This poster shares preliminary results from our first cohort of participants toward answering the question "How does online mentoring of student-led plant biology investigations impact high school students' views of scientists? This is just one aspect of the overall research project, which involves 1) a conceptual replication of a previous efficacy study (DIgging Deeper, NSF #2010556) on the impact of a student-teacher-scientist partnership online mentoring program (Taylor et al. 2022) using updated measures of high school students’ achievement, motivation to study plants, and counter-stereotypical attitudes about scientists, 2) the development of an equivalent, high-quality online version of the professional development workshop used in Digging Deeper to prepare teachers and liaisons to implement the program with students, and 3) a comparison of the relative efficacy and cost-effectiveness of the in-person and online professional development formats to support the intervention and impact student outcomes.