Improving the External Validity of Conjoint Analysis: The Essential Role of Profile Distribution

2021 ◽  
pp. 1-27 ◽  
Author(s):  
Brandon de la Cuesta ◽  
Naoki Egami ◽  
Kosuke Imai
Keyword(s):  
Conjoint Analysis ◽  
Real World ◽  
External Validity ◽  
Causal Effect ◽  
The Other ◽  
Estimation Methods ◽  
Social Scientists ◽  
Actual Distribution ◽  
Open Source Software Package ◽  
Profile Distribution

Abstract Conjoint analysis has become popular among social scientists for measuring multidimensional preferences. When analyzing such experiments, researchers often focus on the average marginal component effect (AMCE), which represents the causal effect of a single profile attribute while averaging over the remaining attributes. What has been overlooked, however, is the fact that the AMCE critically relies upon the distribution of the other attributes used for the averaging. Although most experiments employ the uniform distribution, which equally weights each profile, both the actual distribution of profiles in the real world and the distribution of theoretical interest are often far from uniform. This mismatch can severely compromise the external validity of conjoint analysis. We empirically demonstrate that estimates of the AMCE can be substantially different when averaging over the target profile distribution instead of uniform. We propose new experimental designs and estimation methods that incorporate substantive knowledge about the profile distribution. We illustrate our methodology through two empirical applications, one using a real-world distribution and the other based on a counterfactual distribution motivated by a theoretical consideration. The proposed methodology is implemented through an open-source software package.

A Preregistered Validation Study of the Taylor Aggression Paradigm

2017 ◽  
Author(s):  
David Skylan Chester
Keyword(s):  
Aggressive Behavior ◽  
Validation Study ◽  
Real World ◽  
External Validity ◽  
State Level ◽  
Taylor Aggression Paradigm ◽  
Psychological Science ◽  
Laboratory Measure ◽  
Behavioral Tasks ◽  
Preliminary Support

The Taylor Aggression Paradigm (TAP) is a frequently-used laboratory measure of aggressive behavior. However, the flexibility inherent in its implementation and analysis can undermine its validity. To test whether the TAP was a valid aggression measure irrespective of this flexibility, I conducted a preregistered study of a 25-trial version of the TAP using a single scoring approach with 160 diverse undergraduate participants. TAP scores showed agreement with other laboratory aggression measures and were magnified by an experimental provocation manipulation. Mixed evidence was found for associations with aggressive dispositions and real-world violence. These results provide preliminary support for this approach to the TAP to measure state-level aggressive behavior. However, more evidence is needed to assess the TAP’s external validity and ability to measure dispositional forms of aggression. Using preregistered designs, researchers should validate specific variants of their behavioral tasks in order to optimize the veridicality and reproducibility of psychological science.

scholarly journals External validity of somatostatin analogues trials in advanced neuroendocrine neoplasms: the GETNE-TRASGU study

2021 ◽  
Author(s):  
Paula Jimenez-Fonseca ◽  
Alberto Carmona-Bayonas ◽  
Angela Lamarca ◽  
Jorge Barriuso ◽  
Angel Castaño ◽  
...  
Keyword(s):  
Real World ◽  
External Validity ◽  
Randomized Clinical Trials ◽  
Cox Model ◽  
Analytical Data ◽  
Somatostatin Analogues ◽  
Unknown Primary ◽  
Octreotide Lar ◽  
Well Differentiated ◽  
Lanreotide Autogel

Introduction: Somatostatin analogues (SSA) prolong progression-free survival (PFS) in patients with well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs). However, the eligibility criteria in randomized clinical trials (RCTs) have been restricted, which contrasts with the vast heterogeneity found in NETs. Methods: We identified patients with well-differentiated (Ki67% ≤20%), metastatic GEP-NETs treated in first-line with SSA monotherapy from the Spanish R-GETNE registry. The therapeutic effect was evaluated using a Bayesian Cox model. The objective was to compare survival-based outcomes from real world clinical practice versus RCTs. Results: The dataset contained 535 patients with a median age of 62 years (range: 26-89). The median Ki67% was 4 (range: 0-20). The most common primary tumor sites were: midgut, 46%; pancreas, 34%; unknown primary, 10%; and colorectal, 10%. Half of the patients received octreotide LAR (n=266) and half, lanreotide autogel (n=269). The median PFS was 28.0 months (95% CI, 22.1-32.0) for octreotide vs 30.1 months (95% CI, 23.1-38.0) for lanreotide. The overall hazard ratio for lanreotide vs octreotide was 0.90 (95% credible interval, 0.71-1.12). The probability of effect sizes >30% with lanreotide vs octreotide was 2% and 6% for midgut and foregut NENs, respectively. Conclusion: Our study evaluated the external validity of RCTs examining SSAs in the real world, as well as the main effect-modifying factors (progression status, symptoms, tumor site, specific metastases, and analytical data).. Our results indicate that both octreotide LAR and lanreotide autogel had a similar effect on PFS. Consequently, both represent valid alternatives in patients with well-differentiated, metastatic GEP-NENs.

