Students all over the world face similar challenges analyzing science texts as the language of science contains abstract symbols and complex terms. The challenges are particularly acute for California traditionally underserved high school students partially due to insufficient modifications and accommodations. To facilitate equitable participation in STEM (science, technology, engineering, mathematics), this intervention is designed to enhance student’s confidence in decoding science text at the organizational level. The action research investigated the relative efficacy of intervention via Diagramming and Text Marking, a subset of Directed Activities Related to Texts (DARTs). Review of the literature validated DARTs as an effective strategy in supporting students for learning-to-read and reading-to-learn science texts. Cognitive, affective and attitudinal feedback data, quantitative and qualitative, were collected during the 3-week intervention implementation. Analysis of intervention’s outcome indicated a relatively statistically significant positive effect for Text Marking over Diagramming. A possible implication, pending further study, would be modifications that reverse the conventional high school physics textbook approach for problem-solving in which diagramming has been typically placed ahead of text marking.