Field Experiments and Natural Experiments

2009 ◽  
Author(s):  
Alan S. Gerber ◽  
Donald P. Green
Keyword(s):  
Experimental Design ◽  
Growth And Development ◽  
Field Experiments ◽  
Observational Research ◽  
Natural Experiments ◽  
Methodological Issues ◽  
Political Methodology ◽  
Field Experimentation ◽  
The Many

This article evaluates the strengths and limitations of field experimentation. It first defines field experimentation and describes the many forms that field experiments take. It also interprets the growth and development of field experimentation. It then discusses why experiments are valuable for causal inference. The assumptions of experimental and nonexperimental inference are distinguished, noting that the value accorded to observational research is often inflated by misleading reporting conventions. The article elaborates on the study of natural experiments and discontinuities as alternatives to both randomized interventions and conventional nonexperimental research. Finally, it outlines a list of methodological issues that arise commonly in connection with experimental design and analysis: the role of covariates, planned vs. unplanned comparisons, and extrapolation. It concludes by dealing with the ways in which field experimentation is reshaping the field of political methodology.

8. Experimental Research

2017 ◽  
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Experimental Design ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Ethical Issues ◽  
Natural Experiments ◽  
The Common ◽  
Internal And External Validity

This chapter explores the principles of experimental research design as well as the issues and problems associated with different aspects of the approach. In particular, it considers the issue of internal and external validity, the common obstacles associated with experimental research, and what can be done to try and avoid or minimize them. The chapter first describes the five steps involved in the classic version of the experimental design before discussing three types of experimental design: laboratory experiments, field experiments, and natural experiments. It also examines the ethical issues that arise from experimental research and concludes by highlighting some of the advantages of experimental research.

scholarly journals PENGARUH PEMBERIAN DAUN BANGUN – BANGUN (COLEUS AMBONICUS LOUR ) TERHADAP PRODUKSI ASI

2019 ◽  
Vol 1 (2) ◽  
pp. 23-28
Author(s):  
Putri Ayu Yessy Ariescha ◽  
Ucy Tryaningsih
Keyword(s):  
Experimental Design ◽  
Breast Milk ◽  
Exclusive Breastfeeding ◽  
Growth And Development ◽  
Control Design ◽  
Total Sample ◽  
Case Group ◽  
Formula Milk ◽  
Breast Milk Production ◽  
The Many

Exclusive breastfeeding is very important for babies aged 0-6 months and must be given in the first hour. Exclusive breastfeeding is one of the most powerful influences on children's survival, growth and development. Despite the many benefits of breastfeeding, the coverage of exclusive breastfeeding is still low. One of the causes of mothers not giving breast milk because the milk comes out very little. So the mother gives formula milk. This study aims to determine the production of breast milk produced in mothers who were given Daun Bangun-Bangun soup and analyze the effect of giving Daun Bangun-Bangun on breast milk production in Desa Biru-Biru in Candirejo. The design of this study was quasy experimental design with a total sample of 32 people with a total sampling. 16 respondent as case group dan 16 responden as intervension group. With the type of Posttest-Only Control Design. The results of the study showed that there was a significant effect of Daun Bangun-Bangun to the production of breast milk. Significant results indicate that p = 0,000 <0,005.

8. Experimental Research

2020 ◽  
pp. 211-230
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Experimental Design ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Ethical Issues ◽  
Natural Experiments ◽  
The Common ◽  
Internal And External Validity

This chapter explores the principles of experimental research design as well as the issues and problems associated with different aspects of the approach. In particular, it considers the issue of internal and external validity, the common obstacles associated with experimental research, and what can be done to try and avoid or minimize them. The chapter first describes the five steps involved in the classic version of the experimental design before discussing three types of experimental design: laboratory experiments, field experiments, and natural experiments. It also examines the ethical issues that arise from experimental research and concludes by highlighting some of the advantages of experimental research.

