Clicker use in introductory biology: Impacts on exam performance

In-class response systems, or clickers, are useful formative assessment tools that support learning by providing real-time feedback that can be used to correct misconceptions through peer discussion and instructor guidance. Previous research has shown that peer discussion improves conceptual understanding within a class period. In this study, we asked whether the benefits of peer discussion could be detected on a longer time scale. We asked exam questions that were isomorphic to in-class clicker questions and found students that participated in peer discussion scored higher than students that were not in class for the discussion. We also examined the effect of clicker question format. Clicker questions are typically asked in a multiple-choice (MC) format in which students identify one preferred answer; however, this format cannot identify students with mixed conceptions, where they simultaneously hold correct and incorrect ideas. Conversely, multiple-true-false (MTF) questions challenge students to separately evaluate each answer option, and thus have the potential to identify and correct mixed conceptions. We found no effect of clicker question format related to performance on isomorphic exam questions. Overall, clickers have a positive effect on student performance. And while MTF questions do not have additional benefits relative to MC questions, they are an effective formative assessment tool for identifying mixed conceptions among students and offer instructors an alternative method for implementing clicker pedagogy

Clicker use in introductory biology: Impacts on exam performance

In-class response systems, or clickers, are useful formative assessment tools that support learning by providing real-time feedback that can be used to correct misconceptions through peer discussion and instructor guidance. Previous research has shown that peer discussion improves conceptual understanding within a class period. In this study, we asked whether the benefits of peer discussion could be detected on a longer time scale. We asked exam questions that were isomorphic to in-class clicker questions and found students that participated in peer discussion scored higher than students that were not in class for the discussion. We also examined the effect of clicker question format. Clicker questions are typically asked in a multiple-choice (MC) format in which students identify one preferred answer; however, this format cannot identify students with mixed conceptions, where they simultaneously hold correct and incorrect ideas. Conversely, multiple-true-false (MTF) questions challenge students to separately evaluate each answer option, and thus have the potential to identify and correct mixed conceptions. We found no effect of clicker question format related to performance on isomorphic exam questions. Overall, clickers have a positive effect on student performance. And while MTF questions do not have additional benefits relative to MC questions, they are an effective formative assessment tool for identifying mixed conceptions among students and offer instructors an alternative method for implementing clicker pedagogy

How Administration Stakes and Settings Affect Student Behavior and Performance on a Biology Concept Assessment

Biology instructors use concept assessments in their courses to gauge student understanding of important disciplinary ideas. Instructors can choose to administer concept assessments based on participation (i.e., lower stakes) or the correctness of responses (i.e., higher stakes), and students can complete the assessment in an in-class or out-of-class setting. Different administration conditions may affect how students engage with and perform on concept assessments, thus influencing how instructors should interpret the resulting scores. Building on a validity framework, we collected data from 1578 undergraduate students over 5 years under five different administration conditions. We did not find significant differences in scores between lower-stakes in-class, higher-stakes in-class, and lower-stakes out-of-class conditions, indicating a degree of equivalence among these three options. We found that students were likely to spend more time and have higher scores in the higher-stakes out-of-class condition. However, we suggest that instructors cautiously interpret scores from this condition, as it may be associated with an increased use of external resources. Taken together, we highlight the lower-stakes out-of-class condition as a widely applicable option that produces outcomes similar to in-class conditions, while respecting the common desire to preserve classroom instructional time

Multiple–True–False Questions Reveal the Limits of the Multiple–Choice Format for Detecting Students with Incomplete Understandings

By having students select one answer among several plausible options, multiple–choice (MC) questions capture a student’s preferred answer but provide little information regarding a student’s thinking on the remaining options. We conducted a crossover design experiment in which similar groups of introductory biology students were assigned verbatim questions in the MC format or multiple–true–false (MTF) format, which requires students to separately evaluate each option as either true or false. Our data reveal that nearly half of the students who select the correct MC answer likely hold incorrect understandings of the other options and that the selection rates for individual MC options provide inaccurate estimations of how many students separately endorse each option. These results suggest that MC questions systematically overestimate question mastery and underestimate the prevalence of mixed and partial conceptions, whereas MTF questions enable students and instructors to gain a more nuanced portrait of student thinking with little additional effort

Knowing your own: A classroom case study using the scientific method to investigate how birds learn to recognize their offspring

