This thesis utilises teachers’ reflections regarding their experiences of science outreach activities, they have encountered and identify features of these programmes that attracts schools to engage (or not engage) with these extra-curricular events. This is useful as science outreach work is considered a fun and satisfying venture which can enhance the learning experience, spark scientific interest in learners which can promote further engagement within the subject (Shanahan et al, 2011). Teachers are also an important group to focus upon within this field, as teachers are gatekeepers to these experiences. However, wider research warns that there is little evidence to suggest whether these types of activities achieve their overarching goal; to encourage people to enter and persist within science careers (Banerjee, 2018; Bogue et al, 2013; Van De Hurk et al, 2019). Therefore, this PhD aims to further explore which type of outreach activities participants believe to be the most successful in enthusing learners in science, to provide recommendations as to the future designs of these programmes. To do so, this PhD was divided into two Phases and collected data from participants across all formal educational levels (eg. from primary to college in the context of England). Phase One involved conducting questionnaires (n=52) and interviews (n=8) and generated both quantitative and qualitative data. Standard statistical analysis was used to determine who participants felt that science outreach should be aimed at and thematic analysis (Braun and Clarke, 2006) of the qualitative data provided a more detailed understanding of what teacher’s expectations are with regards to these programmes. Data revealed that despite wider research stating that children formed interests at a young age (Oppermann et al, 2018), participants felt that outreach was more important at higher educational levels. Participants did however agree that it was of equal important for both genders and those from a lower socio-economic background. Responses from the open-questions and interviews also revealed that although teachers value these types of activities to assist with the formal science curriculum, barriers such as time and cost may limit their engagement with these programmes. These findings, along with more focused wider literature, were then used to develop a preliminary model for the ‘optimum’ delivery of science outreach activities. Phase Two was designed to further refine the proposed model using principles of Modified Grounded Theory via conducting focus groups (n=4). As part of these focus groups participants were also specifically asked which aspects of the model would be most beneficial for those learning from lower socio-economic backgrounds. Findings from this phase of the PhD study indicated that the key to effective outreach work in science is to ensure that clear objectives are defined at the start of the design process to ensure that all key stakeholders such as teachers, parents and learners are included. It is anticipated that if this approach to developing outreach activities in science is adopted it will assist with removing some of the barriers to engaging with these events to increase engagement. Participants also perceived that by focusing on careers, making science relevant to the learners, providing relatable role models and engaging parents in science outreach events, would make these programmes more impactful, especially for those learners from disadvantaged background. When designing this model, a pragmatist approach was adopted as this allowed the researcher to focus on the strengths of the different paradigms (Johnson & Onwuegbuzie, 2004). This ensured that the data collected provided the most suitable information to create the ‘optimum science outreach model for lasting impact’ which translates data into a framework. Using this model as a framework will allow outreach providers to draw upon findings from this study more readily when designing age-appropriate outreach activities. Thus, this PhD provides further understanding as to what motivates teachers to engage with science outreach activities, which can be used to inform the design of subsequent programmes.