Miller, Yost, Thompson, and Voight. (2024) Community Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania. The Journal of Plain Anabaptist Communities, Vol 4. No. 2.

We conducted a health needs assessment of three Plain communities in Lancaster County, Pennsylvania, from a random sample of 433 households surveyed by mail. Here we compare those findings with a similar survey we conducted in 2014–2015 with additional questions on vaccine uptake and the response to COVID-19. Results of the two surveys are quite similar. Plain respondents continue to have little diagnosed asthma, fewer mental health issues, and are more likely to have had prenatal care but otherwise their health is similar to that of other adults in Lancaster County.

Berwood A. Yost andJacqueline Redman (2023). The 2018 Pennsylvania Midterm Election

This article uses pre-election survey, post-election survey, voter registration, and election data to interpret the outcomes of the 2018 midterm elections for governor, U.S. Senate, and U.S. House of Representatives in Pennsylvania. This analysis shows that the results of the 2018 midterm races in Pennsylvania were nationalized. Feelings about the president’s performance drove voter interest and turnout, and also factored into the choices that voters made in the gubernatorial, U.S. Senate, and U.S. House races. Voter preferences in each race followed the same pattern: even after accounting for partisanship and ideology, those who were dissatisfied with President Trump’s performance were more likely to vote for a Democratic candidate. The results suggest that the 2018 midterm results were a repudiation of the Trump presidency, but not a return to the state’s pre-2016 politics.

Medvic, S.K. and Yost, B. A. (2022). Major PartyFactions in a Battleground State. In State of the Parties 2022: The ChangingRole of American Political Parties, David Cohen, John Green, and Kenneth Miller(eds.). Rowman & Littlefield.

The State of the Parties 2022 brings together leading scholars of parties, elections, and interest groups to provide an indispensable overview of American political parties today. The 2020 presidential election was extraordinary. What role did political parties play in these events? How did the party organizations fare? What are the implications for the future? Scholars and practitioners from throughout the United States explore the current state of American party organizations, constituencies and resources at the national, state and local level.

Kopko, K., Nolt, S., Redman, J., Yost, B. (2021). If You Play in the Mud, You Get Dirty: The Appropriation of Amish Group Identity during a Negative Campaign. The Journal of Plain Anabaptist Communities 1 (2): 42 – 56, DOI:

Using an original online experiment, we test whether the appropriation of Amish group identity influences voter behavior. We do not find that the appropriation of Amish group identity influences intended vote choice. However, there is evidence that associating the Amish with a candidate who was subjected to negative advertisements resulted in a reduction in approval rating for the Amish as a group. In addition, we find that the attitudes toward the Amish vary by respondent ideology and, consistent with the contact hypothesis, those individuals who interact regularly with the Amish reported more favorable ratings toward the Amish. The results raise important questions regarding the appropriation of a group's image in the course of a political campaign.

Yost, Berwood, Christina Abbott, Scottie Thompson Buckland, Mary Whitmoyer, and Kirk Miller. (2020). Psychological Stress and Birth Outcomes in Amish Women Before and After the Nickel Mines Shooting. Journal of Amish and Plain Anabaptist Studies8(1):75-84.

Objective: To evaluate the impact of the Nickel Mines shooting October 2, 2006 on the psychological stress and birth outcomes of Amish women living in proximity to the event. Methods: Data are from a population-based cohort study of 202 Amish women of childbearing age interviewed at baseline (winter 2004-2005) and 3 years later (winter 2007-2008). Data are also from Pennsylvania Department of Health birth records 2004-2008. Results: There was no apparent impact of the shooting on depression, social support, stress, number of diagnoses, sleep, doctor visits, number of medications, or anxiety. Nor was there an apparent impact on these outcomes when the distance of homes from the Nickel Mines school was taken into account. Timing of birth relative to the shooting apparently did not affect birthweight, gestation length or the probability of a low birthweight baby. Conclusions: Although the Nickel Mines shooting had a profound impact on the Amish community, we found no difference in Amish women's health, mental health, or birth outcomes when comparing pre and post shooting measures. This may reflect the very high levels of social support among these women

Yost, B., Redman, J. (Forthcoming). The 2018 Pennsylvania Midterm Election: No Escaping Trump. COMMONWEALTH: A Journal of Political Science.

