Sample Selection in Randomized Trials With Multiple Target Populations

2022 ◽  
pp. 109821402092778
Author(s):  
Elizabeth Tipton

Practitioners and policymakers often want estimates of the effect of an intervention for their local community, e.g., region, state, county. In the ideal, these multiple population average treatment effect (ATE) estimates will be considered in the design of a single randomized trial. Methods for sample selection for generalizing the sample ATE to date, however, focus only on the case of a single target population. In this paper, I provide a framework for sample selection in the multiple population case, including three compromise allocations. I situate the methods in an example and conclude with a discussion of the implications for the design of randomized evaluations more generally.

2017 ◽  
Vol 4 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Annie Franco ◽  
Neil Malhotra ◽  
Gabor Simonovits ◽  
L. J. Zigerell

AbstractWeighting techniques are employed to generalize results from survey experiments to populations of theoretical and substantive interest. Although weighting is often viewed as a second-order methodological issue, these adjustment methods invoke untestable assumptions about the nature of sample selection and potential heterogeneity in the treatment effect. Therefore, although weighting is a useful technique in estimating population quantities, it can introduce bias and also be used as a researcher degree of freedom. We review survey experiments published in three major journals from 2000–2015 and find that there are no standard operating procedures for weighting survey experiments. We argue that all survey experiments should report the sample average treatment effect (SATE). Researchers seeking to generalize to a broader population can weight to estimate the population average treatment effect (PATE), but should discuss the construction and application of weights in a detailed and transparent manner given the possibility that weighting can introduce bias.


Author(s):  
Yohei Koizumi ◽  
Masayuki Kuzuhara ◽  
Masashi Omiya ◽  
Teruyuki Hirano ◽  
John Wisniewski ◽  
...  

Abstract We present the optical spectra of 338 nearby M dwarfs, and compute their spectral types, effective temperatures (Teff), and radii. Our spectra were obtained using several optical spectrometers with spectral resolutions that range from 1200 to 10000. As many as 97% of the observed M-type dwarfs have a spectral type of M3–M6, with a typical error of 0.4 subtype, among which the spectral types M4–M5 are the most common. We infer the Teff of our sample by fitting our spectra with theoretical spectra from the PHOENIX model. Our inferred Teff is calibrated with the optical spectra of M dwarfs whose Teff have been well determined with the calibrations that are supported by previous interferometric observations. Our fitting procedures utilize the VO absorption band (7320–7570 Å) and the optical region (5000–8000 Å), yielding typical errors of 128 K (VO band) and 85 K (optical region). We also determine the radii of our sample from their spectral energy distributions. We find most of our sample stars have radii of <0.6 R⊙, with the average error being 3%. Our catalog enables efficient sample selection for exoplanet surveys around nearby M-type dwarfs.


Author(s):  
Jeremy A. Decker ◽  
Samantha H. Haus ◽  
Rini Sherony ◽  
Hampton C. Gabler

In 2015, there were 319,195 police reported vehicle-animal crashes, resulting in 275 vehicle occupant fatalities. Animal-detecting automatic emergency braking (AEB) systems are a promising active safety measure which could potentially avoid or mitigate many of these crashes by warning the driver, utilizing automatic braking, or both. The purpose of this study was to develop and characterize a target population of vehicle-animal crashes applicable to AEB systems and to analyze the potential benefits of an animal-detecting AEB system. The study was based on two nationally representative databases, Fatality Analysis Reporting System and the National Automotive Sampling System’s General Estimates System, and a naturalistic driving study, SHRP 2. The target population was restricted to vehicle-animal crashes that were forward impacts or road departures and involved cars and light trucks, with no loss of control. Crash characteristics which may influence the performance of AEB such as lighting, weather, pre-crash movement, relation to junction, and first and worst harmful events, were analyzed. The study found that the major influences on the effectiveness of animal AEB systems were: weather, lighting, pre-crash movements, and the crash location. Six potential target populations were used to analyze the potential effectiveness of an animal AEB system, with effectiveness ranging between 21.6% and 97% of police reported crashes and between 4.1% and 50.8% of fatal vehicle-animal crashes. An AEB system’s ability to function in low light and poor weather conditions may enable it to avoid a substantially higher proportion of crashes.


