The Effective Use of Secondary Data
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Introduction to Biostatistics
Introduction to Biostatistics Jie Yang, Ph.D. Associate Professor Department of Family, Population and Preventive Medicine Director Biostatistical Consulting Core Director Biostatistics and Bioinformatics Shared Resource, Stony Brook Cancer Center In collaboration with Clinical Translational Science Center (CTSC) and the Biostatistics and Bioinformatics Shared Resource (BB-SR), Stony Brook Cancer Center (SBCC). OUTLINE What is Biostatistics What does a biostatistician do • Experiment design, clinical trial design • Descriptive and Inferential analysis • Result interpretation What you should bring while consulting with a biostatistician WHAT IS BIOSTATISTICS • The science of (bio)statistics encompasses the design of biological/clinical experiments the collection, summarization, and analysis of data from those experiments the interpretation of, and inference from, the results How to Lie with Statistics (1954) by Darrell Huff. http://www.youtube.com/watch?v=PbODigCZqL8 GOAL OF STATISTICS Sampling POPULATION Probability SAMPLE Theory Descriptive Descriptive Statistics Statistics Inference Population Sample Parameters: Inferential Statistics Statistics: 흁, 흈, 흅… 푿ഥ , 풔, 풑ෝ,… PROPERTIES OF A “GOOD” SAMPLE • Adequate sample size (statistical power) • Random selection (representative) Sampling Techniques: 1.Simple random sampling 2.Stratified sampling 3.Systematic sampling 4.Cluster sampling 5.Convenience sampling STUDY DESIGN EXPERIEMENT DESIGN Completely Randomized Design (CRD) - Randomly assign the experiment units to the treatments -
DATA COLLECTION METHODS Section III 5
AN OVERVIEW OF QUANTITATIVE AND QUALITATIVE DATA COLLECTION METHODS Section III 5. DATA COLLECTION METHODS: SOME TIPS AND COMPARISONS In the previous chapter, we identified two broad types of evaluation methodologies: quantitative and qualitative. In this section, we talk more about the debate over the relative virtues of these approaches and discuss some of the advantages and disadvantages of different types of instruments. In such a debate, two types of issues are considered: theoretical and practical. Theoretical Issues Most often these center on one of three topics: · The value of the types of data · The relative scientific rigor of the data · Basic, underlying philosophies of evaluation Value of the Data Quantitative and qualitative techniques provide a tradeoff between breadth and depth, and between generalizability and targeting to specific (sometimes very limited) populations. For example, a quantitative data collection methodology such as a sample survey of high school students who participated in a special science enrichment program can yield representative and broadly generalizable information about the proportion of participants who plan to major in science when they get to college and how this proportion differs by gender. But at best, the survey can elicit only a few, often superficial reasons for this gender difference. On the other hand, separate focus groups (a qualitative technique related to a group interview) conducted with small groups of men and women students will provide many more clues about gender differences in the choice of science majors, and the extent to which the special science program changed or reinforced attitudes. The focus group technique is, however, limited in the extent to which findings apply beyond the specific individuals included in the groups. -
Experimentation Science: a Process Approach for the Complete Design of an Experiment
Kansas State University Libraries New Prairie Press Conference on Applied Statistics in Agriculture 1996 - 8th Annual Conference Proceedings EXPERIMENTATION SCIENCE: A PROCESS APPROACH FOR THE COMPLETE DESIGN OF AN EXPERIMENT D. D. Kratzer K. A. Ash Follow this and additional works at: https://newprairiepress.org/agstatconference Part of the Agriculture Commons, and the Applied Statistics Commons This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License. Recommended Citation Kratzer, D. D. and Ash, K. A. (1996). "EXPERIMENTATION SCIENCE: A PROCESS APPROACH FOR THE COMPLETE DESIGN OF AN EXPERIMENT," Conference on Applied Statistics in Agriculture. https://doi.org/ 10.4148/2475-7772.1322 This is brought to you for free and open access by the Conferences at New Prairie Press. It has been accepted for inclusion in Conference on Applied Statistics in Agriculture by an authorized administrator of New Prairie Press. For more information, please contact [email protected]. Conference on Applied Statistics in Agriculture Kansas State University Applied Statistics in Agriculture 109 EXPERIMENTATION SCIENCE: A PROCESS APPROACH FOR THE COMPLETE DESIGN OF AN EXPERIMENT. D. D. Kratzer Ph.D., Pharmacia and Upjohn Inc., Kalamazoo MI, and K. A. Ash D.V.M., Ph.D., Town and Country Animal Hospital, Charlotte MI ABSTRACT Experimentation Science is introduced as a process through which the necessary steps of experimental design are all sufficiently addressed. Experimentation Science is defined as a nearly linear process of objective formulation, selection of experimentation unit and decision variable(s), deciding treatment, design and error structure, defining the randomization, statistical analyses and decision procedures, outlining quality control procedures for data collection, and finally analysis, presentation and interpretation of results. -