This article uses pre-election survey data, post-election survey data, and voter registration and election data to interpret the outcomes of the 2018 midterm elections for Governor, US Senate, and Congress in Pennsylvania. This analysis shows that the results of the 2018 midterm races in Pennsylvania were nationalized; feelings about the President’s performance drove voter interest and turnout and also factored into the choices that voters made in the Gubernatorial, US Senate, and Congressional races. Voter preferences in each race followed the same pattern: even after accounting for partisanship and ideology, those who were dissatisfied with President Trump’s performance were more likely to vote for a Democratic candidate. The results suggest that the 2018 midterm results were a repudiation of the Trump Presidency, but not a return to the state’s pre-2016 politics.

Medvic, S.K. and Yost, B. A. (2019). An Endangered Republican Incumbent Survives in the Suburbs. In Cases in Congressional Campaigns: Split Decision, Randall Adkins and David Dulio (eds.). Routledge, NY.

A party on the wrong side of the momentum in a nationalized election will see a number of incumbents defeated who never appeared vulnerable, while a few vulnerable incumbents will withstand the tide. The general election campaign followed a common pattern for suburban districts in 2018: Democrats wanted to make President Donald J. Trump the focus of the race, while the Republicans tried to avoid any mention of the president. Scott Wallace relied heavily on his personal fortune to fund his campaign. While the Fitzpatrick campaign racked up endorsements from across the aisle, the Wallace campaign secured backing from only progressive and Democratic-leaning groups like the Sierra Club and MoveOn. Brian Fitzpatrick succeeded despite running down-ballot of uninspiring Republican US Senate and gubernatorial candidates in Pennsylvania. The campaign strategies used by the candidates coupled with the final results suggest the impressions that voters in Pennsylvania’s 1st Congressional District are likely to have formed about the two candidates.

Yost, B. A., Ciuk, D. (2019). Experimental Non-Compliance. In: Experimental Methods in Survey Research: Techniques that Combine Random Sampling with Random Assignment, Paul Lavrakas, Michael Traugott, Courtney Kennedy, Allyson Holbrook, Edith de Leeuw, and Brady West (eds.). John Wiley & Sons, NJ.

A thorough and comprehensive guide to the theoretical, practical, and methodological approaches used in survey experiments across disciplines such as political science, health sciences, sociology, economics, psychology, and marketing

Susan Dicklitch-Nelson, Scottie Thompson Buckland, Berwood Yost & Danel Draguljić (2019). From persecutors to protectors: Human rights and the F&M Global Barometer of Gay Rights TM (GBGR), Journal of Human Rights, DOI: 10.1080/14754835.2018.1563863

Sexual minorities are the most vulnerable minorities on the planet. Their existence challenges cultural norms, traditions, and power structures. They have been treated as social pariahs and scapegoats for the economic, political, or social ills in their countries. However, countries vary widely in the extent to which they are protective or repressive toward lesbian, gay, bisexual, and transgender individuals. This article systematically analyzes the global persecution and protection of sexual minorities through the application of the F&M Global Barometer of Gay RightsTM (GBGR). Using GBGR world data from 2011 to 2014, we document the variance in levels of state and societal persecution and protection of sexual minorities in 188 countries. Our findings suggest that having a higher life expectancy, a democratic system, a lower percentage of rural population, and lower religiosity are significant predictors of whether a country will be more rights-protective toward its sexual minorities.

Yost, B. A., Redman, J, Thompson, S. (2017). The 2016 Pennsylvania Presidential and US Senate Elections: Breaking Pennsylvania's Electoral Habits. COMMONWEALTH: A Journal of Political Science, 19 (2): 3 – 26.

This article uses pre-election survey data, post-election survey data, and voter registration and election data to interpret the outcomes of the 2016 presidential and U.S. Senate races in Pennsylvania. This analysis shows how changes in voter registration and voter turnout in specific areas of the Commonwealth, driven in large part by less-educated voters, those dissatisfied with the current direction of the country, and the performance of the incumbent president, explain the 2016 election results.

Miller, K., Yost, B., Abbott, C., Thompson, S., Dlugi, E., Adams, Z., Schulman, M., and Strauss, N. (2016). Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania. Journal of Community Health DOI: 10.1007/s10900-016-0223-5.

We performed a health needs assessment for five Plain communities in Pennsylvania from a random sample of households, comparing them to the general population of Pennsylvania adults. Plain respondents were more likely to drink well water, as likely to eat fruit and vegetables and much more likely to drink raw milk and be exposed to agricultural chemicals. Plain respondents were less likely to receive screening exams compared to the general population and there was variation from settlement to settlement in whether respondents had a regular doctor, whether they received preventive screenings or had their children vaccinated, with Mifflin County Amish generally lowest in these and Plain Mennonites highest. Plain respondents reported good physical and mental health compared to the general population but Groffdale Mennonite respondents had a high proportion of diagnoses of depression and were more likely to be receiving treatment for a mental health condition. Most Plain respondents would want a spouse tested for genetic disease with Mifflin County Amish least in favor of these tests. Despite their geographic and genetic isolation, the health of Plain communities in Pennsylvania is similar to that of other adults in the state.

