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Calendar of Events
Each of the international large-scale studies has its own project schedule and cycle, but all have a field test, main data collection, and release of results. This Calendar of IAP Studies provides an overview of all the different studies' schedules across the next 3 years.

Field Test. As part of the development of each study, a field test is conducted to try out (a) all assessment and background questions and (b) the study's data collection operations, procedures, and equipment. Based on the results of the field test, questions that have problems are dropped or fixed and operational challenges are addressed in preparation for the main data collection.

Data Collection. The administration of each international assessment or survey is known as the main study data collection. Each study has its own required timeframe during which data must be collected to be internationally comparable.

Release of Results. After the administration of each international assessment or survey, all data are checked, compiled, and prepared for analyses (which includes deriving variables, creating indexes, and calculating weights and plausible values). Once these steps have been completed, analysis of the data is conducted and a report on the results prepared. This process typically takes 18 to 24 months from data collection to the release of international results.

Season 2019 2020 2021
TIMSS Data Collection
PIRLS Field Test
PIAAC Release of Results
TALIS Release of Results
IELS Release of Results
PIRLS Data Collection
TALIS Release of Results
PIAAC Field Test
ICILS Release of Results
PIAAC Release of Results
TIMSS Release of Results
PISA Field Test
PIAAC Field Test
PIAAC Data Collection
PISA Data Collection
PISA Release of Results
PIAAC Data Collection