Final answer:
The researchers should use factor analysis to reduce the amount of data to a few underlying dimensions.
Step-by-step explanation:
The researchers should use factor analysis to reduce the amount of data to a few underlying dimensions. Factor analysis is a statistical technique that examines the interrelationships among a set of variables and identifies the underlying factors that explain the patterns of correlation.
With the extensive survey data collected on the iPhone's features and benefits, factor analysis can help identify the underlying dimensions or factors that explain the respondents' ratings on the twenty different features. This technique can reduce the data to a smaller number of factors, providing a more concise and interpretable representation of the data.