Eliciting Bootstrapping: The Development of Introductory Statistics Students’ Informal Inferential Reasoning via Resampling

Bootstrapping has become an important tool for statisticians, who assert that it is intuitive to novice statistics students. The process of collecting bootstrap resamples was once time demanding, but technology now allows data collection to be performed nearly instantaneously. This study focuses on the construction and development of secondary and tertiary introductory statistics students\u27 (n=68) reasoning about bootstrapping and informal inference. Students engaged in a four-week instructional unit designed as two model development sequences. Through the use of hands-on manipulatives and technology, students constructed and developed reasoning of sampling, the resampling process of bootstrapping, and inference. The focus of my analysis was on the model development of four focus groups of students. Groups of students constructed models of sampling and inference that they used to collect samples, aggregate the samples to form an empirical sampling distribution, and use the aspects of this distribution of samples to make claims about the population from which the samples were drawn. I summarize and categorize groups of students’ models and trace the development of the focus groups’ models throughout the unit. Simulation of data led some students to develop a global view of the randomness of sampling and reason with multiple aspects of empirical sampling distributions to draw inferential claims. Some students applied a multiplicative view of the sample and global view of the sampling process to construct a resampling process similar to bootstrapping, but fell short of constructing the bootstrapping process by not collecting resamples that were equal in size to the original sample. Class discussion of a follow-up activity, similar in structure to the model eliciting activity, encouraged students to consider the value of drawing resamples of equal size to the population and led students to construct the method of bootstrapping. Students then used the bootstrapping process to drawn inferences about one population and to compare two populations of data. The findings of this study contribute to the field of statistics education by examining student thinking while constructing and developing bootstrapping methods, as well as investigating the relationship between this thinking and the drawing of informal inferences. This study demonstrates that it is possible for model development sequences to elicit and develop students’ models of bootstrapping. With the trend in statistics education of moving from the focus on theoretical distributions towards the simulation and analysis of data, these findings have implications towards the design of future introductory statistics curricula

AN EXPLORATORY STUDY ON SOCIAL LEARNING THEORY, SOCIAL BOND THEORY, EXPERIENCES WITH POLICE AND DEMOGRAPHIC EFFECTS ON COLLEGE STUDENT ATTITUDES TOWARD POLICE

Research on public attitudes toward police is principally conducted through survey methods focused on analyzing the effects of experiences with police, satisfaction with police services and respondent demographics. Most research collects data from the general public, which overall reports high levels of satisfaction with the police. However, few studies focus on the college student population and fewer integrate theoretical frameworks to explore this complex issue. This research incorporates tenets from social learning and social control theories as a conceptual framework from which the analysis is built. It also explores the role that personal and vicarious contact and demographic influences play in variations among college student attitudes toward police. To collect data for this study an internet-based survey instrument was sent electronically to every part-time and full-time student at The University of Montana attending classes in the fall 2011 semester. Questions asked respondents to report on their attitudes toward police, orientation toward crime and alcohol use, direct and vicarious experiences with police, as well as, items derived from empirically validated social learning and social bond concepts. Similar questions pertaining to the individual’s understanding of their friends and family experiences with police and criminal orientations were also included. Ordinary least squares regression is used to evaluate social learning, social bond, vicarious and direct experiences with police and demographic variable’s abilities to predict variations in college student attitudes toward police. The study’s results show that social learning and social bond derived variables, as well as, vicarious and direct experiences with police explain more of the variation in attitudes towards police than demographic variables. The social learning model explains the most variation in attitudes toward police compared to all the other stand-alone models. A complete model that incorporates all the variables provides the most robust prediction for the variation in attitudes toward police. A discussion of the limitations of the current study and recommendations for future research is also provided