Ciuk, D., Yost, B. (2015). The Effects of Issue Salience, Elite Influence, and Policy Content on Public Opinion. Political Communication DOI: 10.1080/10584609.2015.1017629.

When do citizens rely on party cues, and when do they incorporate policy-relevant information into their political attitudes? Recent research suggests that members of the public, when they possess some policy-relevant information, use that information as much as they use party cues when forming political attitudes. We aim to advance this research by specifying conditions that motivate people to use content over cues and vice versa. Specifically, we believe that increased issue salience motivates people to go beyond heuristics and engage in the systematic processing of policy-relevant information. Using data from a survey experiment that isolates the effects of policy-relevant information, party cues, and issue salience, we find that people are more likely to incorporate policy-relevant information when thinking about hydraulic fracturing (fracking), a relatively high-salience issue. When thinking about storm-water management, a relatively low-salience issue, people are more likely to rely on party cues.

Dicklitch, S., Yost, B., Dougan, B. (2012) Building a Better Barometer of Gay Rights (BGR): A Case Study of Uganda and the Persecution of Homosexuals. Human Rights Quarterly 34 (2): 448 - 471.

Few countries in the world actually embrace homosexuals as valuable members of their society and even fewer bestow full human rights on their homosexual citizens. The Barometer of Gay Rights (BGR) attempts to systematically quantify how rights protective and respective a country really is. This article will apply the BGR methodology to the Ugandan case study to measure the degree to which Uganda is an "active persecutor" of homosexuals. The BGR measures the constitutional protections afforded homosexuals, their civil, political, and socioeconomic rights, the presence and efficacy of gay rights organizations, and the degree of societal persecution.

Miller, K. and Yost, B.A. et al (2007). Health Status, Health Conditions, and Health Behaviors among Amish Women: Results from the Central Pennsylvania Women's Health Study. Women's Health Issues 17 (3): 162 – 171.

We performed one of the first systematic, population-based surveys of women in Amish culture. We used these data to examine health status and health risks in a representative sample of 288 Amish women ages 18–45 living in Lancaster County, Pennsylvania, in particular for risks associated with preterm and low birthweight infants, compared with a general population sample of 2,002 women in Central Pennsylvania. Compared with women in the general population, Amish women rated their physical health approximately at the same level, but reported less stress, fewer symptoms of depression, and had higher aggregate scores for mental health. Amish women reported low levels of intimate partner violence, high levels of social support, and they perceived low levels of unfair treatment owing to gender compared with the general population. Amish women also reported higher fertility, fewer low birthweight babies, but the same number of preterm births as the general population. The findings suggest that these outcomes may be due to higher levels of social support and better preconceptional behavior among Amish women.

Sims, B., Yost, B.A., Abbott, C.L. (2006) The efficacy of victim services programs: alleviating the psychological suffering of crime victims? Criminal Justice Policy Review 17 (4): 387 - 406.

With the movement of the victim to the forefront of the criminal justice system, more and more services have been developed to alleviate the pain and suffering caused by the victimization experience. Some services seek to alleviate the psychological suffering of crime victims and include such programs as crisis intervention, individual and group counseling, and so forth. Several studies have examined to what extent such programming can actually improve the psychological functioning of crime victims. The present study examines that question through a quasi-experimental design in which victims who used services and victims who did not use services participated in a statewide telephone survey. The major finding of the study adds to those of previous studies: There is no significant difference between service and nonservice users when it comes to improvement in the psychological functioning of crime victims.

Weisman CS, Hillemeier MM, Chase GA, Dyer AM, Baker SA, Feinberg M, Downs DS, Parrott RL, Cecil HK, Botti JJ, MacNeill C, Chuang CH, Yost B. (2006) "Preconceptional Health: Risks of Adverse Pregnancy Outcomes by Reproductive Life Stage in the Central Pennsylvania Women's Health Study (CePAWHS). Women's Health Issues 16(4):216-226.

