A comparison of two methods for assessing awareness of antitobacco television advertisements.

BACKGROUND: This study uses an online survey panel to compare two approaches for assessing ad awareness. The first uses a screenshot of a television ad and the second shows participants a full-length video of the ad. METHODS: We randomly assigned 1034 Minnesota respondents to view a screenshot or a streaming video from two antitobacco ads. The study used one ad from ClearWay Minnesota's ITALIC! We All Pay the Price campaign, and one from the Centers for Disease Control ITALIC! Tips campaign. The key measure used to assess ad awareness was aided ad recall. Multivariate analyses of recall with cessation behaviour and attitudinal beliefs assessed the validity of these approaches. RESULTS: The respondents who saw the video reported significantly higher recall than those who saw the screenshot. Associations of recall with cessation behaviour and attitudinal beliefs were stronger and in the anticipated direction using the screenshot method. Over 20% of the respondents assigned to the video group could not see the ad. People who were under 45 years old, had incomes greater than $35,000 and women were reportedly less able to access the video. CONCLUSIONS: The methodology used to assess recall matters. Campaigns may exaggerate the successes or failures of their media campaigns, depending on the approach they employ and how they compare it to other media campaign evaluations. When incorporating streaming video, researchers should consider accessibility and report possible response bias. Researchers should fully define the measures they use, specify any viewing accessibility issues, and make ad comparisons only when using comparable methods.

Linking community and ecosystem development on Mount St. Helens.

In the two decades following the 1980 eruption of Mount St. Helens in Washington State, the N2-fixing colonizer Lupinus lepidus is associated with striking heterogeneity in plant community and soil development. We report on differences in nutrient availability and plant tissue chemistry between older, dense patches (core) of L. lepidus and more recently established low density patches (edge). In addition, we conducted a factorial nitrogen and phosphorus fertilization experiment in core patches to examine the degree of N and P limitation in early primary succession. We found that there were no significant differences in N or P availability between core and edge L. lepidus patches during the dry summer months, although nutrient availability is very low across the landscape. In the high density patches we found lower tissue N content and higher fiber content in L. lepidus tissue than in the younger edge patches. The addition of nutrients substantially altered plant community composition, with N addition causing an increase in other forb biomass and a corresponding competition-induced decline in L. lepidus biomass. The majority of the positive biomass response came from Hypochaeris radicata. In the second year of the fertilization experiment, the addition of N significantly increased total community biomass while L. lepidus biomass declined by more than 50%. The response of every species other than L. lepidus to N additions suggests that N may be the macronutrient most limiting plant production on Mount St. Helens but that the gains in productivity were somewhat offset by a decline of the dominant species. By the third year of the experiment, L. lepidus began to increase in abundance with P addition. This result suggests co-limitation of the community by N and P.