Natural Experiments and Causality in Economic History: On Their Relations to Theory and Temporality

2017 ◽  
Vol 72 (4) ◽  
pp. 699-728
Author(s):  
Sacha Bourgeois-Gironde ◽  
Éric Monnet
Keyword(s):  
Economic History ◽  
Historical Analysis ◽  
Natural Experiments ◽  
Long Term Effects ◽  
The Many ◽  
Definition Of ◽  
Implicit And Explicit ◽  
Common Understanding

A recent and influential research methodology, mainly endorsed by economists, proposes to renew historical analysis based on the notions of natural experiment and causality. It has the dual ambition of unifying various disciplines around a common understanding of causality in order to tackle major historical questions (such as the role of colonization, political regimes, or religion in economic development) and of making the analysis of history more scientific. The definition of causality it promotes—of the “interventionist” type—tends to liken historical events to laboratory experiments. This is articulated with a neo-institutionalist perspective aimed at measuring the long-term effects of past institutional changes, which are considered exogenous. In the first part of this article, we present the ambitions, contributions, methods, and hypotheses (implicit and explicit) of this approach, showing how it differs from more traditional quantitative economic history and placing it in the context of the recent empirical and neo-institutionalist “turns” of the economic discipline. In a second stage, we consider the criticism—often scathing—voiced by historians or economists against this method and its objectives. Finally, we emphasize the many difficulties posed by this approach when it comes to taking into account the historicity of phenomena, to producing general statements based on particular cases, and to providing a complete and coherent definition of causality in history.

Identifying suboptimalities with factorial model comparison

2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma
Keyword(s):  
Experimental Design ◽  
Model Comparison ◽  
Process Models ◽  
Multiple Forms ◽  
Factorial Experimental Design ◽  
Factorial Model ◽  
Multiple Components ◽  
The Many

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Everybody Follows the Crowd?

2017 ◽  
Vol 29 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Magdalena Obermaier ◽  
Thomas Koch ◽  
Christian Baden
Keyword(s):  
Experimental Design ◽  
News Coverage ◽  
Personal Characteristics ◽  
Election Campaigns ◽  
Bandwagon Effect ◽  
Political News ◽  
Election Results ◽  
Opinion Polls ◽  
Electoral Preferences

Abstract. Opinion polls are a well-established part of political news coverage, especially during election campaigns. At the same time, there has been controversial debate over the possible influences of such polls on voters’ electoral choices. The most prominent influence discussed is the bandwagon effect: It states that voters tend to support the expected winner of an upcoming election, and use polls to determine who the likely winner will be. This study investigated the mechanisms underlying the effect. In addition, we inquired into the role of past electoral performances of a candidate and analyzed how these (as well as polls) are used as heuristic cues for the assessment of a candidate’s personal characteristics. Using an experimental design, we found that both polls and past election results influence participants’ expectations regarding which candidate will succeed. Moreover, higher competence was attributed to a candidate, if recipients believe that the majority of voters favor that candidate. Through this attribution of competence, both information about prior elections and current polls shaped voters’ electoral preferences.

The future role of the psychiatrist in Europe – a UEMS perspective

2014 ◽  
Vol 11 (01) ◽  
pp. 35-42
Author(s):  
M. Hermans
Keyword(s):  
Mental Health ◽  
Mental Health Professionals ◽  
Health Professionals ◽  
General Interest ◽  
Future Role ◽  
Personal Opinion ◽  
The Future ◽  
The Subject ◽  
The Many

SummaryThe author presents his personal opinion inviting to discussion on the possible future role of psychiatrists. His view is based upon the many contacts with psychiatrists all over Europe, academicians and everyday professionals, as well as the familiarity with the literature. The list of papers referred to is based upon (1) the general interest concerning the subject when representing ideas also worded elsewhere, (2) the accessibility to psychiatrists and mental health professionals in Germany, (3) being costless downloadable for non-subscribers and (4) for some geographic aspects (e.g. Belgium, Spain, Sweden) and the latest scientific issues, addressing some authors directly.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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