5. Smokers for whom the investigators cannot definitively quantify an outcome with respect to continuous abstinence will be excluded from all analyses and replaced. Any report of smoking during the two-week cessation period (reported either during the 4x daily web surveys or the laboratory visit at 2 weeks) is sufficient to code the smoker to have lapsed (i.e., not continuously abstinent), even if the participants do not complete the full two weeks of web surveys and/or the 2-week laboratory visit. However, the status of smokers who report no smoking during the cessation attempt but have both a high level of missing data from the web surveys (> 25% of reports) and no two-week laboratory visit report will be deemed uncertain. These smokers will be excluded and replaced.