Browsing by Author "Lane, David"

Now showing 1 - 7 of 7
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    Efficacy of MedMyst: an Internet Teaching Tool for Middle School Microbiology
    (2004-05) Miller, Leslie M.; Moreno, Janette; Estrera, Vicky; Lane, David; National Institutes of Health, National Center for Research Resources; Center for Technology in Teaching and Learning; American Society for Microbiology
    Can web-based technology be used to effectively introduce or reinforce aspects of microbiology to middle school students? This central hypothesis examines whether brief exposure to a web adventure format containing virtual lab experiments and computer games within an engaging story line can impact student learning. An episodic adventure series, MedMyst (http://medmyst.rice.edu), focuses on infectious diseases and the microbes that cause them. The website is not intended to replace classroom instruction, but rather to engage students in problem-solving activities not likely to be encountered elsewhere. It also provides scientists with a resource to introduce microbiology to adolescent audiences through outreach activities. In the online adventure, the player (student) enters a futuristic world in which he or she becomes a “Reconstructor,” a member of an elite team charged with preventing the spread of infectious disease. The series consists of three “missions,” each lasting approximately 30 to 40 minutes and designed to address a limited set of learning objectives. Middle school students participated in the creation of the characters and the stylized design through focus groups. Classroom teachers oversaw the alignment of the web adventure objectives with the National Science Content Standards. Scientists and clinicians reviewed the web adventure for content and accuracy. A field test involving over 700 students from nine different schools assessed the knowledge gains attributable to playing MedMyst. Gain scores from pretest to posttest indicated that middle school students retained important information by interacting with the online material for as little as 30 minutes per adventure; however, gains for high school students were less persuasive, perhaps indicating a different learning tool or content is required for this age audience.
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    Intraspecific variation in metacommunities: Linking regional heterogeneity to local population dynamics
    (2014-12-03) Dibble, Christopher Joseph; Rudolf, Volker H. W.; Miller, Tom; Kohn, Michael; Lane, David
    Variation within species drives differences in population dynamics, interactions between species, and the functioning of complex ecosystems. Fittingly, understanding the factors that govern this intraspecific variation remains a central goal of ecology and evolutionary biology. Local processes such as adaptation tend to increase divergence among distinct populations, while regional processes such as dispersal and gene flow tend to homogenize those differences. My research addresses how heterogeneity is maintained despite the movement of individuals around a landscape. Specifically, I use an experimental host-parasite system to propose and test mechanisms contributing to ecological differentiation. Initially, I found that variation in colonizer traits makes the order in which they arrive to a new habitat important. Intraspecific priority effects (IPEs) occur when early arrivers limit the growth of late arrivers, and drive context-dependent differences in growth among populations (Chapter 1). These effects of variation in individual traits and arrival order extended to alter interspecific competition and host/parasite interactions. My research indicates, then, that the process of community assembly depends not only on the traits of a dominant species in the environment, but also which individuals of that species get there first (Chapter 2). The relatively short-term importance of IPEs, however, may wane over time as individuals continue to disperse among populations. I tested the consequences of repeated dispersal, and found that they depend heavily on the expected fitness of migrants in their new habitat. That is, dispersal from a common source can increase ecological heterogeneity among populations if migrants have different effects in different environments (Chapter 3). The context-dependent effects of dispersal suggested an underlying trait-based mechanism. Specifically, I hypothesized that the effects of increasing trait variance in a population (e.g. via immigration) depend on the relationship between a population’s trait mean and the local environmental optimum. I found that increasing trait variance helps populations with suboptimal trait means, but harms populations already well-suited to the local environment, doubling their disease burden (Chapter 4). Overall, my research identifies novel ways in which intraspecific variation contributes to its own maintenance, limiting the ability of individual movement among populations to homogenize ecological and evolutionary differentiation.
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    Male Allies: Men Convince other Men that Gender Equity Matters
    (2017-05-26) Trump, Rachel Christina Elizabeth; Hebl, Mikki; Lane, David
    Despite decades of improvement, women still face disparities in the workplace relative to men (Lyness & Heilman, 2006). In a total of four studies, I examined how men can play an important role in getting other men to endorse gender-equitable attitudes and behaviors. In Study 1, men and women read articles related to gender that have either male or female authors. The results of this study show that male respondents react more positively when the article is written by a man; however female respondents reacted similarly to both male and female authors. In Study 2, male and female sellers sold cookies for and asked for donations to support a women’s resource center, and asked customers to fill out a survey of their attitudes towards gender equity. The results of this study revealed that male customers bought more cookies and donated more money to male sellers. In Study 3, men read articles authored by men or women, and that used one of five different persuasion strategies. Results revealed that men endorsed more support for gender equity when the author was male. Also, the strategy of “highlighting male role models who support women” was the most successful strategy for persuading both men and women. In Study 4, male and female sellers sold restaurant cards to support a women’s organization using either no strategy, or highlighting male role models. Although there were no gender differences in the amount who purchased restaurant cards (less than 3% of those asked actually purchased cards), male (versus female) sellers indicted more positive feedback from potential male customers. As a whole, this research suggests that men may be more effective at getting other men to embrace gender equitable beliefs than women.
