A social intervention: The 1955 Connecticut crackdown on speeding In 1955, a record 324 persons were killed in automobile accidents on Connecticut highways.

Slides:



Advertisements
Similar presentations
Defining Characteristics
Advertisements

Evaluation Research Pierre-Auguste Renoir: Le Grenouillere, 1869.
CHAPTER 12, evaluation research
Chapter 4: Designing Studies
Copyright © 2010, 2007, 2004 Pearson Education, Inc. Chapter 13 Experiments and Observational Studies.
Correlation AND EXPERIMENTAL DESIGN
Research Design and Validity Threats
Extension Article by Dr Tim Kenny
Non-Experimental designs: Developmental designs & Small-N designs
Chapter 51 Experiments, Good and Bad. Chapter 52 Experimentation u An experiment is the process of subjecting experimental units to treatments and observing.
Evaluation Research COMT 502. topics Evaluation research –Process of determining whether intervention has its intended result.
Quasi-Experimental Designs Whenever it is not possible to establish cause-and-effect relations because there is not complete control over the variables.
Experiments Pierre-Auguste Renoir: Barges on the Seine, 1869.
The Study of Adult Development and Aging:
Experiments and Observational Studies.  A study at a high school in California compared academic performance of music students with that of non-music.
Drunk Driving I'm against drunk driving because there are many accidents each year that r caused by drinking and driving.
PILOT STUDY. Pilot study is a small scale preliminary study conducted in order to evaluate feasibility, time, cost, adverse events, and effect size (Statistical.
Experimental and Quasi- Experimental Designs Chapters 9 & 10.
Copyright © 2010 Pearson Education, Inc. Chapter 13 Experiments and Observational Studies.
Experiments and Observational Studies. Observational Studies In an observational study, researchers don’t assign choices; they simply observe them. look.
Chapter 13 Notes Observational Studies and Experimental Design
Chapter 13 Observational Studies & Experimental Design.
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Chapter 13 Experiments and Observational Studies.
Chapter 8 Measuring Chapter 81. Measurement We measure a property of a person or thing when we assign a number to represent the property. We often use.
DEFENSIVE DRIVING TRAINING. What's difficult about driving? Increasing amount of vehicles on the road Other drivers attitudes Weather conditions Heavy.
Slide 13-1 Copyright © 2004 Pearson Education, Inc.
Evaluating a Research Report
Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy.
1 Experimental Research Cause + Effect Manipulation Control.
The Practice of Statistics, 5th Edition Starnes, Tabor, Yates, Moore Bedford Freeman Worth Publishers CHAPTER 4 Designing Studies 4.2Experiments.
AP STATISTICS LESSON AP STATISTICS LESSON DESIGNING DATA.
28 April Crawford School 1 Causality and Causal Inference Semester 1, 2009 POGO8096/8196: Research Methods Crawford School of Economics and Government.
McMillan Educational Research: Fundamentals for the Consumer, 6e © 2012 Pearson Education, Inc. All rights reserved. Educational Research: Fundamentals.
Africa Impact Evaluation Program on AIDS (AIM-AIDS) Cape Town, South Africa March 8 – 13, Steps in Implementing an Impact Evaluation Nandini Krishnan.
Practice- Based Evaluation Research Week 4 Day 2 DIE 4564 Research Methods.
The Practice of Statistics, 5th Edition Starnes, Tabor, Yates, Moore Bedford Freeman Worth Publishers CHAPTER 4 Designing Studies 4.2Experiments.
DEFENSIVE DRIVING TRAINING What's difficult about driving? Increasing amount of vehicles on the road Other drivers attitudes Weather conditions Heavy.
Political Science 30 Political Inquiry Quasi-Experiments: Good Enough for Social Science.
Experiments Textbook 4.2. Observational Study vs. Experiment Observational Studies observes individuals and measures variables of interest, but does not.
Copyright © 2009 Pearson Education, Inc. Chapter 13 Experiments and Observational Studies.
Drinking and Driving A Preventable Tragedy.
CHAPTER 4 Designing Studies
CHAPTER 4 Designing Studies
Quasi-Experiments: Good Enough for Social Science
Experiments and Observational Studies
Observational Studies and Experiments
Experiments and Observational Studies
CHAPTER 4 Designing Studies
Chapter 4: Designing Studies
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
Lesson Using Studies Wisely.
Statistical Reasoning December 8, 2015 Chapter 6.2
Chapter 5: Producing Data
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
CHAPTER 4 Designing Studies
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
CHAPTER 4 Designing Studies
Chapter 4: Designing Studies
Chapter 4: Designing Studies
Chapter 4: Designing Studies
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
Chapter 4: Designing Studies
Chapter 4: Designing Studies
CHAPTER 4 Designing Studies
Presentation transcript:

