasibility study for implementing a year-round school program, focusing on economic issues such a facilities utilization and transportation costs.an analysis of aggregate data comparing statewide high school graduation rates provided by the state department of public instruction, using county tax information.

The primary purpose of a certificate of confidentiality is to: allow law enforcement to investigate abuse cases.protect researchers from disclosing conflicts of interest.prevent subjects from knowing the purpose of a study.protect identifiable research information from compelled disclosure.