A total of 202 traditional and 138 ITBL students consented to participate in the study. Student sex was slightly more female in the ITBL course (Table 1). First generation status was similar among the two groups, but rank differed significantly, with more rank 4 students in ITBL. Ethnic identities among the students in both courses were mostly white, and although the ITBL course appears more diverse, this was not significantly different. Students in both groups had similar prior academic performance based on beginning of term (BOT) grade point averages (GPA) and first college chemistry grades, though ITBL students earned higher final course grades on average than the traditional lab students.

Total and individual PITS section scores were compared between the two courses, controlling for academic performance and demographics. A total of 136 traditional and 77 ITBL students had complete data for this analysis. ITBL-design lab reported significantly higher overall PITS scores (ANCOVA, Fig. 2). Of the six sections of the PITS, significantly higher scores were observed for the ITBL students in Project Ownership-Content, Project Ownership-Emotion, and Science Identity.

Persistence in the Sciences (PITS) total and subsection scores between traditional vs ITBL designed labs (A) and by race/gender total PITS (B) and PITS subsections (C). *0.001 < p < 0.008; **p < 0.001

The t-tests indicate significantly higher overall PITS scores in ITBL white males (+10.0%), white females (4.8%), non-white female (+7.6%), and first-generation students (+5.9%) compared to traditional lab design (Fig. 2). For white females, the largest PITS scores were in the Project Ownership-Content (+7.7%) and Project Ownership-Emotion (+7.5%) categories for students in ITBL over traditional labs. ITBL non-white females reported higher scores in the Science Identity (+11%) and Project Ownership-Emotion (+11.6%) categories. For white male students, Project Ownership-Content indicated some of the largest differences between ITBL and traditional labs (+12.5% points). ITBL first-generation students had the greatest enhancement in the Project Ownership-Content (+9.2%) and the Project Ownership-Emotion categories (+12.7%, Fig. 2). While non-white males in ITBL labs demonstrated positive trends in PITS categories, they did not achieve statistically significant differences. ITBL continuing generation students also had significantly higher PITS scores than traditional students in the Project Ownership-Content (+7.6%), Project Ownership-Emotion (+7.6%), Science Identity (+6.2%), and Networking (+7.0%) categories (Fig. 3).

PITS score: total (A) and subsection (B) scores between traditional and ITBL designed labs by first-generation college student status. Non-1st Gen, continuous generation. *0.001 < p < 0.008; **p < 0.001

For the four parts of the open-ended student responses, Cohen’s kappa for the Autumn 2021 data ranged from .142 to .767. Low agreement (kappa = .142) was observed for Code 2 because there were disagreements about the existence of a second code. For Code 1 (.651), STEM (.574), and Scientist (.767), kappa indicates moderate to substantial agreement among the two raters.10 The interrater reliability for the Spring 2022 responses indicated greater consensus with the second round of coding (Code 1 = .591, Code 2 = .547, STEM = .713, Scientist = .846).

For the open-ended question, 155 traditional students and 84 ITBL students provided responses. Students were categorized into Scientist, Not a scientist, Both (a scientist and not a scientist), and Unknown. A chi-square test indicates these groups are different among the two lab types (p = .015). ITBL students had a higher incidence in science identity (76.2% vs 65.2%) because they Gained confidence (30.9% vs 18.7%; e.g., understood the science behind a lab experiment), saw Science as a way to contribute to society (13.1% vs 3.9%; e.g., saw the experiments applying to real-world problems in pharmacy), and very few ITBL students reported that they Disliked an aspect of the scientific process (2.3% vs 5.16%; e.g., disliked data analysis). For traditional lab students who identified as scientists, most responses were coded into one of four categories: Gained confidence, Liked an aspect of the scientific process (e.g., completing class related labs), had a Positive external experience (e.g., working in a research lab), and they felt Science is joyful/interesting (e.g., having a passion for science). Similarly, ITBL students identifying as Scientists most often identified the following reasons: Gained confidence, Liked an aspect of the scientific process, and had a Positive external experience. However, ITBL students more often referred to Science as a way to contribute to society (e.g., contributing to solving world problems) as contributing to their development of a science identity (Table 2). For students identifying as a Scientist, the majority (67.3% of traditional, 65.6% of ITBL) stated that the events supporting this took place inside a STEM classroom.

More students in the traditional lab (20.6% of traditional, 5.9% of ITBL) identified as Not a Scientist. Traditional lab students mentioned they had Experienced failure (e.g., experiment went “wrong”, they earned poor grades), they Disliked an aspect of the scientific process, or they Need to do “X” to be a scientist (e.g., they have not conducted “real” research yet) as reasons they were Not a scientist. While ITBL also cited the Need to do “X” to be a scientist, they differed from traditional lab students by providing examples of Negative external experiences (e.g., a bad internship experience) and having Self-doubt (e.g., feeling incompetent). The events contributing to students feeling like Not a Scientist most often took place (59.3% of traditional, 100% of ITBL) in the STEM classroom.

Several students in both groups identified as Both (5.8% of traditional, 10.7% of ITBL) a scientist and not a scientist. Traditional lab students most often cited having Experienced failure as the reason they are Not a scientist, and that Science is joyful/interesting for identifying as a Scientist. ITBL students in the Both category most frequently cited Self-doubt as the reason for identifying as Not a scientist and Gaining confidence for identifying as a Scientist. When the researchers could not discern the students’ responses or reasoning, they were assigned to the Unknown category (8.4% of traditional, 7.1% of ITBL).

In the traditional lab, 61.3% of non-white students identified as a Scientist, compared with 65.7% of white students. In ITBL, 62.5% of non-white students identified as a Scientist, compared with 84.6% of white students. In the traditional labs, non-white students explained they felt like a Scientist because they Liked an aspect of the scientific process and Gained confidence, which were also the top two reasons given by the non-white ITBL students who identified as a Scientist.