Since their development in the 2008 report, these ladders allow the JMP to show what is considered improved and unimproved in a more refined way than the only pass/fail former presentation without changing the MDG definitions. These ladder currently allows a disaggregated analysis of trends in a four rung ladder for drinking-water and sanitation as shown to the right.
The drinking-water ladder has been prepared showing the global proportion of those using drinking water directly collected from surface water (like river, ponds, lakes etc.), those using other unimproved water sources, those using "improved" sources other than piped household connections and those benefiting from household connections in a dwelling, plot or yard.
Similarly for sanitation, this gives an understanding of the proportion of population globally with no sanitation facilities at all, of those reliant on technologies defined by the JMP as "unimproved," of those sharing sanitation facilities of otherwise acceptable technology, and those using "improved" sanitation facilities.
These refinements allow countries and the international community to form a clearer understanding of the situation of access to water and sanitation (learn more about the JMP and country collaborations). As definitional differences are often the prime cause for discrepancies in the estimates between country figures and the JMP estimates, the ladder tries to show precisely where this discrepancy is coming from. This new way of analysing access has become an essential tool for data reconciliation at national level, between the different stakeholders and especially sector agencies and national statistics offices, as well as between the national level and the JMP.