Rarely, proton pump inhibitors (such as omeprazole) have caused vitamin B-12 deficiency. The risk is increased if they are taken every day for a long time (3 years or longer). Tell your doctor right away if you develop symptoms of vitamin B-12 deficiency (such as unusual weakness, sore tongue, or numbness/tingling of the hands/feet).
Stability reliability refers to the consistency of students' scores when a test is administered to the same students on two different occasions. Alternate-form reliability describes the consistency of students' performances on two different (hopefully equivalent) versions of the same test.
The z-score is only defined if one knows the population parameters; if one only has a sample set, then the analogous computation with sample mean and sample standard deviation yields the Student's t-statistic.hus, a positive standard score indicates a datum above the mean, while a negative standard score indicates a datum below the mean.