Empirical refinements of a molecular genetics learning progression: The molecular constructs

Abstract

This article describes revisions to four of the eight constructs of the Duncan molecular genetics learning progression [Duncan, Rogat, & Yarden, (2009)]. As learning progressions remain hypothetical models until validated by multiple rounds of empirical studies, these revisions are an important step toward validating the progression. Our revisions are based on empirical data obtained from tenth grade students in three classroom contexts (n ¼ 121); although our study was done with students at the upper bounds of the progression, students held naive ideas prior to instruction which allowed us to track their ideas through all the levels of each construct during the course of one academic year. We revised the four constructs that center around the molecular model of genetics using students' pre/post assessments and interviews. We found that tenth grade students do hold ideas consistent with the hypothesized levels in the progression as well as several intermediate ideas not included. Our revisions include adding student ideas that are important conceptual stepping stones in each construct as well as other modifications such as splitting and combining levels, moving ideas to other constructs, changing the conceptual progression of a construct and splitting a construct. Along with the revisions, we identified challenges in each construct. Even after instruction, students had difficulties understanding that genes code for proteins, that proteins connect genes and traits, and how differential gene expression leads to different repertoires of proteins inside of specialized cells. Our findings indicate that classroom instruction should focus more on proteins: how they are created, what their functions are, and how cells express different proteins.

Development and Validation of the Learning Progression-Based Assessment of Modern Genetics in a High School Context

“…Sample items based on a progression for matter and the atomic molecular theory were developed by Smith, Wiser, Anderson, and Krajcik (); open‐ended items and interview questions based on a progression for carbon cycling were developed by Jin, Choi, and Anderson (); open‐ended items and interview questions based on a genetics LP were developed by Duncan et al. () and Todd and Kenyon (); Songer et al. () developed multiple‐choice items based on a biodiversity progression; Furtak, Morrison, and Kroog () developed the Daphne Assessment of Natural Selection, a multiple‐choice assessment linked to a progression for natural selection; and Neumann et al.…”

“…Despite the call for useful assessments aligned to progressions, few progression‐based assessments have been created and even fewer have been psychometrically validated. Building on our previous work in genetics learning progressions (Todd & Kenyon, ), we focused on creating and validating an assessment tied to our revisions of the Duncan et al. () genetics learning progression.…”

Investigating a learning progression for energy ideas from upper elementary through high school

“…Researchers have described learning progressions for physical science topics such as matter (e.g., Hadenfeldt, Neumann, Bernholt, Liu & Parchmann, 2016) and energy (e.g., Neumann, Viering, Boone, & Fischer, 2013), earth science topics such as the water cycle (Forbes, Zangori, & Schwarz, 2015) and climate change (e.g., Breslyn, McGinnis, McDonald, & Hestness, 2016), and life science topics such as genetics (e.g., Todd & Kenyon, 2015) and ecosystems (e.g., Hokayem & Gotwals, 2016). In addition to learning progressions in these content areas, researchers have also described learning progressions for science practices such as argumentation (e.g., Osborne et al, 2016).…”

Trabajar genética y enfermedades en secundaria integrando la modelización y la argumentación científica

“…La genética es uno de los campos de la biología de mayor dificultad para el alumnado (Todd y Kenyon 2015). La literatura agrupa estas dificultades en cinco dominios: 1) el vocabulario y la terminología específica; 2) el contenido matemático de las tareas de genética mendeliana; 3) los procesos citológicos; 4) la naturaleza abstracta de la genética y la manera de abordarse en el currículum, 5) su complejidad, que implica procesos a nivel macro y micro.…”