Explanation: Conventional approach used to evaluate measurement uncertainty is based on random error and systematic error. Systematic error follows Rectangular, Triangular or U-shaped distribution approach.

Explanation: Modern approach is accepted as an international procedure. It is useful even for those problems where limited observations are possible. It is problem specific and defines the method explicitly.

Explanation: Modern approach is based on Type A method and Type B method. When observations are taken under same measurement conditions, Type A method is used. In type B method of modern approach, the uncertainty in measurement is evaluated by the judgement of the available information.

Explanation: Modern approach defines the method explicitly and is problem specific. In those problems where only limited observations are possible, modern approach is very useful.

Explanation: Random errors are those which can be caused by little variation in the standard setting of position, operator errors in reading the display of instrument etc. Random error follows the normal frequency or Gaussian distribution approach.

Explanation: Random errors are those which are produced due to large number of fluctuating and unpredictable errors that are non controllable in nature. The main characteristic of random errors is standard deviation, used to determine maximum measuring error.

Explanation: Spread of possible random error values is determined by the maximum error. The maximum error for a measurement method is three times the standard deviation. The maximum error and standard deviation determine the accuracy of measurement.

Explanation: Systematic errors can be caused due to calibration errors, Stylus pressure, ambient conditions (Variation from ambient temperature, pressure etc), Avoidable errors (due to the effect of misalignment of centre of workpiece and parallax) and incorrect theory.

Explanation: The value of (Quality/cost) increases with the help of statistical methods which means offer same quality at low cost or good quality at same cost or both i.e. better quality and less cost. Convention approach which is based upon random errors for evaluating the uncertainty of measurement follow the statistical methods.

Explanation: Random errors can be caused by friction and may be due to play in the linkage of instruments. These errors are variable in sign and magnitude. These are sometimes negative and sometimes positive. Its sign cannot be predicted.