Moment magnitude scale of formula_33 are the same for all earthquakes, one can consider as a measure of the potential energy change Δ"W" caused by earthquakes. Similarly, if one assumes formula_34 is the same for all earthquakes, one can consider as a measure of the energy "E" radiated by earthquakes. Under these assumptions, the following formula, obtained by solving for the equation defining , allows one to assess the ratio formula_35 of energy release (potential or radiated) between two earthquakes of different moment magnitudes, formula_36 and formula_37: As with the Richter scale, an increase of one step on the logarithmic scale of moment
Rating scale at the ordinal level. Numbers indicate the relative position of items, but not the magnitude of difference. Attitude and opinion scales are usually ordinal; one example is a Likert response scale: Some data are measured at the interval level. Numbers indicate the magnitude of difference between items, but there is no absolute zero point. A good example is a Fahrenheit/Celsius temperature scale where the differences between numbers matter, but placement of zero does not. Some data are measured at the ratio level. Numbers indicate magnitude of difference and there is a fixed zero point. Ratios can be calculated. Examples include