Grids are commonly used, particularly in web surveys, when multiple items share the same response options. Previous research has found that displaying multiple items in a single grid yields higher correlated responses and less item differentiation compared to using either fewer grid items per screen or having one single item per screen (Tourangeau et al, 2004, Yan, 2005, Toepel et al, 2009). Also, responses in a grid appear to be less consistent when the item definitions are reversed, although the difference is not significant (Callegaro et al, 2009). The aim of our study is to investigate how the number of grid items and screens affect response behavior and data quality given a large number of overall items (12). Users who opt into a survey linked from the Google Maps interface will be shown one of five grid format conditions from a split ballot experiment. Across all groups, users will be presented with only one grid per screen, but the number of screens and grid-items will vary; in the first group, users will be presented with one twelve-item grid, in the second group, two-six item grids, in the third group, three four-item grids, and so forth. Additionally, all twelve grid-items will be randomized across screens and all grids will be presented with the same fully labeled 5-point response scale. We hypothesize that the distribution of answers will differ across experimental conditions and drop-offs and item non-response will increase with larger grids. Additionally, we hypothesize that grids with more items will lead to more measurement error as indicated by a higher rate of inconsistency, especially when the meaning of some grid-items is reversed (i.e confusing vs. simple).