Data Extraction for Complex Meta-Analysis (Decimal) Guide
Pedder, H. , Sarri, G., Keeney, E., Nunes, V., & Dias, S. (2016). Data extraction for complex meta-analysis (DECiMAL) guide. Systematic Reviews, 5, [212]. https://doi.org/10.1186/s13643-016-0368-4 Publisher's PDF, also known as Version of record License (if available): CC BY Link to published version (if available): 10.1186/s13643-016-0368-4 Link to publication record in Explore Bristol Research PDF-document This is the final published version of the article (version of record). It first appeared online via BioMed Central at http://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-016-0368-4. Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Pedder et al. Systematic Reviews (2016) 5:212 DOI 10.1186/s13643-016-0368-4 RESEARCH Open Access Data extraction for complex meta-analysis (DECiMAL) guide Hugo Pedder1*, Grammati Sarri2, Edna Keeney3, Vanessa Nunes1 and Sofia Dias3 Abstract As more complex meta-analytical techniques such as network and multivariate meta-analyses become increasingly common, further pressures are placed on reviewers to extract data in a systematic and consistent manner. Failing to do this appropriately wastes time, resources and jeopardises accuracy. This guide (data extraction for complex meta-analysis (DECiMAL)) suggests a number of points to consider when collecting data, primarily aimed at systematic reviewers preparing data for meta-analysis. -
Reasoning with Qualitative Data: Using Retroduction with Transcript Data
Reasoning With Qualitative Data: Using Retroduction With Transcript Data © 2019 SAGE Publications, Ltd. All Rights Reserved. This PDF has been generated from SAGE Research Methods Datasets. SAGE SAGE Research Methods Datasets Part 2019 SAGE Publications, Ltd. All Rights Reserved. 2 Reasoning With Qualitative Data: Using Retroduction With Transcript Data Student Guide Introduction This example illustrates how different forms of reasoning can be used to analyse a given set of qualitative data. In this case, I look at transcripts from semi-structured interviews to illustrate how three common approaches to reasoning can be used. The first type (deductive approaches) applies pre-existing analytical concepts to data, the second type (inductive reasoning) draws analytical concepts from the data, and the third type (retroductive reasoning) uses the data to develop new concepts and understandings about the issues. The data source – a set of recorded interviews of teachers and students from the field of Higher Education – was collated by Dr. Christian Beighton as part of a research project designed to inform teacher educators about pedagogies of academic writing. Interview Transcripts Interviews, and their transcripts, are arguably the most common data collection tool used in qualitative research. This is because, while they have many drawbacks, they offer many advantages. Relatively easy to plan and prepare, interviews can be flexible: They are usually one-to one but do not have to be so; they can follow pre-arranged questions, but again this is not essential; and unlike more impersonal ways of collecting data (e.g., surveys or observation), they Page 2 of 13 Reasoning With Qualitative Data: Using Retroduction With Transcript Data SAGE SAGE Research Methods Datasets Part 2019 SAGE Publications, Ltd. -
Double Blind Trials Workshop
Double Blind Trials Workshop Introduction These activities demonstrate how double blind trials are run, explaining what a placebo is and how the placebo effect works, how bias is removed as far as possible and how participants and trial medicines are randomised. Curriculum Links KS3: Science SQA Access, Intermediate and KS4: Biology Higher: Biology Keywords Double-blind trials randomisation observer bias clinical trials placebo effect designing a fair trial placebo Contents Activities Materials Activity 1 Placebo Effect Activity Activity 2 Observer Bias Activity 3 Double Blind Trial Role Cards for the Double Blind Trial Activity Testing Layout Background Information Medicines undergo a number of trials before they are declared fit for use (see classroom activity on Clinical Research for details). In the trial in the second activity, pupils compare two potential new sunscreens. This type of trial is done with healthy volunteers to see if the there are any side effects and to provide data to suggest the dosage needed. If there were no current best treatment then this sort of trial would also be done with patients to test for the effectiveness of the new medicine. How do scientists make sure that medicines are tested fairly? One thing they need to do is to find out if their tests are free of bias. Are the medicines really working, or do they just appear to be working? One difficulty in designing fair tests for medicines is the placebo effect. When patients are prescribed a treatment, especially by a doctor or expert they trust, the patient’s own belief in the treatment can cause the patient to produce a response. -
Observational Studies and Bias in Epidemiology