scholarly journals COVID-19: systematic learning across boundaries requires a conceptual agreement

2021 ◽  
pp. 140349482110270
Author(s):  
Knut Ole Sundnes ◽  
Geir Sverre Braut
Keyword(s):  
Public Health ◽  
Knowledge Base ◽  
External Validity ◽  
Evaluation Research ◽  
The Other ◽  
Basic Knowledge ◽  
Early Publication ◽  
Number Of Publications ◽  
Short Time

The COVID-19 epidemic has revealed a shortage of basic knowledge and understanding of pandemics, especially regarding their dynamics and how to contain them. The results are a host of governments’ decrees and instructions, one replacing the other, often within the same week. It has further, in a truly short time, resulted in an overwhelming number of publications, many of them prioritising early publication over quality. This commentary addresses the concept of structured research related to disasters and how the use of endorsed guidelines will facilitate well-designed evaluation research with improved rigour and external validity, even if applied retrospectively. The outcome should be a solidified knowledge base. Further, the important role of public health efforts is to be highlighted, as their role has proved crucial during the COVID-19 pandemic.

scholarly journals The Pice Effects of Competition from Parallel Imports and Therapeutic Alternatives: Using Dynamic Models to Estimate the Causal Effect on the Extensive and Intensive Margins

2021 ◽  
Author(s):  
David Granlund
Keyword(s):  
Dynamic Models ◽  
Causal Effect ◽  
The Other ◽  
Causal Effects ◽  
Parallel Imports ◽  
Extensive And Intensive Margins ◽  
Price Effects ◽  
Short And Long Term ◽  
Therapeutic Alternatives

AbstractThis paper studies responses to competition with the use of dynamic models that distinguish between short- and long-term price effects. The dynamic models also allow lagged numbers of competitors to become valid and strong instruments for the current numbers, which enables studying the causal effects using flexible specifications. A first parallel trader is found to decrease prices of exchangeable products by 7% in the long term. On the other hand, prices do not respond to the first competitor that sells therapeutic alternatives; but competition from four or more competitors that sell on-patent therapeutic alternatives decreases prices by about 10% in the long term.

A Survey on Causal Inference

2021 ◽  
Vol 15 (5) ◽  
pp. 1-46
Author(s):  
Liuyi Yao ◽  
Zhixuan Chu ◽  
Sheng Li ◽  
Yaliang Li ◽  
Jing Gao ◽  
...  
Keyword(s):  
Machine Learning ◽  
Causal Inference ◽  
Observational Data ◽  
Causal Effect ◽  
Research Direction ◽  
Estimation Methods ◽  
Potential Outcome ◽  
Outcome Framework ◽  
Benchmark Datasets ◽  
Inference Methods

Causal inference is a critical research topic across many domains, such as statistics, computer science, education, public policy, and economics, for decades. Nowadays, estimating causal effect from observational data has become an appealing research direction owing to the large amount of available data and low budget requirement, compared with randomized controlled trials. Embraced with the rapidly developed machine learning area, various causal effect estimation methods for observational data have sprung up. In this survey, we provide a comprehensive review of causal inference methods under the potential outcome framework, one of the well-known causal inference frameworks. The methods are divided into two categories depending on whether they require all three assumptions of the potential outcome framework or not. For each category, both the traditional statistical methods and the recent machine learning enhanced methods are discussed and compared. The plausible applications of these methods are also presented, including the applications in advertising, recommendation, medicine, and so on. Moreover, the commonly used benchmark datasets as well as the open-source codes are also summarized, which facilitate researchers and practitioners to explore, evaluate and apply the causal inference methods.

Coming Home

1994 ◽  
Vol 19 (03) ◽  
pp. 599-603
Author(s):  
Christine B. Harrington ◽  
John Brigham
Keyword(s):  
The Other ◽  
Academic Life ◽  
Intellectual Life ◽  
Social Scientists ◽  
Ongoing Effort ◽  
English Law

Ever since the formation of an academic bar, one which left the “practical world” of apprentices and clerkships barely 100 years ago, the architects of law's intellectual life have looked outside the canons of lawyers' law to academic life and its deep thinkers for stimulation. From the German social scientists of Pound's time to Foucault in our own, the erotica of the legal academy have often been drawn from French and German philosophers and social theorists. There may be, in fact, a pattern to this inclination in America to draw insights from the “wild passion” of the French or the “dark terror” of the Germans. There is certainly an ongoing effort to avoid England in both its commonness and its construction of the “savage” or the ethnographically primitive “other” on which English law based its authority for so long. American sociolegal intellectuals, as part of the legal academy, crave a hit of the “other” on the continent of Europe, having denuded the American forests of its native occupants.

