Everyone must wear medical grade gloves in a sterile field. A sterile field is usually used during surgery. A sterile syringe and vial of medication. Surgical hand scrubs remove most bacteria from the skin before gloves are put on.
Standard score. In statistics, the standard score is the signed number of standard deviations by which the value of an observation or data point is above the mean value of what is being observed or measured. Observed values above the mean have positive standard scores, while values below the mean have negative standard scores. The standard score is a dimensionless quantity obtained by subtracting the population mean from an individual raw score and then dividing the difference by the population standard deviation.
Figure 1. On many standardized assessments the publishers base the standard score on a distribution with a mean of 100 and a standard deviation of 15. A score of 100 on such a test (e.g., WJIIIDRB) means that if the student scored in the middle of the distribution (Mercer & Pullen, 2009). standard score is based on a normal distrbution with a mean and a standard deviation (see Figure 1). The black line at the center of the distribution represents the mean. The turquoise lines represent standard deviations. Figure 1.