Question: I'm looking for a tool that can detect and prevent fraudulent respondents in online surveys.

If you're looking for a service to spot and block fraudulent respondents in online surveys, Verisoul is a full-featured option. It automates laborious processes and centralizes vendor activity to keep fraud at bay. The service evaluates a range of signals, including device fingerprinting, geolocation and phone/email intelligence, to ensure legitimate users are participating. It can make automated decisions and can be integrated with a variety of industries, making it adaptable to a wide range of user populations.

Another good option is Imperium, which offers a range of data quality tools designed to ensure survey data is trustworthy and reliable. Imperium helps screen out duplicate respondents and fraudsters with tools like RegGuard for ID verification and RelevantID for behavioral monitoring. Its cloud-based service includes tools like Address Correction and Real Mail to ensure better deliverability and screen out bogus email addresses, and it's a good overall security option for market researchers.

For a wider range of research needs, CloudResearch offers a collection of tools, including Sentry for fraud detection. The service is designed to let researchers oversee studies while ensuring data quality and screening out fraudulent respondents. CloudResearch's service is geared for social science, market research and nonprofit projects, and can handle recruiting participants and ensuring data quality.

Last, IPQS offers an AI-based fraud detection service that can screen out fraudulent activity in online surveys. With sophisticated algorithms that evaluate more than 300 data points, IPQS delivers real-time insights and accurate risk assessments. The service offers features like proxy and VPN detection, email verification and fraud scoring, and can be used to protect data and prevent fraudulent transactions.