2005 ◽  
Vol 26 (1) ◽  
pp. 41-64 ◽  
Author(s):  
CAROLYN B. MERVIS ◽  
BYRON F. ROBINSON

Accurate phenotypic description is critical for the success of studies of the genetic basis for developmental language disorders. An important purpose of such a phenotypic description is to differentiate the language and associated cognitive profiles of syndromes or other developmental language disorders with diverse genotypes. In this paper we consider six measurement issues relevant to genotype/phenotype research and profiling: (a) Who is the target population? (b) What is the “ideal” measure of a single component of language? (c) What is the “ideal” measure(s) for quantifying the language (or language and cognitive) profile for a particular syndrome or disorder? (d) What are the special measurement issues for infants and young children? (e) How do we develop a profile? (f) What are the unresolved issues?


Retos ◽  
2015 ◽  
pp. 42-47
Author(s):  
Angeles Filgueira Perez

En el presente estudio se ha tratado de obtener una aproximación al perfil ideal del entrenador de alto rendimiento en atletismo. En el mundo del deporte de alta competición, el entrenador debe desarrollar funciones de maestro, técnico y líder, lo cual hace difícil delimitar sus competencias (conocimientos, habilidades y cualidades personales). Por tanto, la principal motivación de este trabajo es establecer el papel que debe desempeñar el entrenador para la preparación física, técnica, táctica, psicológica y moral del deportista de alto nivel. Para ello, se ha considerado como población objeto de estudio al conjunto de entrenadores de alto rendimiento que en el momento de la investigación estuviesen activo, ya que interesaba realizar este estudio desde su propia perspectiva. Los datos recogidos forman parte de una investigación más amplia, llevada a cabo mediante encuesta, para la que se diseñó un cuestionario de 78 preguntas en el que se abarcaban tres temas: el perfil del entrenador y del deportista, así como la figura del formador de entrenadores en el Practicum. En este trabajo nos centramos en el primer tema y el análisis de la información obtenida nos permite concluir que la que práctica totalidad de los entrenadores de atletismo consideran necesario dominar con precisión los aspectos técnico-metodológicos. Además, consideran que su ética profesional debe estar regida por los principios de autonomía y beneficencia, de modo que valores como la honestidad y la justicia deben primar en el desarrollo de sus funciones.Abstract: In the current study, we have tried to get an approximation of the ideal profile of high performance coaches in athletics. In the high-level sports world, the coach must develop the role of teacher, technician and leader,  which makes it difficult to delimit  his/her competencies (knowledge, skills and personal qualities). Therefore, the main motivation of this work is to define the role that the coach plays in relation  to the physical, technical, tactical, psychological and moral preparation of elite athletes. Keeping this aim as an objective, we have considered as the target population the high performance coaches who are active at the time of the investigation, since we were interested  in knowing their own perspective. The data that was collected is a part of a wider investigation, conducted by a survey, for which we designed a questionnaire of 78 questions divided on three topics: the profile of the coach and the athlete, as well as the figure of the coach educator in the Practicum. In this work, we focus on the first topic and the analysis of the information that we obtained allows us to conclude that almost all the track and field coaches find it necessary to dominate the technical and methodological aspects. They also consider that professional ethics must be governed by the principles of autonomy and care that values   like honesty and justice must prevail in the performance of their work.


1997 ◽  
Vol 49 (4) ◽  
pp. 567-585 ◽  
Author(s):  
Yulong Cui ◽  
Kenneth L. Verosub ◽  
Andrew P. Roberts ◽  
Mary Kovacheva

2016 ◽  
Vol 31 (1) ◽  
pp. 89-112
Author(s):  
Na Chong Min

This paper discusses limitations of the ???black-box??? experimental archetype by highlighting the narrowness of outcome-focused approaches. For a more complete understanding of the nuanced implications of policies and programs, this study calls for an investigation of causal mechanism and treatment effect heterogeneity in experimentally evaluated interventions. This study draws on two distinct but closely related empirical studies, one undertaken by Na and Paternoster (2012) and the other by Na, Loughran, and Paternoster (2015), that go beyond the estimation of a population average treatment effect by adopting more recent methodological advancements that are still underappreciated and underutilized in evaluation research.


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