A social intervention: The 1955 Connecticut crackdown on speeding In 1955, a record 324 persons were killed in automobile accidents on Connecticut highways. On December , Governor Ribicoff announced a crackdown on speeders. –first speeding offense: 30 day license suspension. –third offense: 1-year suspension. In 1956, the number of fatalities dropped to 284. –“Connecticut has succeeded in stopping the upward surge in highway deaths, and … contrary to the national trend, we have saved lives. Fewer people died on the highways this year than in the same period last year, in Connecticut. We did it by enforcing the law, something the safety experts said couldn’t be done because the people wouldn’t be behind it.”

Topics appropriate for evaluation research Evaluation research: research to find the impact of some social intervention, such as a program aimed at solving a problem. –Connecticut crackdown on speeding –education initiatives, welfare reform, etc. Common comparisons used in evaluation research. –some experience the treatment, some don’t (by some level of nonrandom assignment). –before-and-after testing

Issues of measurement in evaluation research (1) Issues related to populations of interest: –It can be difficult to identify the population of interest (example: effects of state welfare laws on state-to-state migration). Issues related to outcomes: –sometimes the desired outcome is difficult to measure (how much people think about exposure to AIDS) often, the outcome that can be measured is not a clear social good in itself –sometimes the desired outcome (such as a reduction in traffic deaths) has other causes –the scale used to measure the outcome can affect the result (traffic deaths versus traffic death rates)

Issues of measurement in evaluation research (2) Issues related to independent (i.e., explanatory) variables – also called interventions: –The timing of an intervention may be unclear. Issues related to contextual or mediating variables: –it is often critical to identify and measure such variables in order to make a compelling case.

Research designs in evaluation research Fully experimental (researcher sets the level of all independent variables – best but almost never happens) Quasi-experimental –time series (before and after) –non-equivalent control groups Qualitative evaluations –whenever possible, one should support quantitative results with qualitative evaluations (by what mechanisms is a crackdown on speeding expected to lower fatality?)

Major concerns in time-series analysis (1) Time series analysis is usually the most effective form of evaluation research, but it presents several key difficulties. History: anything that happens at the same time as the intervention could be the cause of the measured outcome –examples for 1955: bad weather in Connecticut, increased traffic congestion, changes in automobile design. Instability: rates tend to go up and down anyway. –an intervention imposed after an all-time high will tend to be followed by a decline even if chance alone is the only cause (i.e., sampling variation).

Major concerns in time-series analysis (2) Testing: The first measurement of the phenomenon can affect the second measurement in ways unrelated to the intervention. –For example, media exposure of traffic fatalities might convince people to drive more carefully. Instrumentation and measurement: the increased concern that leads to a social intervention can also lead to more careful screening for the outcome. –For example, a nationwide campaign to urge people to quit smoking to prevent heart disease could lead to an increase in reports of heart disease caused by smoking.

Major concerns in time-series analysis (3) Diffusion: the crackdown in Connecticut might well have reduced traffic speed and fatalities in neighboring states.

Other issues in evaluation research Motivation: respondents, enforcers, or administrators often do not cooperate with the program or with attempts to gather data. –examples: school administrators and teachers for No Child Left Behind or judges who thought the Connecticut crackdown was excessive. Results are often ignored or attacked by interested parties. There are many ethical concerns as well –who should be assigned to treatments? –is it ethical to gather the information?

Steps in an evaluation of the Connecticut crackdown on speeding, 1955 – 1956.

Speeding violations as a percent of all traffic violations decreased (seems to suggest motorists took the crackdown seriously), but the penalties for those arrested were higher than before the crackdown.

Note the increase in the percentage of arrests for driving with a suspended license as a percentage of all suspensions (i.e., probably more people drove illegally). Also note that judges may have felt the crackdown was too severe (i.e., the increase in not guilty verdicts).

While we can’t be absolutely sure, the crackdown probably reduced traffic fatalities. Rates seemed to decline more in Connecticut than surrounding states (however - Rhode Island similar). Nevertheless, the crackdown may not have been the best use of state money (i.e., opportunity costs).