2.2. Expert Workshops and the Expert Delphi Surveys

The expert panel consisted of individuals who have worked in the fields of food and nutrition, food policy, and food inequality for more than 10 years. Some experts were selected from the list of the policy advisory group for the government of Seoul. A total of three expert workshops were conducted, during which the definition and three main domains of food literacy were specified, a set of questions measuring food literacy was developed, and a panel of experts was selected to create a draft Delphi expert survey.

The content validity ratio (CVR) was calculated to verify the validity of the Delphi survey:

where Ne is the number of panel experts who responded that the item was important, and N is the total number of expert panelists who responded. The CVR calculates a minimum value according to the number of panels, and the item content is judged as valid if it meets or exceeds the minimum value [20].

The Delphi survey panel was active in the areas of production, manufacturing/processing/packaging, consumption, distribution/sales, and environment in the food system. A total of 15 experts were selected for the panel, which comprised 10 practitioners/policy experts and 5 researchers from academia. The Delphi survey was conducted twice. The first survey focused on opinions surrounding the definition of the three main domains of food literacy, opinions on the necessity and revision of food literacy questionnaires, and open-ended questions as free opinions for each domain. The second survey focused on the specific items for measuring food literacy based on the revised definitions and three main domains and on calculating the CVR of the suggested items.