The Young Epidemiology Scholars Program (YES) is supported by The Robert Wood Johnson Foundation and administered by the College Board. Observational Studies and Bias in Epidemiology Manuel Bayona Department of Epidemiology School of Public Health University of North Texas Fort Worth, Texas and Chris Olsen Mathematics Department George Washington High School Cedar Rapids, Iowa Observational Studies and Bias in Epidemiology Contents Lesson Plan . 3 The Logic of Inference in Science . 8 The Logic of Observational Studies and the Problem of Bias . 15 Characteristics of the Relative Risk When Random Sampling . and Not . 19 Types of Bias . 20 Selection Bias . 21 Information Bias . 23 Conclusion . 24 Take-Home, Open-Book Quiz (Student Version) . 25 Take-Home, Open-Book Quiz (Teacher’s Answer Key) . 27 In-Class Exercise (Student Version) . 30 In-Class Exercise (Teacher’s Answer Key) . 32 Bias in Epidemiologic Research (Examination) (Student Version) . 33 Bias in Epidemiologic Research (Examination with Answers) (Teacher’s Answer Key) . 35 Copyright © 2004 by College Entrance Examination Board. All rights reserved. College Board, SAT and the acorn logo are registered trademarks of the College Entrance Examination Board. Other products and services may be trademarks of their respective owners. Visit College Board on the Web: www.collegeboard.com. Copyright © 2004. All rights reserved. 2 Observational Studies and Bias in Epidemiology Lesson Plan TITLE: Observational Studies and Bias in Epidemiology SUBJECT AREA: Biology, mathematics, statistics, environmental and health sciences GOAL: To identify and appreciate the effects of bias in epidemiologic research OBJECTIVES: 1. Introduce students to the principles and methods for interpreting the results of epidemio- logic research and bias 2. -
Chapter 5 Statistical Inference
Chapter 5 Statistical Inference CHAPTER OUTLINE Section 1 Why Do We Need Statistics? Section 2 Inference Using a Probability Model Section 3 Statistical Models Section 4 Data Collection Section 5 Some Basic Inferences In this chapter, we begin our discussion of statistical inference. Probability theory is primarily concerned with calculating various quantities associated with a probability model. This requires that we know what the correct probability model is. In applica- tions, this is often not the case, and the best we can say is that the correct probability measure to use is in a set of possible probability measures. We refer to this collection as the statistical model. So, in a sense, our uncertainty has increased; not only do we have the uncertainty associated with an outcome or response as described by a probability measure, but now we are also uncertain about what the probability measure is. Statistical inference is concerned with making statements or inferences about char- acteristics of the true underlying probability measure. Of course, these inferences must be based on some kind of information; the statistical model makes up part of it. Another important part of the information will be given by an observed outcome or response, which we refer to as the data. Inferences then take the form of various statements about the true underlying probability measure from which the data were obtained. These take a variety of forms, which we refer to as types of inferences. The role of this chapter is to introduce the basic concepts and ideas of statistical inference. The most prominent approaches to inference are discussed in Chapters 6, 7, and 8. -
Design of Experiments and Data Analysis,” 2012 Reliability and Maintainability Symposium, January, 2012
Copyright © 2012 IEEE. Reprinted, with permission, from Huairui Guo and Adamantios Mettas, “Design of Experiments and Data Analysis,” 2012 Reliability and Maintainability Symposium, January, 2012. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of ReliaSoft Corporation's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it. 2012 Annual RELIABILITY and MAINTAINABILITY Symposium Design of Experiments and Data Analysis Huairui Guo, Ph. D. & Adamantios Mettas Huairui Guo, Ph.D., CPR. Adamantios Mettas, CPR ReliaSoft Corporation ReliaSoft Corporation 1450 S. Eastside Loop 1450 S. Eastside Loop Tucson, AZ 85710 USA Tucson, AZ 85710 USA e-mail: [email protected] e-mail: [email protected] Tutorial Notes © 2012 AR&MS SUMMARY & PURPOSE Design of Experiments (DOE) is one of the most useful statistical tools in product design and testing. While many organizations benefit from designed experiments, others are getting data with little useful information and wasting resources because of experiments that have not been carefully designed. Design of Experiments can be applied in many areas including but not limited to: design comparisons, variable identification, design optimization, process control and product performance prediction. Different design types in DOE have been developed for different purposes. -
A Randomized Control Trial Evaluating the Effects of Police Body-Worn
