Soda X is natural. Soda X is good for you, etc. The respondent has not been given the option to say that he or she does not know if the soda is natural or good for you. The respondent should be given the option to say that she or he does not know if the attribute applies to the product. Make scales culturally compatible.
Some cultures find scales easier to use than others.
Mexicans, for example, are quite familiar with the notion that children in school are graded on a 0 to 10 scale. The use of a long battery of items to detect perceptions and opinions may not be as useful in some cultures as they are in the general market. When a long list of attributes is read to respondents who share a specific cultural background, many respondents are likely to give the same kind of answer. Hispanic respondents, for example, are known for using extremes of scales. After a few attributes are rated, they tend to settle on a high or low value and continue that way.