David's expertise is designing interventions in survey questions to improve judgments. Examples of his work include:
- Designing the questions used in constructing the Scottish and Irish Consumer Sentiment Indices
- An experiment that led the state of Massachusetts to redesign the questions that open its online marketplace for health insurance, the Massachusetts Connector
- Designing expenditure questions that are used by the Irish Revenue Commissioners and leading market researchers
- Designing an intervention to increase sustainable transport use that was rolled out by the Irish National Transport Authority.