A randomized control trial evaluating the effects of police body-worn cameras David Yokuma,b,1,2, Anita Ravishankara,c,d,1, and Alexander Coppocke,1 aThe Lab @ DC, Office of the City Administrator, Executive Office of the Mayor, Washington, DC 20004; bThe Policy Lab, Brown University, Providence, RI 02912; cExecutive Office of the Chief of Police, Metropolitan Police Department, Washington, DC 20024; dPublic Policy and Political Science Joint PhD Program, University of Michigan, Ann Arbor, MI 48109; and eDepartment of Political Science, Yale University, New Haven, CT 06511 Edited by Susan A. Murphy, Harvard University, Cambridge, MA, and approved March 21, 2019 (received for review August 28, 2018) Police body-worn cameras (BWCs) have been widely promoted as The existing evidence on whether BWCs have the anticipated a technological mechanism to improve policing and the perceived effects on policing outcomes remains relatively limited (17–19). legitimacy of police and legal institutions, yet evidence of their Several observational studies have evaluated BWCs by compar- effectiveness is limited. To estimate the effects of BWCs, we con- ing the behavior of officers before and after the introduction of ducted a randomized controlled trial involving 2,224 Metropolitan BWCs into the police department (20, 21). Other studies com- Police Department officers in Washington, DC. Here we show pared officers who happened to wear BWCs to those without (15, that BWCs have very small and statistically insignificant effects 22, 23). The causal inferences drawn in those studies depend on on police use of force and civilian complaints, as well as other strong assumptions about whether, after statistical adjustments policing activities and judicial outcomes. -
Data Collection, Data Quality and the History of Cause-Of-Death Classifi Cation
Chapter 8 Data Collection, Data Quality and the History of Cause-of-Death Classifi cation Vladimir Shkolnikov , France Meslé , and Jacques Vallin Until 1996, when INED published its work on trends in causes of death in Russia (Meslé et al . 1996 ) , there had been no overall study of cause-specifi c mortality for the Soviet Union as a whole or for any of its constituent republics. Yet at least since the 1920s, all the republics had had a modern system for registering causes of death, and the information gathered had been subject to routine statistical use at least since the 1950s. The fi rst reason for the gap in the literature was of course that, before perestroika, these data were not published systematically and, from 1974, had even been kept secret. A second reason was probably that researchers were often ques- tioning the data quality; however, no serious study has ever proved this. On the contrary, it seems to us that all these data offer a very rich resource for anyone attempting to track and understand cause-specifi c mortality trends in the countries of the former USSR – in our case, in Ukraine. Even so, a great deal of effort was required to trace, collect and computerize the various archived data deposits. This chapter will start with a brief description of the registration system and a quick summary of the diffi culties we encountered and the data collection methods we used. We shall then review the results of some studies that enabled us to assess the quality of the data. -
INTRODUCTION, HISTORY SUBJECT and TASK of STATISTICS, CENTRAL STATISTICAL OFFICE ¢ SZTE Mezőgazdasági Kar, Hódmezővásárhely, Andrássy Út 15
STATISTISTATISTICSCS INTRODUCTION, HISTORY SUBJECT AND TASK OF STATISTICS, CENTRAL STATISTICAL OFFICE SZTE Mezőgazdasági Kar, Hódmezővásárhely, Andrássy út 15. GPS coordinates (according to GOOGLE map): 46.414908, 20.323209 AimAim ofof thethe subjectsubject Name of the subject: Statistics Curriculum codes: EMA15121 lect , EMA151211 pract Weekly hours (lecture/seminar): (2 x 45’ lectures + 2 x 45’ seminars) / week Semester closing requirements: Lecture: exam (2 written); seminar: 2 written Credit: Lecture: 2; seminar: 1 Suggested semester : 2nd semester Pre-study requirements: − Fields of training: For foreign students Objective: Students learn and utilize basic statistical techniques in their engineering work. The course is designed to acquaint students with the basic knowledge of the rules of probability theory and statistical calculations. The course helps students to be able to apply them in practice. The areas to be acquired: data collection, information compressing, comparison, time series analysis and correlation study, reviewing the overall statistical services, land use, crop production, production statistics, price statistics and the current system of structural business statistics. Suggested literature: Abonyiné Palotás, J., 1999: Általános statisztika alkalmazása a társadalmi- gazdasági földrajzban. Use of general statistics in socio-economic geography.) JATEPress, Szeged, 123 p. Szűcs, I., 2002: Alkalmazott Statisztika. (Applied statistics.) Agroinform Kiadó, Budapest, 551 p. Reiczigel J., Harnos, A., Solymosi, N., 2007: Biostatisztika nem statisztikusoknak. (Biostatistics for non-statisticians.) Pars Kft. Nagykovácsi Rappai, G., 2001: Üzleti statisztika Excellel. (Business statistics with excel.) KSH Hunyadi, L., Vita L., 2008: Statisztika I. (Statistics I.) Aula Kiadó, Budapest, 348 p. Hunyadi, L., Vita, L., 2008: Statisztika II. (Statistics II.) Aula Kiadó, Budapest, 300 p. Hunyadi, L., Vita, L., 2008: Statisztikai képletek és táblázatok (oktatási segédlet).