Tracking respondents is the most vital part in longitudinal research. We are an expert in tracking. Our longitudinal studies have an attrition rate of less than 2%. We provide the following services: 

• Write data collection protocol
• Set up reproducible documentation
• Write the high-frequency check and backcheck codes
• Digitize questionnaire into SurveyCTO platform
• Collect high-quality data and clean the data with reproducible codes
• Track study participants in follow-up rounds
• Help researchers identify suitable funding and apply to those funding
• Engage relevant policymakers