The Public Radio Program Directors Association (PRPD) sponsored the Core Values Project. It is aimed at clearly defining the fundamental appeal of public radio programming. Here is a handy one page summary of the findings: sample-core-values-news
The project worked with PRNDI to apply the core values to local news programming. It produced a PRPD-PRNDI Core Values Toolkit
The project grew to cover other formats and more case studies. For the most complete set of reports and case studies, visit the Core Values repository on the PRPD website.