TABLE A1.

The three latent variables and their assessment items in PISA 2015.

1. Intrinsic motivation
ST094Q01NA	I have fun when I am learning <broad science>
ST094Q02NA	I like reading about <broad science> topics.
ST094Q03NA	I am happy working on <broad science> topics.
ST094Q04NA	I enjoy acquiring new knowledge in <broad science>.
ST094Q05NA	I am interested in learning about <broad science>.
2. Instrumental motivation
ST113Q01TA	Making an effort in my <school science> subject(s) is worth it because this will help me in the work I want to do later on
ST113Q02TA	What I learn in my <school science> subject(s) is important for me because I need this for what I want to do later on
ST113Q03TA	Studying my <school science> subject(s) is worthwhile for me because what I learn will improve my career prospects.
ST113Q04TA	Many things I learn in my <school science> subject(s) will help me to get a job.
3. Epistemic beliefs
ST131Q01NA	A good way to know if something is true is to do an experiment.
ST131Q03NA	How much do you disagree or agree with the statements below? Ideas in <broad science> sometimes change.
ST131Q04NA	Good answers are based on evidence from many different experiments.
ST131Q06NA	It is good to try experiments more than once to make sure of your findings.
ST131Q08NA	Sometimes <broad science> scientists change their minds about what is true
ST131Q11NA	The ideas in <broad science> science books sometimes change.