An engineering design curriculum that introduces functional modeling methods is believed to enhance the ability to abstract complex systems, assist during the concept generation phase of design, and reduce design fixation. To that end, a variety of techniques for considering function during design have been proposed in the literature, yet there are a lack of validated approaches for teaching students to generate functional models and no reliable method for the assessment of functional models. This paper presents a study investigating students' ability to generate functional models during a homework assignment; the study includes three different treatment conditions: (1) students who receive only a lecture on functional modeling, (2) students who receive a lecture on functional modeling as well as a step-by-step example, and (3) students who receive a lecture, a step-by-step example, and an algorithmic approach with grammar rules. The experiment was conducted in a cornerstone, undergraduate engineering design course, and consequently, was the students' first exposure to functional modeling. To assess student generated functional models across all three conditions, an 18 question functional model scoring rubric was developed based on flow-based functional modeling standards. Use of the rubric to assess the student generated functional models resulted in high inter-rater agreement for total score. Results show that students receiving the step-by-step example perform as well as students receiving the step-by-step example and an algorithmic approach with grammar rules; both groups perform better than the lecture-only group.