Fostering Understanding of Complex, Dynamic, Interactive Human Body Systems

The NSF-funded Human Body Systems (HBS) suite provides a systematically designed exemplar for fostering and assessing important science learning that integrates the core ideas, science practices, and cross-cutting concepts of NGSS performance expectations.  Our goal is to help high school biology students integrate and animate what they have learned into nested mental models of human body systems. In 3 instructional modules, students reason about tasks, generate and test predictions, and use evidence to revise their models. The benchmark assesses their ability to do so.

Our theoretical framework integrates model-based learning in science and complex systems within an iterative evidence-centered design process. Working with teacher co-developers, we specified the components, interactions, emergent behaviors of the complex systems underlying the core ideas, science practices, and cross-cutting concepts to be embodied in the IMs and tested in the benchmark. IMs provide tailored feedback that supports model-building and enables successful task completion. The benchmark assessment provides similar tasks but no feedback. All modules generate reports for students and teachers. At scales ranging from molecules to the whole body, students investigate the mechanisms by which the nested systems of the human body support whole body functions.

We conducted pilot testing in 4 schools with diverse populations to ensure the appropriateness of HBS modules for a range of students and to identify tasks and feedback in need of revision. Five teachers used HBS with their physiology, general and sheltered biology classes during Spring 2014. Of the 543 students enrolled in the HBS pilot classrooms, 491 completed the benchmark assessment; 305 completed all 3 IMs. Think-alouds were conducted with 36 students.

We analyzed student response data and think-alouds as well as internal and external reviews by multiple methods. IRT analyses of the benchmark assessment data indicated good fit, reliability, and discrimination.  Triangulating among internal and external reviews, think-alouds, and item responses patterns, we specified tasks for revision. Preliminary analyses comparing HBS use in physiology, general biology, and sheltered biology classes suggest both expected and unexpected differences in performance and use and highlight the need for model-based instruction.