Most of the data in Government at a Glance Southeast Asia 2019 were collected from government officials by the OECD via specifically defined surveys (Budgeting Practices and Procedures, Digital Government, Open Government and Open Government Data, and Strategic Human Resources). As such, they represent either official government statistics or the country’s own assessments of current practices and procedures. To the extent possible, OECD data collection instruments use standardised definitions and common units of measure. However, biases can occur in that countries may interpret and answer questions differently and/or may not answer the questions completely objectively. In general, the direction of the bias is known but not necessarily its extent. To try and minimise these biases, the OECD cleaned and verified the collected data by following up with countries when there were potential inconsistencies and outliers. This has been mainly achieved thanks to the OECD’s knowledge through previous work in the region and local presence in the countries under study. In addition, respondents have been asked to provide additional evidence to validate their answers which, in turn, have been verified with other external and additional sources whenever available. Data collection began in 2017 and in six countries – Cambodia, Indonesia, Malaysia, the Philippines, Singapore and Thailand (for the Budgeting Practices and Procedures survey data collection started in 2015 and was updated in 2018). Data collection began in 2018 in the remaining four countries – Brunei Darussalam, the Lao People’s Democratic Republic, Myanmar and Viet Nam. All data were finalised after a thorough data cleaning process for all countries in 2018.