scholarly journals GazeEMD: Detecting Visual Intention in Gaze-Based Human-Robot Interaction

Robotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 68
Author(s):  
Lei Shi ◽  
Cosmin Copot ◽  
Steve Vanlanduit
Keyword(s):  
Cognitive Load ◽  
Real World ◽  
Robotic Manipulator ◽  
Similarity Score ◽  
Human Robot Interaction ◽  
Experimental Results ◽  
The Other ◽  
Robot Interaction ◽  
Run Length ◽  
The Real

In gaze-based Human-Robot Interaction (HRI), it is important to determine human visual intention for interacting with robots. One typical HRI interaction scenario is that a human selects an object by gaze and a robotic manipulator will pick up the object. In this work, we propose an approach, GazeEMD, that can be used to detect whether a human is looking at an object for HRI application. We use Earth Mover’s Distance (EMD) to measure the similarity between the hypothetical gazes at objects and the actual gazes. Then, the similarity score is used to determine if the human visual intention is on the object. We compare our approach with a fixation-based method and HitScan with a run length in the scenario of selecting daily objects by gaze. Our experimental results indicate that the GazeEMD approach has higher accuracy and is more robust to noises than the other approaches. Hence, the users can lessen cognitive load by using our approach in the real-world HRI scenario.

Peer Sharing Facilitates the Effect of Inquiry-based Projects on Science Learning

2010 ◽  
Vol 72 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Hui-Min Chung ◽  
Kristina Jackson Behan
Keyword(s):  
Popular Culture ◽  
Real World ◽  
Scientific Inquiry ◽  
Science Learning ◽  
Group Learning ◽  
Authentic Assessment ◽  
The Other ◽  
Learning Activity ◽  
Millennial Students ◽  
Inquiry Based Learning

Authentic assessment exercises are similar to real-world tasks that would be expected by a professional. An authentic assessment in combination with an inquiry-based learning activity enhances students' learning and rehearses them for their future roles, whether as scientists or as informed citizens. Over a period of 2 years, we experimented with two inquiry-based projects; one had traditional scientific inquiry characteristics, and the other used popular culture as the medium of inquiry. We found that activities that incorporated group learning motivated students and sharpened their abilities to apply and communicate their knowledge of science. We also discovered that incorporating popular culture provided ““Millennial”” students with a refreshing view of science learning and increased their appetites to explore and elaborate on science.

ERGUN ÖZBUDUN, Contemporary Turkish Politics: Challenges to Democratic Consolidation (Boulder, Colo.: Lynne Rienner, 2000). Pp. 181. $49.95 cloth.

2001 ◽  
Vol 33 (4) ◽  
pp. 657-660
Author(s):  
Frank Tachau
Keyword(s):  
Middle East ◽  
Current Literature ◽  
Real World ◽  
Democratic Consolidation ◽  
World Politics ◽  
The Other ◽  
Southern Europe ◽  
Turkish Politics ◽  
Political Studies

Based on Professor Özbudun's lectures at Bilkent University, this book is at once compact, highly readable, and very insightful. Unlike much current literature on Turkey, the analysis is set in a broad and informed comparative context. Turkey, the author points out, has been left out of comparative political studies, particularly those encompassing the Middle East and southern Europe, in which arguably it could (or should) have been included. Scholarly neglect thus reflects real-world politics: Turkey falls between two worlds, one of which it once largely controlled, the other to which it currently aspires to belong. This lacuna is one of the factors that persuaded Özbudun to publish this volume.

scholarly journals An Optimal and Stable Algorithm for Clustering Numerical Data

Algorithms ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 197
Author(s):  
Ali Seman ◽  
Azizian Mohd Sapawi
Keyword(s):  
Standard Deviation ◽  
Real World ◽  
Clustering Algorithm ◽  
Numerical Data ◽  
Zero Point ◽  
The Other ◽  
Suitable Alternative ◽  
Stable Algorithm ◽  
Real World Applications

In the conventional k-means framework, seeding is the first step toward optimization before the objects are clustered. In random seeding, two main issues arise: the clustering results may be less than optimal and different clustering results may be obtained for every run. In real-world applications, optimal and stable clustering is highly desirable. This report introduces a new clustering algorithm called the zero k-approximate modal haplotype (Zk-AMH) algorithm that uses a simple and novel seeding mechanism known as zero-point multidimensional spaces. The Zk-AMH provides cluster optimality and stability, therefore resolving the aforementioned issues. Notably, the Zk-AMH algorithm yielded identical mean scores to maximum, and minimum scores in 100 runs, producing zero standard deviation to show its stability. Additionally, when the Zk-AMH algorithm was applied to eight datasets, it achieved the highest mean scores for four datasets, produced an approximately equal score for one dataset, and yielded marginally lower scores for the other three datasets. With its optimality and stability, the Zk-AMH algorithm could be a suitable alternative for developing future clustering tools.

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