Are 7-point Likert scales preferable to 5-point scales in language research?

This study compared the information yield of 5- and 7-point Likert scales in language research, motivated by theoretical arguments concerning the limits of working memory and response category confusion (i.e., that participants may not be able to attend to more than five response categories at once). An empirical investigation of subjective word frequency ratings confirmed that the 7-point scale did not produce estimates of frequency that were more highly correlated with objective frequency counts than those produced by the 5-point scale. However, this equivalence was not due to the hypothesized limits of human working memory capacity but rather to the equivalent precision achieved when estimating a regression line with five versus seven data points. These conclusions apply to rating scales that utilize the full variable range. In contexts where the response range utilizes only part of the Likert scale, the scale's effective precision may drop significantly, making more refined scales beneficial. Consequently, since the 7-point scale did not demonstrably increase participant effort or confusion, and since not all research questions involve the full Likert scale, researchers may prefer the 7-point scale for its versatility.