Understanding the scientific method provides students with a necessary foundation for careers in science-related fields. Moreover, students can apply scientific inquiry skills in many aspects of their daily lives and decision making. Thus, the ability to apply the scientific method represents an essential skill that students should learn during undergraduate science education. We designed an interrupted case study in which students learn about and apply the scientific method to investigate and recapitulate the findings of a published research article. This research article addresses the question of how parents recognize their own young in a system where birds of the same species lay eggs in each other’s nests. The researchers approach the question through three experiments in which the bird’s own offspring and unrelated offspring hatch in different orders. This experiment specifically tests for the effect of hatching order on the bird’s ability to recognize its own offspring. In the case study, students form hypotheses based on behavioral observations made while watching a video clip, together with background information provided by the instructor. With additional information about the experimental design, students make graphical predictions for the three related experiments, compare their predictions to the results, and draw conclusions based on evidence. This lesson is designed for introductory undergraduate students, and we provide suggestions on how to adjust the lesson for more advanced students. This case study helps students differentiate between hypotheses and predictions, introduces them to constructing and interpreting graphs, and provides a clear example of the scientific method in action

Positive Carotenoid Balance Correlates with Greater Reproductive Performance in a Wild Bird

Background: Carotenoids can confer somatic and reproductive benefits, but most evidence is from captive animal experimentation or single time-point sampling. Another perhaps more informative means by which to assess physiological contributions to animal performance is by tracking an individual’s ability to increase or sustain carotenoids or other health-related molecules over time, as these are likely to be temporally variable. Methodology/Principal Findings: In a field study of North American barn swallows (Hirundo rustica erythrogaster), we analyzed within-individual changes in carotenoid concentrations by repeatedly sampling the carotenoid profiles of individuals over the course of the breeding season. Our results demonstrate that carotenoid concentrations of individuals are temporally dynamic and that season-long balance of these molecules, rather than single time-point samples, predict reproductive performance. This was true even when controlling for two important variables associated with reproductive outcomes: (1) timing of breeding and (2) sexually selected plumage coloration, which is itself positively correlated with and concomitantly changes with circulating carotenoid concentrations. Conclusions/Significance: While reproduction itself is purported to impose health stress on organisms, these data suggest that free-ranging, high-quality individuals can mitigate such costs, by one or several genetic, environmental (diet), or physiological mechanisms. Moreover, the temporal variations in both health-linked physiological measures and morphological traits we uncover here merit further examination in other species, especially when goals include the estimation of signal information content or the costs of trait expression

Multimodal signalling in the North American barn swallow: a phenotype network approach

Complex signals, involving multiple components within and across modal- ities, are common in animal communication. However, decomposing complex signals into traits and their interactions remains a fundamental challenge for studies of phenotype evolution. We apply a novel phenotype network approach for studying complex signal evolution in the North American barn swallow (Hirundo rustica erythrogaster). We integrate model testing with correlation-based phenotype networks to infer the contributions of female mate choice and male–male competition to the evolution of barn swallow communication. Overall, the best predictors of mate choice were distinct from those for competition, while moderate functional overlap suggests males and females use some of the same traits to assess potential mates and rivals. We interpret model results in the context of a network of traits, and suggest this approach allows researchers a more nuanced view of trait clustering patterns that informs new hypotheses about the evolution of communication systems. 3 supplemental files attached below

The importance of cross-validation, accuracy, and precision for measuring plumage color: A comment on Vaquero-Alba et al. (2016)

Vaquero-Alba and colleagues published a study in The Auk: Ornithological Advances comparing objective color measurements of plumage taken in the field directly on a bird’s body to those taken in the lab on collected feathers arranged to emulate the appearance of a bird’s natural plumage. Although the field measures of plumage color were less repeatable than lab measures, the authors concluded that measurements taken in the field were more representative of a bird’s ‘‘true color.’’ Accordingly, they recommend that researchers should bring spectrophotometers into the field to measure color on live birds. We question the assumption that their field measurements represent true color and highlight concerns regarding their experimental design and methodology. Because they did not measure color of live birds in the lab or the color of plucked feathers in the field, they cannot directly test whether the assessment of color in the field on a live bird is superior. Also, rather than assume field measures are the most accurate or precise way to assess plumage color, we suggest cross-validation with other methodologies, such as digital photography, pigment biochemistry, or measures of a known color standard in both environments. Importantly, researchers should be aware of the limitations and advantages of various methods for measuring plumage color so they can use the method most appropriate for their study. Vaquero-Alba y sus colaboradores publicaron un estudio en The Auk comparando medidas objetivas del color del plumaje tomadas en el campo directamente en el cuerpo del ave con medidas tomadas en el laboratorio en plumas recolectadas y organizadas para emular la apariencia natural del plumaje. Aunque las medidas de campo del color del plumaje fueron menos repetibles que las de laboratorio, los autores concluyeron que las medidas tomadas en el campo fueron ma´s representativas del ‘‘color verdadero’’ de un ave. En consecuencia, recomendaron que los investigadores deben llevar espectrofot ´ ometros a los sitios de campo para medir el color en aves vivas. Cuestionamos la suposici ´on de que sus mediciones de campo representan el ‘‘color verdadero’’ y resaltamos nuestras preocupaciones con respecto a su dise ˜no experimental y metodolog´ıa. Debido a que ellos no midieron el color de las aves vivas en el laboratorio ni el color de las plumas sueltas en el campo, no pueden evaluar directamente si la evaluaci ´on del color en el campo en un ave viva es superior. Tambi´en, en vez de asumir que las medidas de campo son la forma ma´s exacta o precisa de determinar el color del plumaje, sugerimos que se haga una validaci ´on cruzada con otras metodolog´ıas como la fotograf´ıa digital, la bioqu´ımica de los pigmentos o las medidas de un esta´ndar de un color conocido en ambos ambientes. Es importante que los investigadores tengan en cuenta las limitaciones y avances en varios m´etodos para medir el color del plumaje para que puedan usar el m´etodo ma´s apropiado para su estudio

