Tom started the process of selecting a new system for the firm and he is weighing all of the various issues that need to be considered and the resources he has at his disposal as he makes this important decision. As Tom prepares to narrow the field in his selection of a new system, he wants a quick refresher on the difference between a request for proposal (RFP) and a request for quotation (RFQ). If he needs a request for proposal (RFP), Simone will write it, and if he needs an RFQ, Marny is responsible for writing that. Which of the following is true?​

Dr. X wants to recruit the maximum number of subjects. She should:

Precision of a variable is:

Once a system becomes stable, maintenance costs usually remain low and involve minor _____ maintenance.​

Confounding can be:

Individuals are divided into sub-groups on the basis of specified characteristics  and then random samples are selected from each sub-group. This type of sampling is:

The association between smoking and dental caries has been the subject of previous epidemiological studies. Cohort studies have found no association, while at least one case-control study has found a positive association. Possible explanations for the different results in case-control and cohort studies of this topic include:

Researchers were conducting a research study to determine the clinical  attachment loss in a sample of adult smokers. The examiner who was  conducting these measurements left the University in the middle of the study.    The Principal Investigator (PI) appointed a new examiner to conduct the  remaining portion of the examinations. To assure consistency in the examinations the new examiner should be:

The investigators were assessing severity of periodontal disease among a convenience sample of older adults in the city of Rochester. They found that individuals who were African-American had much greater mean attachment loss than older adults who were Caucasian and Hispanic. To assess these differences statistically one can use:

When using multiple tests to screen for a disease, there is a loss in net sensitivity and a gain in net specificity in: