VictorJuiz/thesis huggingface dataset:
What counts as science writing and who gets to be "good" at it? : pedagogy, ideology, and inequality in high school biology
Keywords: Education.

Writing matters in science education. It can provide opportunities not only for assessment or developing writing skills, but also for learning content and developing students' identities as producers of scientific knowledge. New research and educational standards suggest these goals can be achieved through a variety of activities, including writing activities with real-world audiences and few linguistic constraints. However, history also suggests that pedagogical reforms can have unintended consequences, and that systemic racism and sexism can shape the outcomes of reforms in unanticipated and inequitable ways. To provide all students with equitable opportunities to learn science through writing, researchers must proactively investigate problems that may arise during the implementation of new writing activities. This dissertation uses survey and experimental methods to examine how teachers of biology (the most common science course in U.S. secondary schools) implement, evaluate, provide feedback on, and formulate expectations for student writing. Findings suggest: (1) participants' stated purposes for student writing do not always align with enacted writing pedagogy; (2) participants provided longer feedback on student writing attributed to a non-Hispanic White male compared with the same writing attributed to Hispanic or Latina female; and (3) participants who worked in schools that served primarily White and Asian American students expressed higher expectations for student science writing than colleagues in schools serving primarily Latinx or African American students. Practical and theoretical implications for science educators, researchers, and policymakers are discussed.
When do gradient methods work well in non-convex learning problems?
Keywords: Statistics.

Classical learning theory advocates the use of convex losses in machine learning due to its guaranteed computational efficiency, yet recent success in deep learning suggests that highly non-convex losses can often be efficiently minimized by simple gradient-based algorithms, a phenomenon not well explained by existing theory. Towards closing this gap, this thesis proposes and instantiates landscape analyses, a theoretical framework for studying the optimization of non-convex learning problems via analyzing optimization-aware geometric properties of the empirical risk. In the first part of the thesis, we establish a generic connection between the optimization landscape of smooth non-convex empirical risks, namely, that their gradients and Hessians concentrate uniformly around those of the population risk with statistical rate. Consequently, benign landscape properties on the population risk can be carried onto the empirical risk as well when the sample size is sufficiently large. We apply this principle to showing that gradient descent succeeds in solving several non-convex empirical risk minimization problems, including non-convex binary classification (and its sparse version), robust linear regression, and Gaussian mixture estimation. In the second part, we adopt landscape analysis to solving the orthogonal dictionary learning problem via minimizing a non-convex non-smooth L1 risk on the sphere, which was shown to work well empirically but not well understood in theory. Standard uniform convergence analysis fails on this problem as the subgradients are set-valued and non-Lipschitz. We develop tools, building on Hausdorff distance between sets and a novel sign-aware metric customized for the dictionary learning problem, to handle the above issues and establish the uniform convergence of subgradients. We show that the landscape of the non-smooth empirical risk is benign and subgradient descent succeeds in recovering the dictionary with required sample complexity lower than existing approaches based on non-convex optimization
When people's voices matter : examining mini-public deliberation and digital crowdsourcing with machine learning tools
Keywords: Communication.

Governments across the world have been increasingly using a variety of forms of public consultation to inform governance and strengthen legitimacy. In some public consultation, people's voices are thoughtful and consequential for policymaking while in other forms of public consultation, people's voices are more likely to be distorted by political interests. This dissertation aims to answer a question (challenge) posed by the latest development in the field deliberative democracy: what institutional designs can make a deliberative system function well and/or badly? To answer this question, I examine in depth, cases of mini-public deliberation and digital crowdsourcing. My dissertation provides building blocks regarding the elements of design for an effective deliberative system and offers suggestive lessons for facilitating a healthier and more impactful public dialogues in both democracies and authoritarianisms. My dissertation also demonstrates how we could leverage machine learning tools to systematically analyze the impact and quality of political dialogues.
Wishful thinking, wishful seeing: The effects of arousal on motivated perception
Keywords:  Symbolic Systems Program
department of psychology
social neuroscience lab
affective neuroscience
motivated perception
arousal
perceptual bias
visual perception
Thesis