The importance of cross-validation, accuracy, and precision for measuring plumage color: A comment on Vaquero-Alba et al. (2016)

Vaquero-Alba and colleagues published a study in The Auk: Ornithological Advances comparing objective color measurements of plumage taken in the field directly on a bird’s body to those taken in the lab on collected feathers arranged to emulate the appearance of a bird’s natural plumage. Although the field measures of plumage color were less repeatable than lab measures, the authors concluded that measurements taken in the field were more representative of a bird’s ‘‘true color.’’ Accordingly, they recommend that researchers should bring spectrophotometers into the field to measure color on live birds. We question the assumption that their field measurements represent true color and highlight concerns regarding their experimental design and methodology. Because they did not measure color of live birds in the lab or the color of plucked feathers in the field, they cannot directly test whether the assessment of color in the field on a live bird is superior. Also, rather than assume field measures are the most accurate or precise way to assess plumage color, we suggest cross-validation with other methodologies, such as digital photography, pigment biochemistry, or measures of a known color standard in both environments. Importantly, researchers should be aware of the limitations and advantages of various methods for measuring plumage color so they can use the method most appropriate for their study. Vaquero-Alba y sus colaboradores publicaron un estudio en The Auk comparando medidas objetivas del color del plumaje tomadas en el campo directamente en el cuerpo del ave con medidas tomadas en el laboratorio en plumas recolectadas y organizadas para emular la apariencia natural del plumaje. Aunque las medidas de campo del color del plumaje fueron menos repetibles que las de laboratorio, los autores concluyeron que las medidas tomadas en el campo fueron ma´s representativas del ‘‘color verdadero’’ de un ave. En consecuencia, recomendaron que los investigadores deben llevar espectrofot ´ ometros a los sitios de campo para medir el color en aves vivas. Cuestionamos la suposici ´on de que sus mediciones de campo representan el ‘‘color verdadero’’ y resaltamos nuestras preocupaciones con respecto a su dise ˜no experimental y metodolog´ıa. Debido a que ellos no midieron el color de las aves vivas en el laboratorio ni el color de las plumas sueltas en el campo, no pueden evaluar directamente si la evaluaci ´on del color en el campo en un ave viva es superior. Tambi´en, en vez de asumir que las medidas de campo son la forma ma´s exacta o precisa de determinar el color del plumaje, sugerimos que se haga una validaci ´on cruzada con otras metodolog´ıas como la fotograf´ıa digital, la bioqu´ımica de los pigmentos o las medidas de un esta´ndar de un color conocido en ambos ambientes. Es importante que los investigadores tengan en cuenta las limitaciones y avances en varios m´etodos para medir el color del plumaje para que puedan usar el m´etodo ma´s apropiado para su estudio

Positive Carotenoid Balance Correlates with Greater Reproductive Performance in a Wild Bird

Background: Carotenoids can confer somatic and reproductive benefits, but most evidence is from captive animal experimentation or single time-point sampling. Another perhaps more informative means by which to assess physiological contributions to animal performance is by tracking an individual’s ability to increase or sustain carotenoids or other healthrelated molecules over time, as these are likely to be temporally variable. Methodology/Principal Findings: In a field study of North American barn swallows (Hirundo rustica erythrogaster), we analyzed within-individual changes in carotenoid concentrations by repeatedly sampling the carotenoid profiles of individuals over the course of the breeding season. Our results demonstrate that carotenoid concentrations of individuals are temporally dynamic and that season-long balance of these molecules, rather than single time-point samples, predict reproductive performance. This was true even when controlling for two important variables associated with reproductive outcomes: (1) timing of breeding and (2) sexually selected plumage coloration, which is itself positively correlated with and concomitantly changes with circulating carotenoid concentrations. Conclusions/Significance: While reproduction itself is purported to impose health stress on organisms, these data suggest that free-ranging, high-quality individuals can mitigate such costs, by one or several genetic, environmental (diet), or physiological mechanisms. Moreover, the temporal variations in both health-linked physiological measures an