  A major focus in the STEM public engagement sector concerns engaging with
young people, typically through schools. The aims of these interventions are
often to positively affect students' aspirations towards continuing STEM
education and ultimately into STEM-related careers. Most schools engagement
activities take the form of short one-off interventions that, while able to
achieve positive outcomes, are limited in the extent to which they can have
lasting impacts on aspirations. In this paper we discuss various different
emerging programmes of repeated interventions with young people, assessing what
impacts can realistically be expected. Short series of interventions appear
also to suffer some limitations in the types of impacts achievable. However,
deeper programmes that interact with both young people and those that influence
them over significant periods of time (months to years) seem to be more
effective in influencing aspirations. We discuss how developing a Theory of
Change and considering young people's wider learning ecologies are required in
enabling lasting impacts in a range of areas. Finally, we raise several
sector-wide challenges to implementing and evaluating these emerging
approaches.

Physics Education