Desires and wants can bias perception, making people see what they want to see. However, little is known about the psychological mechanisms that give rise to this bias. In this study, we investigated if motivational influences on visual perception are associated with changes in levels of physiological arousal. Specifically, we predicted that arousal mediates the effects of motivation (i.e. wanting to see) on perception (i.e. seeing). Participants were presented with ambiguous composite images created by morphing a face image and a scene image together, and were rewarded for correctly categorizing whether the face or scene image was of higher intensity. We motivated them to want to see one category over another by telling them they would win a bonus if the image was of a particular category. Pupil dilation was used as a proxy measure of arousal. Replicating previous findings, individuals were more likely to make motivationally consistent choices in perceptually ambiguous scenarios. Results from the pupil responses to the task suggest that an increase in individual bias is associated with stronger pupil response in some motivated contexts. In Experiment 1, subjects with higher levels of bias displayed stronger arousal responses in all motivated contexts. In Experiment 2, subjects with higher levels of bias displayed stronger arousal responses only during motivationally consistent trials. In both studies, we found that subjects with higher levels of motivational bias tended to have larger differences in pupil response between motivationally consistent and unmotivated contexts. Overall, our results demonstrate that arousal, as measured by pupil response, was positively associated with motivated perception, and contributes to our understanding of the physiological factors affecting biased perceptual judgments.
Wolfgang: Helping novice music learners feel musical
Keywords: music
middle school
self-efficacy
tension
embodied
playful
Thesis

Middle school novice music learners with some basic experience need to feel that music is for them, they are musical and they can do music too if they put in the effort because music makes us more human. Living in a world filled with music, humans have naturally developed implicit knowledge about music. Without us realizing how it works, the tension and resolution in our favorite songs elicit an array of emotions that move us. Unfortunately, middle school students often don’t realize how much they already know about music and give up music at a stage critical for their aesthetics and identity development because they don’t feel “musical” enough and because what they are interested in learning isn’t what is being taught. Wolfgang is an expressive musical toy that allows novice music learners to play the chords of their favorite songs by manipulating the musical tension through physical exertion, thereby creating an embodied and playful music making experience. Learners were able to perform short sequences of chords in user tests, although more rigorous studies are required to investigate other learning outcomes such as self-efficacy.
The work of teams and the careers of individuals : performance and mobility in interdependent work settings
Keywords: Business.

This dissertation is about the career and work consequences of team based labor. As economic and labor surveys have shown for many years, more and more people do their work in teams, and it is the team that is often seen as the fundamental work unit, rather than the individual. This has two consequences. The first is that team choice and team structure have consequences for individual careers. For example, a team that works well together may give its members more opportunities for individual advancement that stall without their teammates present. Second, the career choices of individuals have lasting effects on teams themselves. For example, varying rates of mobility between teams affects team stability and norms, and these mobility patterns are a consequence of an individual's career opportunities. Thus, we should expect greater co-evolution of team and career dynamics within internal and open labor markets. Depending on the context for work and reward, the relationship between the two may be hostile, mutually beneficial, and the variations in between. The studies of this dissertation examine different elements of this relationship. Chapter 1 studies the effect that inter-team mobility has on performance (more is better), chapter 2 examines the consequences of one's collaboration history and future success (it depends on how you're paid), while chapter 3 asks whether people's own recognition of these dynamics helps them do better in their career planning (you get paid more if you think about people besides yourself). It closes with some thoughts on future inquiry into this topic.
Workplace participation, empowerment, and social dynamics
Keywords: Sociology.

This dissertation is to explore workplace dynamics in a modern corporation and their implications. I follow economic sociologists to envision a firm as an organization embedded in social structure, and present empirical findings and theoretical explanations about workplace participation, empowerment, and social dynamics. First, I analyze workplace engagement policies, programs, and practices and their implications for organizational dynamics. More specifically, I suggest that empowering workers with rights to ownership, returns, and decision-making supports stability and robustness of organizational social structure, or ongoing social relations within an organization. Such empowerment enhances organizational trust, which in turn promotes organizational outcomes in workplace commitment and satisfaction. Second, I study whether such workplace dynamics have any spillover effects beyond organizations. I show that workplace empowerment enhances participation in voluntary associations, which in turn promotes political participation in the public sphere. Third, I take a look at a worker co-op, or a democratic workplace collectively owned and run by workers. I present an in-depth ethnographic study of a worker co-op, analyzing its organizational emergence and dynamics. Overall, this dissertation aims to contribute to the tradition of economic sociology and organization studies by examining and exploring the social dynamics of an alternative model of capitalism in our era.
World knowledge, context and structure : the use and acquisition of dimensional adjectives
Keywords: Linguistics.

The interpretation of words in natural language is partially determined by the context in which they are used. Context can refer both to the immediate physical context and to the world knowledge of the speakers. It is known that both of these aspects of context play a role in language interpretation, but the contribution of each aspect, how the two aspects interact with each other and what constitutes world knowledge are open questions. The main goal of this dissertation is to examine these three questions. I focus on relative adjectives, such as 'big' and 'small', whose meaning is typically evaluated relative to a contextually determined ``comparison class''. Their explicit context sensitivity makes these adjectives a good test case examining the role of context in language interpretation. To accomplish this goal, I present a series of experiments aimed at showing the interaction of the immediate visual context and world knowledge in the interpretation of relative adjectives, as well as the interplay between different types of world knowledge in this process. The data from these experiments show that world knowledge is integrated with information from the immediate visual context and that at least two different types of world knowledge are involved. I argue that manipulating the stimuli present in the visual context affects the interpretation of the adjectives by shifting the salience of the two types and thus shifting the comparison class relative to which the adjectives are interpreted. The secondary goal of this dissertation is to examine the role context plays in the acquisition of relative adjectives, focusing on a particular subset: dimensional adjectives, such as 'big', 'tall' and 'wide'. To address this question, I present an elicitation study of dimensional adjective antonyms. Dimensional adjectives all designate the physical extent of an object; each specifies a particular dimension (e.g., verticality for 'tall') and polarity. Finally, each is associated with an antonym of opposing polarity; forming this association requires understanding the contribution of all of the adjectives' meaning components. Therefore, studies of antonym acquisition can provide a window into the structure of the semantic field. Through an experiment designed to elicit dimensional antonyms from Hebrew speaking children using pictures for contextual support, I show that context helps anchor children's association of one member of an antonym pair with the other. Their responses reflect the stages of acquisition of dimensional adjectives demonstrating progressive and structured knowledge of these meaning components. Together, the two investigations in this dissertation provide new insight from multiple perspectives on the interaction of context, world knowledge and language.
3- and 4-year-olds’ Comprehension of Polite Requests
Keywords:  Department of Symbolic Systems
politeness
speech comprehension
language development
Symbolic Systems
Thesis

Politeness is one of the essential components of being able to communicate in a social world, but not much is known about how or when politeness is understood by very young children. Thus, this paper examines 3- and 4-year-olds’ judgements on simple requests. More specifically: When do children begin to grasp the basics of politeness? Are some forms of requests easier to judge as more polite than others? Do young children understand both what it means to be “polite” and “rude”? To answer these questions, 3- and 4-year-olds were presented with an iPad game containing several stories which asked the participants to choose the more polite or more rude request out of two options. The audio for each utterance was pre-recorded and all utterances were recorded with a rising intonation at the end (like a question) in order to standardize the input across all participants. The results showed that there was a difference in performance between the 3- and 4-year-old participants, with 3-year-olds performing at around chance or just above when judging which request was more polite or rude and 4-year-olds answering correctly about 80% of the time. Furthermore, there was no significant difference in performance depending on the form of the more polite request nor when the participants were asked to pick the “more rude” utterance as compared to when asked to choose the “more polite” one. Thus, it seems that at least by the age of four, children begin to understand which requests are more polite and which ones are more rude.
A Break in the Cloud: Finding the Local in the Global Internet
Keywords: Computer Science
STS
Interdisciplinary Honors
Internet
Media Studies
Cloud Computing
Media Infrastructure
Community
Access
Digital Divide
Thesis

