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.
Z-scores (standard scores) raw scores stated in standard deviation terms. a measure of how many standard deviations a given raw score is from the mean. A negative number (e.g. -1) means the score falls below the mean. 0 = the mean. shape of the distribution does not change when scores changed to z-scores (linear transformation)