The International Scale Interval Study: Improving the Comparability of Responses to Survey Questions About Happiness

This study is about survey questions on happiness using verbal response options, such as ‘very happy’ and ‘fairly happy’. The aim is to estimate what degrees of happiness are denoted by such terms in different questions and Languages. These degrees are expressed in numerical values on a 0 to 10 scale, which are then used to compute ‘transformed’ means and standard deviations.

Native speakers read survey questions on happiness that have been used in their country. For each question separately, they rate the relative value of each of the response options in their Language. They do that using an electronic ‘Scale Interval Recorder’. On their computer screen, participants see a vertical bar scale that they can partition into sections by shifting separation lines. The response options are presented next to the scale and move with the bars. Their task is to move the separation lines until they feel that the intervals on the scale correspond with the degree of happiness denoted by each of the verbal response options. The aim is to cover 74 Languages.

This study will allow a better use of the available survey data on happiness.