To meet project objectives, the EU-funded IRIS project identified specific questions that needed addressing: How are educational choices made? What are women's perceptions of science, technology, engineering and mathematics (STEM)? Have efforts to recruit more women STEM students been fruitful? How do countries, institutions and genders differ in terms of opt-out rates? To answer these and related questions, data were collected from questionnaires completed by first-year students. The data were complemented by literature reviews and smaller qualitative and quantitative studies. Drawing on different theoretical frameworks to explore how young people process educational choices and their relationship to STEM, almost 7 000 STEM students from 8 STEM disciplines in 5 European countries completed the IRIS questionnaire. The instrument sought to gather information on related subjects: science experiences from school, inspiration for choice of education, future job expectations, first-year experiences, and attitudes to gender equity in the particular field. Project activities were successful in generating insights into the topics under investigation. These have been published in a summary, with results spread across six categories. They reveal, among other findings, that choice is connected to intrinsic value, and that school experiences have a great impact on choice. Also, recruitment initiatives need to be developed and improved over time to attract student interest and respond to expectations of success. The IRIS team has enhanced efforts aimed at realising a larger and more diverse STEM workforce that will contribute to growth in important areas like medical treatment, renewable energy, agricultural technology and transport.