Clinical Chemistry Exam 1 2024 With Complete Solutions

Accuracy - The closeness with which a measurement comes to the true value Precision - The degree of reproducibility in the measurement of a substance Mean - Sum of all of a set divided by the number in the set (average) Median - The point on the scale that has equal number of observations above and below (even number, take the two-center numbers add and divide by 2) Mode - The value in a set that occurs most frequently Norm. Distribution - The theoretical bell-shaped curve based in the Gaussian Law of Errors. Normal Frequency Curve Standard Deviation - A statistical calculation that measures the scatter of sample values around the mean. (The acceptable variation from the mean) The clinical lab uses 2 SD as an acceptable variation in a method of analysis. Confidence Limits - An expression of the amount of error that can be allowed in the recovery of a value without affecting the validity Coefficient of Variation - An expression of standard deviation as a percentage of the mean A way of comparing the precision of different methods of assay Also a better way to check the precision at various levels of concentration Bias - A constant departure of quantity from the true value due to outside influence Random Error - An error that does not occur in any regular predictable pattern Systematic Error - A regularly occurring error that is constant, predictable, and traceable Shift - Six to ten control values fall consecutively above or below the mean Trend - An uninterrupted rise or decline away from the mean Primary Standard - A solution generally containing a single purified solute in a pure solvent The true value of the solvent is known by exact measurement (Analytical Balance) Used to "set" or calibrate an instrument Secondary Standard - A material with an established value(s) determined by assay against a primary standard It may contain one or more constituents Control - Usually pooled human sera containing a number of substances used to verify the precision of a method Mole - Atomic Weight