If survey respondents do not interpret a question as it was intended, they may, in effect, answer the wrong question, increasing the chances of inaccurate data. Researchers can bring respondents’ interpretations into alignment with what is intended by defining the terms that respondents might misunderstand. This dissertation explores strategies to increase response alignment with definitions in online surveys. In particular, I compare the impact of unimodal (either spoken or textual) to multimodal (both spoken and textual) definitions on question interpretation and, indirectly, response quality. These definitions can be further categorized as conventional or optimized for the mode in which they are presented (for textual definitions, fewer words than in conventional definitions with key information made visually salient and easier for respondents to grasp; for spoken definitions, a shorter, more colloquial style of speaking). The effectiveness of conventional and optimized definitions are compared, as well as the effectiveness of unimodal and multimodal definitions.

Amazon MTurk workers were randomly assigned to one of six definition conditions in a 2x3 design: conventional or optimized definitions, presented in a spoken, textual, or multimodal (both spoken and textual) format. While responses for unimodal optimized and conventional definitions were similar, multimodal definitions, and particularly multimodal optimized definitions, resulted in responses with greater alignment with definitions. Although complementary information presented in different modes can increase comprehension and lead to increased data quality, redundant or otherwise untailored multimodal information may not have the same positive effects. Even as not all respondents complied with instructions to read and/or listen to definitions, the compliance rates and effectiveness of multimodal presentation were sufficiently high to show improvements in data quality, and the effectiveness of multimodal definitions increased when only compliant observations were considered.

Multimodal communication in a typically visual medium (such as web surveys) may increase the amount of time needed to complete a questionnaire, but respondents did not consider their use to be burdensome or otherwise unsatisfactory. While further techniques could be used to help increase respondent compliance with instructions, this study suggests that multimodal definitions, when thoughtfully designed, can improve data quality without negatively impacting respondents.