Ratio scales The temperature example Educational level as measured in years of In the commonly used Fahrenheit and schooling would appear to be measured at Celsius scales, zero is arbitrarily selected the interval level, but it is really an even and it is possible to have below-zero higher level of measurement known as the temperatures In the Kelvin scale, however, ratio level zeo·K(-273·c) is called absolute zero In theory, it cannot get any colder than absolute zero so there are no below-zero Ratio scales Ratio scales Interval and ratio levels are nearly identical In the social sciences, many variables The difference between the two is the above the ordinal level of measurement nature of the meaning of zero. In interval are actually ratio level. We encounter few data, zero is an arbitrary point, whereas in examples where zero is arbitrarily ratio data. zero is an absolute zero assigned meaning a complete lack of the variable More examples of ratio data are monetary baht, lira being measured units such as dollars measurement of size such as weight, height. or a11 21 Ratio scales • Educational level as measured in years of schooling would appear to be measured at the interval level, but it is really an even higher level of measurement known as the ratio level. 22 Ratio scales • Interval and ratio levels are nearly identical. The difference between the two is the nature of the meaning of zero. In interval data, zero is an arbitrary point, whereas in ratio data, zero is an absolute zero, meaning a complete lack of the variable being measured. 12 23 The temperature example • In the commonly used Fahrenheit and Celsius scales, zero is arbitrarily selected and it is possible to have below-zero temperatures. In the Kelvin scale, however, zero 。K (-273。C) is called absolute zero. In theory, it cannot get any colder than absolute zero, so there are no below-zero readings on the Kelvin scale. 24 Ratio scales • In the social sciences, many variables above the ordinal level of measurement are actually ratio level. We encounter few examples where zero is arbitrarily assigned. • More examples of ratio data are monetary units such as dollars, cents, baht, lira, measurement of size such as weight, height, or age