A country’s total score on the KidsRights Index (T) has been calculated as the geometric average of the scores of the five domains. Each domain has the same weight. The scores for each domain are calculated as the average value of the indicators. All indicators have been standardized using a linear scaling technique:
where is the score on indicator i of country j, and Max and Min represent the maximum and minimum scores on this indicator. This scaling technique ensures that the score for each indicator ranges between 0 and 1. All indicators were coded positively. This means that a higher score for each indicator can be associated with a positive contribution to the rights of children.
As of 2016 the KidsRights Index took an improved approach when dealing with missing values. The score for a domain is not calculated if more than half of the indicators of that domain have a missing value. A country is not included in the overall Index if the score on domain 5 ‘Child Rights Environment’ is missing. A country is also not included if more than half of the domain scores are missing (e.g. when three or more domains are missing).
The advantage of this new approach is that the scores for the domains and the total Index are now completely based on the most recent available data (there are no imputations of missing values based on historical data). Moreover, the restrictions on calculating the domain scores and the overall score make sure that these scores are based on a substantial number of indicators. In the previous versions of the KidsRights Index, the score of countries with many missing values could be based on just a small number of indicators, and therefore be sensitive for very high or low scoring based on a few indicators.
For domain 5, the information derived from the qualitative Concluding Observations was initially scored on a scale between 1 and 3. Assignment of the actual score to each sub-indicator was based on the language used by the CRC Committee in the Concluding Observations: predominantly negative language = 1, a combination of positive and negative language = 2, predominantly positive language = 3. The resulting final scores have also been standardized by using the above mentioned linear scaling technique.
The index is a ranked country list, with colour-coding indicating relevant clusters of rankings. There are five different clusters which display a more or less similar performance level, as each cluster concerns countries for which the scores belong to the same distribution. Within a cluster the scores of countries are thus more similar then across clusters. The clusters are expressed in coloured world maps.
If a country ranks 16-31 for example, it means that a country shares a rank with several countries that received the exact same score. Only when scores are different a country can be ranked individually.