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    Robust Methods for Forecast Aggregation
    (2014-08-18) Ramos, Jaime J; Scott, David W.; Lane, David; Thompson, James R
    This study introduces a new forecast aggregation technique. Adding to the well- known difficulties and uncertainty involved in the forecasting process, the aggregation of hundreds or thousands of forecasters’ opinions and expert predictions on social, economical and political matters makes the process even more difficult. Simple quan- titative data analytics, least squares regression, and maximum likelihood estimations are not sufficient to handle the dynamics of such data, which includes outliers, clusters of opinions, extreme values, and abrupt change of mind and predictions of forecasters influenced by news, recent events, collaboration or feedback from experts. The meth- ods developed in this work are based on a particular minimum-distance technique called L2E, which is popular in nonparametric density estimation that makes the aggregation robust to clusters of opinions and dramatic changes. Variance-stabilizing transformations are introduced to attain homoscedasticity for L2E regression improv- ing parameter estimation and overall aggregation. New normalization approaches are proposed to use when the aggregated values are unsuitable probabilities, such as values ∈/ [0, 1] and/or do not add to 1. Finally, data visualization techniques and graphical user interfaces (GUIs) are discussed as aid to decision makers in order to understand “single” aggregated forecast values, obtained from the original big data set analyzed, and the trend of such aggregated forecasts over the forecasting period.
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    Statistically Adrift: Why A Central Conclusion in Academically Adrift is Faulty
    (2012) Lane, David; Oswald, Fred; Department of Psychology
    One of the most cited findings reported in the book Academically Adrift: Limited Learning on College Campuses by Arum and Roska is that 45 percent of the students did not show a statistically significant gain in critical thinking. In this paper we show that the significance tests were conducted incorrectly and that it would be very unlikely for any single student to show a statistically significant gain.
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    System Usability and User Mental Models of Three Verifiable, End-to-end Voting Methods: Helios, Prêt à Voter, and Scantegrity II
    (2014-07-11) Acemyan, Claudia Ziegler; Kortum, Philip T; Byrne, Michael D; Lane, David; Wallach, Dan S.
    There are many ways voting systems can be maliciously attacked so that election outcomes are altered. In response, voting security experts developed end-to-end (e2e), verifiable voting methods. These systems were intended to be secure, accurate, reliable, and transparent, while still preserving voter anonymity. What is not clear is if these complex, novel systems, which allow voters to check on their ballots after voting, will be usable by every voter. If voting methods are unusable, negative ramifications like disenfranchisement and altered election outcomes could occur. For this reason, system usability and voter mental models of e2e systems must be understood. To address this lacuna in voting research, three e2e methods representative of voter verifiable technologies were studied: Helios, Prêt à Voter, and Scantegrity II. Four studies were conducted. In the first study, baseline usability data was collected. By having participants vote with each system in a mock election, it was found that the systems were difficult, if not impossible, to use. Only 58% of voters were able to cast a ballot, and fewer were able to verify their vote. In the second study, the behavioral errors that led to ballot casting and vote verification event failures were identified, and potential contributing system design deficiencies were discussed. This study revealed that a few design details were driving most of the observed failures, of which all can be fixed. In the third study, voters’ mental models for each voting system were explored. The data supported the claim that voters did not have comprehensive mental models accounting for how the systems work; rather their models emphasized how-to-vote procedures, which were not always correct. In the fourth study it was asked if voters even wanted to use the verification systems, and if they did, what form of verification they would expect. Sixty-five percent of voters indicated that they would be interested in checking that their ballot was cast. As for the preferred form of verification, there was not a consensus—indicating that a diverse set of expectations will need to be accounted for when developing the systems. In conclusion, the tested e2e systems were not easily usable by voters, fully understood by them, or in a form that voters might have expected. Yet the system problems observed can be fixed, and voters seem to support the idea of auditable voting systems—meaning future effort should be spent improving upon the next generations of e2e systems so that all voters can use secure, accurate, transparent, and reliable voting systems.
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    The role of working memory in interference resolution during Chinese sentence comprehension: Evidence from event-related potentials (ERPs)
    (2015-09-24) Tan, Yingying; Martin, Randi C.; Lane, David; Fischer-Baum, Simon; Shibatani, Matt
    Interference during sentence comprehension occurs when readers use semantic and syntactic cues to retrieve earlier sentence information to integrate with later information and intervening material partially matches these cues, resulting in more parsing difficulty. This thesis collected event-related brain potentials (ERPs) while participants processed Chinese sentences with semantic and syntactic interference to address two main questions: 1) When do semantic and syntactic interference effects occur and do they interact with each other? 2) What is the role of working memory (WM) mechanisms in interference resolution? Semantic and syntactic interference were examined during processing of the critical main clause verb (e.g., “complain”) that required the retrieval of a human subject noun. The degree of semantic interference was manipulated through varying the semantic plausibility of a distracting noun (e.g., human vs. non-human), and syntactic interference was manipulated through varying the distracting noun’s grammatical role in the relative clause (i.e., subject vs. object). Individual differences measures were collected on aspects of working memory, executive function, and verbal knowledge. Regarding the timing of interference effects, the ERP results at the critical verb showed negative anterior effects between 300 – 500 ms for both syntactic and semantic interference. Syntactic interference also induced a P600 effect and semantic interference also induced a late left anterior negativity. I interpret the early anterior negativities as reflecting a first stage process of detecting the semantic or syntactic interference, and the late ERPs as reflecting a second stage of reanalysis/revision during sentence processing. Importantly, the current results demonstrated that semantic processing plays an immediate and important role in Chinese, because the semantic interference effect was observed as early as the syntactic interference effect even when the distracting noun’s syntactic features strongly eliminated it from the distractor set. In contrast, semantic interference has been shown to be delayed and even blocked in previous English studies using similar materials. Regarding the role of WM in interference resolution, the present study supports a role of attentional control underlying sentence comprehension. Subjects with better resistance to proactive interference, as measured by a recent negatives task, had less difficulty in syntactic interference resolution, as indexed by a reduced mean amplitude of the P600 effect elicited by the high syntactic interference condition, even after controlling for their verbal knowledge and general processing speed. This result is consistent with the argument that attentional control helps subjects to recover from interference during later controlled aspects of sentence processing.