This study used population-based data to examine how health status and risks vary by reproductive life stage, with particular focus on the proximal risks for preterm birth and low birthweight (LBW) infants in preconceptional and interconceptional women. Data are from the Central Pennsylvania Women's Health Study (CePAWHS), which included a telephone survey of a representative sample of 2,002 women ages 18-45 years residing in largely rural central Pennsylvania. Women were classified according to reproductive stage--preconceptional, interconceptional, and postconceptional--on the basis of pregnancy history and reproductive capacity. Multiple indicators of health status and health risks were examined by reproductive stage, stratified by age group (ages 18-34 and ages 35-45). Results show that many risk factors varied significantly by reproductive stage and by age group within reproductive stage. Preconceptional and interconceptional women exhibited several unhealthy behaviors (e.g., binge drinking, nutritional deficits, physical inactivity). Younger pre- and interconceptional women (ages 18-34) had more gynecologic infections, some less favorable health behaviors, and more psychosocial stress than older women (ages 35-45) in the same reproductive stages. Older preconceptional women were more likely to have chronic conditions (hypertension, high cholesterol) than younger preconceptional women. Results suggest how interventions could be tailored to women's reproductive stages.

Yost, B.A., Sims, B., Abbott, C.L. (2005). Use and Nonuse of Victim Services Programs: Implications from a Statewide Survey of Crime Victims. Criminology and Public Policy, Volume 4 (2): 361 – 384.

Research Summary: We explored the reasons for use and/or nonuse of victim services programs through a statewide survey of crime victims who did not use services, and a survey of clients of such programs in the Commonwealth of Pennsylvania. The survey instrument included questions about victim characteristics, the crime event, whether victims used services, victims' use of other social services, and individual coping mechanisms. Only type of crime and age were significant predictors of use of victim services programs, with older victims of violent crimes more likely to report using services than younger victims of nonviolent crimes. Policy Implications: Our findings mirror other studies that indicate very little usage of services by crime victims. Those who did not use services reported getting assistance from friends or family members, not being told about services, or not thinking it was worth the trouble to seek out such services. Also, victims demonstrated very little knowledge about the types of services provided by victim services programs. We conclude that a victim's decision not to seek assistance could be akin to the reason why so many crime victims never report their experience to the police in the first place. To increase the use of services by crime victims, a greater emphasis will need to be placed on educating the public about such services, adequately staffing programs with better trained individuals who can meet the needs of crime victims, and broadening the types of services provided to crime victims.

Yost, B.A. (2003). Disappearing Democrats: Rethinking Partisanship Within Pennsylvania's Electorate. Commonwealth, Volume 12: 77 – 86.

Pennsylvania contains many more registered Democrats than Republicans, but Pennsylvania Republicans control most of the statewide elected offices and both chambers of the state legislature. How is it possible that the Democrat’s registration advantage does not lead to more Democratic electoral successes? Using a random survey of Pennsylvania voters and comparative questions on party orientation and party registration, this study finds that many of the state’s voters identify with a political party that is different from the party in which they are actually registered. Party identification is important because it is a better predictor of voting behavior than party registration. The paper finds that more registered Democrats identify with the Republican Party than vice versa, making the Democrat’s registration advantage an advantage in name only.

Kozlowski, L.T., Vogler, G. P., Vandenbergh, D. J., Strasser, A. A., O'Connor, R. J., Yost, B. A. (2002). Using a telephone survey to acquire genetic and behavioral data related to cigarette smoking in 'made-anonymous' and 'registry' samples. American Journal of Epidemiology, Vol. 156, No. 1: 68-77.

In the Smokers and Nonsmokers Study, the authors investigated the feasibility of using random digit dialing telephone interviews to locate adults in the continental United States who were willing to provide DNA from buccal swabs through the mail. Interviews with 3,383 adults regarding their smoking-related behaviors (response rate = 70%) were conducted in 1999-2000; swab returns continued into early 2001. Overall, 57% of interviewees agreed to receive mailed information explaining the study. Better-educated persons (odds ratio (OR) = 1.3, 95% confidence interval (CI): 1.1, 1.6), younger persons (OR = 0.988, 95% CI: 0.983, 0.992), persons with symptoms of depression (OR = 1.8, 95% CI: 1.4, 2.4), and current smokers (OR = 2.25, 95% CI: 1.8, 2.8) were likelier to agree to receive a mailing. Approximately 26% of interviewees (45% of those receiving kits) returned buccal swabs, and 18% were successfully genotyped. Older (OR = 1.02, 95% CI: 1.01, 1.03), better-educated (OR = 1.4, 95% CI: 1.1, 1.7), and White (OR = 1.8, 95% CI: 1.4, 2.5) participants were more likely to return DNA samples, but current smokers (OR = 0.6, 95% CI: 0.5, 0.8) were less likely to do so. Participants were randomly assigned to one of two forms of participation: the "registry" group (names were kept on file) or the "made-anonymous" group (names were unassociated with samples). The two groups were equally likely to return kits, but registry respondents were more likely to nominate siblings for participation in the study (OR = 1.6, 95% CI: 1.2, 2.1). The participants in this study were similar demographically to the national population. The authors conclude that random digit dialing surveys coupled with mail collection of DNA may constitute a practical method of obtaining DNA samples for biobehavioral research.