The Internet has radically changed every mode of production, distribution, and consumption in modern life, granting global access to information transcending time and space. However, the physical infrastructure that enables the Internet is often overlooked, due to the virtual and intangible nature of Internet connection. This disconnect between the digital and the physical is captured by the popular buzzword - “the cloud” - a metaphor that abstracts away the vast, energy-guzzling tracts of data server farms kept hidden in corporate secrecy. This thesis seeks to make “the cloud” visible and concrete, and in doing so, zooms in from the Internet’s “global village”1 back to the physical realities of Internet infrastructure embedded within local communities. Through an analysis and synthesis of technical papers, corporate marketing, policy reports, and maps, it situates the “global” nature of the cloud within national and local politics and communities. In addition, through a case study of Google’s first data center in The Dalles, Oregon, and its intimate relationship with a community-piloted municipal fiber network - QLife Network - this thesis brings local community needs and negotiations in conversation with the global corporate order of digital technologies. The discussion concludes with a proposed framework for a community-oriented approach to accessing the global Internet, urging for visibility through new media art and community-based Internet infrastructure investment. Recognizing the realities of local within a global Internet makes the first necessary step in bringing the cloud out of its technological black box, and in short, finding the break in the cloud.
A Cost-Benefit Analysis of the Electrification of Rural India from 2005 to 2012
Keywords: rural electrification
India
developing countries
income
kerosene
cost-benefit
Stanford University
Department of Economics
Thesis

Electricity has been a key characteristic of modern society and has been a catalyst for economic development. Over the last twenty years, India has electrified 350 million people, yet 30% of rural populations still have no electricity. Using a probit model, I calculate the drivers that impact electricity adoption. I then use a difference-in-differences technique to measure the benefits of having electricity. Finally, I compare the benefits of electrification to the cost of purchasing electricity every year. The probit model shows that income and education are positively correlated with the probability of purchasing electricity. Households who do electrify exhibit single digit gains to income and expenditure, and increased adoption of fans and televisions. Kerosene use also decreases. In conclusion, the cost of having electricity is found to be larger than the income gain for 25% of the population, nevertheless, the welfare gains provide sufficient reason for the promotion of electricity in rural India.
A Dynamic Global Invader: A Genetic Analysis of Aedes albopictus in Costa Rica
Keywords:  Department of Biology
Biology
Aedes albopictus
Population genetics
Costa Rica
phylogeny
Thesis

The mosquito Aedes albopictus, originating from southeast Asia, has expanded throughout the world during the 20th century, adapting to a variety of different regions and habitats and spreading diseases such as dengue, chikungunya, and Zika. Within these invasive populations little is known about the genetic diversity and population structure, particularly in Central America. Previous studies on the diversity of Ae. albopictus have been performed in countries such as the United States and Malaysia; however, few studies have examined population structure, genetic diversity, and phylogenetic relationship of Ae. albopictus populations in Central America, where dengue and other viruses are actively spreading. Understanding these important genetic markers and relationships will guide future research to allow for more direct targeting of vector control efforts. Ae. albopictus were captured using five different trapping methods in locations covering a wide range of land uses and temperatures across southern Costa Rica. We assessed population genetic structure by sequencing the mitochondrial Cytochrome C Oxidase 1 (CO1) gene. A phylogenetic tree constructed from our Costa Rican sequences and other world population sequences revealed a slight clustering of the Costa Rican population with populations from temperate regions. Examination of our sequences also revealed little population structuring, which indicates that the geographically separated populations are still intermixing despite the barriers that exist. Understanding the genetics of the Ae. albopictus within Costa Rica will be fundamental to future research to determine how the species will respond to the anthropogenic changes in temperature and land use in southern in Costa Rica. This in turn could aid in proactive mosquito control and public health management to reduce the incidence of the mosquito-borne viral infections.
A forward genetic screen identifies new host factors influencing bacteriophage lambda's lysis-lysogeny decision
Keywords:  Department of Bioengineering
Bioengineering
Stanford
School of Engineering
systems biology
bacteriophage lambda
genetic screen
Thesis

In order to survive, organisms must integrate internal and external signals via complex signaling pathways to intelligently navigate their environment. Bacteriophage lambda has long been a classic model for understanding such pathways, and how they allow cells to effect changes in physiology in order to adapt to varying circumstances. When infecting its host Escherichia coli, phage lambda may either make more viruses (lysis), or integrate itself into the host genome (lysogeny). To better understand the extent to which host physiology influences the lysis-lysogeny decision, I performed a forward genetic screen to identify genes whose deletions bias the infected cell towards lysis or lysogeny. This screen revealed numerous host-encoded genes linked to the lysis-lysogeny decision, including transcription factors and genes in metabolic pathways. These results demonstrate previously unknown links between host physiology and viral decision-making, shedding new light on this classic model system.