Trying to understand PISA is analogous to the parable of the blind men and the elephant. There are many facets of the PISA program, and thus many ways to both applaud and critique this ambitious international program of assessment that has gained enormous importance in the crafting of contemporary educational policy. One of the facets discussed in this paper is the issue of the comparability of the cognitions elicited by items across national and linguistic cultures. Valid interpretations of PISA results cannot proceed without assurance that items across nations are interpreted in the same way. A second facet examined is the association of PISA with economic outcomes for nations, still an unsettled area of importance. A third facet discussed is the search in PISA data for universally applicable instructional techniques, a possible will-o-the-wisp. A fourth facet examined are differences in cross-national attitudes toward the PISA subjects and how those affect test scores. Given these many facets of the program, a fifth facet that is arguably the most important of all the issues associated with PISA is discussed, namely the interpretation of PISA scores.