Kozlowski, L.T., Palmer, R., Stine, M., Strasser, A., Yost, B. (2001) Persistent effects of a message counter-marketing light cigarettes: Results of a randomized controlled trial. Addictive Behaviors, Vol. 26: 447 - 452.

In a randomized, controlled trial, a national sample of smokers of Light cigarettes heard by telephone a "radio message" counter-marketing Light cigarettes. This message caused immediate changes in beliefs. Follow-up telephone interviews were done about 7 months later. The Message Group (N = 181) was more likely than the Control Group (N = 85) to report that (a) one Light equaled one Regular in tar yield to smokers, (b) Lights did not decrease health risks, and (c) they wanted to give up smoking (P less than .05) they did not report greater quitting or intention to quit, or greater knowledge of filter ventilation. Systematic counter-marketing of Lights is recommended. A telephone-based exposure and follow-up procedure could be a good way to study message effects.

Kozlowski, L.T., Yost, B.A., Stine, M. M., Celebucki, C. (2000) Massachusetts' Advertising Against Light Cigarettes Appears to Change Beliefs and Behavior. American Journal of Preventive Medicine, Vol. 18, No. 4: 339-342.

This study examined the effects of advertising directed against light cigarettes (lights). In a quasi-experimental post-test-only design, smokers and ex-smokers (

Kozlowski, L.T., Goldberg, M.E., Yost, B.A. (2000) Measuring Smokers' Perceptions of the Health Risks from Smoking Light Cigarettes. American Journal of Public Health, Vol. 90, No. 5.

Light cigarettes, the nation's bestsellers, help keep health-concerned smokers smoking.1–3 Studies of smokers'perceptions of light cigarettes4–7 found that 20% to 40% of smokers of light cigarettes believe these cigarettes reduce the risk of health problems.

Kozlowski, L.T., Goldberg, M.E., Sweeney, C.T., Palmer, R.F., Pillitteri, J.L., Yost, B.A., White, E.L., Stine, M.M. (1999) Smoker Reactions to a Radio Message that Light Cigarettes are as Dangerous as Regular Cigarettes. Nicotine & Tobacco Research, 1, 67-76.

The purpose of this study was to examine in a systematic, controlled fashion the reactions of smokers to scientifically correct information about the risks of smoking Light cigarettes (about 6-15 mg tar by the FTC method). Random-digit dialing, computer-assisted telephone interviews were used to locate daily smokers of Light cigarettes. In an experimental design, smokers were randomly assigned to listen (n = 293) or not (n = 275) to a persuasive simulated radio message on the risks of Light cigarettes; 108 of those who did not listen to the message in the first part of the interview were played the message in the second part, to evaluate some repeated-measures effects. Those who heard the message were more likely to report that one Light cigarette could give a smoker the same amount of tar as one Regular cigarette and that Light cigarettes were more dangerous: 55% said the message made them think more about quitting and 46% said the message increased the amount they wanted to quit; 42% said that after hearing the message they thought Light cigarettes were more dangerous. Using the Theory of Planned Behavior, structural equation modeling analysis indicated that the message acted to increase intention to quit smoking by increasing the desire to quit smoking. Seventy-three per cent of the smokers agreed that it was important to play such messages widely on the radio; 77% agreed that there should be a warning on packs that vent blocking increases tar; 61% agreed that the location of filter vents should be marked. The majority of smokers of Light cigarettes seem to value being informed that Light cigarettes are as dangerous for them as Regular cigarettes, and this information increases their intentions to quit smoking.

Kozlowski, L.T., White, E.L., Sweeney, C.T., Yost, B.A., Ahern, F.M., Goldberg, M.E. (1998) Few Smokers Know Their Cigarettes Have Filter Vents. American Journal of Public Health, Volume 88, Number 4.