Tough Vinyl: Packing In Our Record Collections

This paper seeks to illuminate a series of contradictions between the way we talk about, write about, and interact with vinyl records on the one hand, and the material and social relations required for the use, production, and disposal of vinyl records on the other. I examine vinyl as both an ethical commodity (the sonic equivalent to slow food) and as "the poison plastic"; vinyl as both a medium for "subaltern" voices and as a toxic substance that causes cancer in the bodies of working class communities of colour; and vinyl as it both preserves the dead and destroys the living. These contradictions and many more, all part of what I call the vinyl-network, are exposed throughout this paper in a process of de-fetishizing vinyl. The central argument of this paper is that the nostalgia for petrocapitalism's 20th century bounty (of which records are an iconic piece), is a dangerous fetish that perpetuates destructive social and material relations. Ultimately, I contend we need to abandon the vinyl revival and mourn the vinyl record, lest the way we listen to recorded music perpetuate the destructive economic system that is petrocapitalism, enabling it to spin on and on like a broken record. If we cannot move beyond this economic system, the dead will continue to pile up; we will repeat the same tragedies, different not in cause but in effect, as temperature and sea levels rise, as the Anthropocene Extinction Event wipes out one quarter of all mammals on earth, and as the screams of the dying are drowned out by the bourgeoisie's hi-fi. This paper concludes with the suggestion that we take the broken record that is petrocapitalism, smash it into a million pieces, and feed it to a hungry colony of soil fungi

Facilitation of student-staff partnership in development of digital learning tools through a special study module

A student-staff partnership was formed as part of a final year special study module to provide dental students the opportunity to work closely with faculty to produce high-quality e-learning resources in areas of the curriculum identified by the students as particularly difficult. The student-staff team identified the following themes as major influences on the success of the project: student-staff interaction, ownership, managing expectations, time pressures, and co-creation partnership benefits. This partnership resulted in a valuable learning experience for both the students and staff involved. The resource developed was evaluated by junior dental students in second and third year of the five year Bachelor of Dental Surgery (BDS) degree programme at Glasgow Dental School and showed a high degree of acceptability by those in both groups. The quality assurance built into the process has resulted in an e-learning resource that has been incorporated directly into our flipped classroom model for pre-clinical skills teaching

Effects of Stride Rate Manipulation in Shoes with Different Drop Heights

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Five supernova survey galaxies in the southern hemisphere. II. The supernova rates

Based on the database compiled in the first article of this series, with 56 SN events discovered in 3838 galaxies of the southern hemisphere, we compute the rate of supernovae (SNe) of different types along the Hubble sequence normalized to the optical and near-infrared luminosities as well as to the stellar mass of the galaxies. We find that the rates of all SN types show a dependence on both morphology and colors of the galaxies, and therefore, on the star-formation activity. The rate of core-collapse (CC) SNe is confirmed to be closely related to the Star Formation Rate (SFR) and only indirectly to the total mass of the galaxies. The rate of SNe Ia can be explained by assuming that at least 15% of Ia events in spiral galaxies originates in relatively young stellar populations. We find that the rates show no modulation with nuclear activity or environment. The ratio of SN rates between types Ib/c and II shows no trend with spiral type.Comment: 13 pages, 2 figures, 5 tables, published in Astrophysics (English translation of Astrofizika

Enabling High Performance Green Propulsion for SmallSats

Combining a robust semi-autonomous manufacturing capability with a new form of digital assurance is enabling Raytheon to manufacture low cost, highly reliable small satellites

Plant viruses.

Clover viruses, 82ES38, 82AL47, 82MA19, 82BR19, 82BY29; 82BU5, 82HA9. Lupin virus, diseases. Barley yellow dwarf virus, 82AL46, 82AL51, 82B10, 82BA33, 82BR16, 82BR18, 82C29, 82E27, 82ES37, 82ES40, 82JE19, 82JE20, 82KA33, 82KA34, 82ABI3, 82MA18, 82MN22, 82MT34, 82NA32, 82WH28,82B8, 82MN17, 82E24, 82MT30, 82E25, 82MN18, 82MT31, 82B9, 82ABI2, 82BA31, 82C26, 82JE17, 82WH27, 82AL45, 82BR17, 82ES39, 82MA1, 82MA117, 82MT33