"Few smokers know their cigarettes have filter vents.." American Journal of Public Health, 88(4), pp. 681–682

Kozlowski, L.T., Goldberg, M.E., Yost, B.A., White, E.L., Sweeney, C.T., and Pillitteri, J.L. (1998) Smokers' misperceptions of Light and Ultra-light cigarettes may keep them smoking. American Journal of Preventive Medicine, Volume 15, Number 1.

This study examined smokers' understanding of the relative tar deliveries of Ultra-light, Light, and Regular cigarettes, reasons for smoking Ultra-light/Light cigarettes, and the likelihood of both quitting smoking and switching to Regular cigarettes if they came to learn that one Ultra-light/Light cigarette gave the same amount of tar as one Regular cigarette. Ten- to fifteen-minute random-digit-dialed, computer-assisted telephone interviews (CATI) were conducted with both a national probability sample (n = 788) and a state random sample (n = 266) of daily smokers over the age of 18. Less than 10% of smokers in the national sample and only 14% of smokers in the state sample knew that one Light cigarette could give the same amount of tar as one Regular cigarette. Less than 10% of smokers in the state sample knew that one Ultra-light cigarette could give the same amount of tar as one Regular cigarette. Thirty-two percent of the Light and 26% of the Ultra-light smokers in the national sample, and 27% of Light and 25% of Ultra-light smokers in the state sample, said they would be likely to quit smoking if they learned one Light/Ultra-light equaled one Regular. Many Light and Ultra-light smokers are smoking these cigarettes to reduce the risks of smoking and/or as a step toward quitting. However, these smokers are unaware that one Ultra-light/Light cigarette can give them the same amount of tar and nicotine as one Regular cigarette. Many of the Ultra-light/Light smokers sampled in this study stated that they would be likely to quit if they knew this information. Mistaken beliefs about low-yield brands are reducing intentions to quit smoking.

Kozlowski, L.T., Pillitteri, J.L, Yost, B.A., Goldberg, M.E., & Ahern, F.M. (1998). Advertising fails to inform smokers of official tar yields of cigarettes. Journal of Applied Biobehavioral Research, 3, 1, 55-64.

In the United States, cigarette advertising reports standard tar and nicotine yields, following a voluntary agreement between the Federal Trade Commission (FTC) and cigarette manufacturers. National probability samples of smokers of ultra-light (N = 218), light (N = 360), and regular (N = 210) cigarettes were asked in telephone interviews to indicate the tar yield of their cigarettes, as well as where to find information on tar yield. Only 13% of ultra-light smokers, 2% of light smokers, and 1% of regular smokers knew the correct tar yield of their brand, and few in each brand category reported that they would look for tar yields in advertisements. If the FTC testing system is revised and improved, smokers may well not learn about the changes, given that (a) the advertising-based system fails to inform them and (b) smokers' awareness of tar yields seems to be based on unregulated and misleading terms such as"ultra-light" and "light."

Kozlowski, L.T., Goldberg, M.E., Yost, B.A., Ahern, F.M., Aronson, K.R., & Sweeney, C.T. (1996) Smokers are unaware of the filter vents now on most cigarettes: Results of a national survey. Tobacco Control, 5, 265-270.

To evaluate awareness and knowledge of cigarette filter ventilation in a national probability sample of smokers of Ultra-light, Light, and regular cigarettes. Random-digit-dialling and computer-assisted telephone interviewing was used on a probability sample of daily cigarette smokers (ages 18 and above). 218 Smokers of Ultra-light cigarettes, 360 smokers of Light cigarettes, and 210 smokers of Regular cigarettes living in the continental United States. Percentage of respondents indicating knowledge of the presence of filter vents and the consequences of behavioural blocking of vents. Many smokers had not heard about or seen the filter holes: 43% (95% CI = 36 to 50%) of smokers of Ultra-lights, 39% (95% CI = 34 to 44%) of smokers of Lights, and 47% (95% CI = 40 to 54%) of smokers of Regulars. About two in three smokers either did not know of the existence of rings of small holes on the filters of some cigarettes, or did not know that blocking increases tar yields: 69% (95% CI = 63 to 75%) of Ultra-lights, 66% (95% CI = 61 to 71%) of Lights, and 69% (95% CI = 63 to 75%) of Regulars. Smokers are generally unaware of the presence and function of filter vents-a major design feature subject to behavioural blocking by smokers and now present on most cigarettes in the United States. Smokers and policy-makers need to be informed about the presence of filter vents and how vent blocking increases tar and nicotine yields from ostensibly very low-yield cigarettes.