11 research outputs found
Modeling the Clickstream: Implications for Web-Based Advertising Efforts
In this paper, we develop an analytical approach to modeling consumer response to banner ad exposures at a sponsored content Web site that reveals significant heterogeneity in (unobservable) click proneness across consumers. The effect of repeated exposures to banner ads is negative and nonlinear, and the differential effect of each successive ad exposure is initially negative, though nonlinear, and levels off at higher levels of passive ad exposures. Further, significant correlations between session and consumer click proneness and banner exposure sensitivity suggest gains from repeated banner exposures when consumers are less click prone. For a particular number of sessions, more clicks are generated from consumers who revisit over a longer period of time, than for those with the same number of sessions in a relatively shorter timeframe. We also find that consumers are equally likely to click on banner ads placed early or late in navigation path and that exposures have a positive cumulative effect in inducing click-through in future sessions. Our results have implications for online advertising response measurement and dynamic ad placement, and may help guide advertising media placement decisions.Advertising and Media Research, Clickstream Data, Computer-Mediated Environments, Online Consumer Behavior, Random-Coefficient Models, Internet, World Wide Web
Evaluating the power of surface attendance counts to detect long-term trends in populations of crevice-nesting auklets
Power analyses are essential when developing a long-term monitoring program for a target species whose observation is logistically challenging and expensive. These analyses can be complicated when the observations have a complex variance structure reflecting many factors. Crevice-nesting seabirds such as least and crested auklets Aethia pusilla and Aethia cristatella illustrate both this need and these challenges. They are ecosystem indicators for the Bering Sea, a system expected to undergo large changes. Unfortunately, they are difficult to monitor as colonies occur on remote, hard to access islands in the Aleutians and Bering Sea, and nests occur in crevices underground, preventing direct observation. Current monitoring consists of breeding-season counts of auklets standing on the surface of sample plots in the colony; logically, a substantial decline in nesting population guarantees an eventual substantial decline in surface attendants. Yet, it remains debatable whether these highly variable counts can be used to statistically detect biologically relevant declines in the attending population let alone the nesting population. Subsequently, existing monitoring programs vary widely in survey design, effort levels, and daily summary statistics. The power of different survey designs was assessed by simulating observations from a state model developed from 11 years of observations using mixed-effects models and zero-inflated Poisson-lognormal regression. The analyses illustrate the process required for any monitoring program whose observations are described inadequately by standard statistical models. State model development revealed survey design refinements that reduce sampling variation. For least auklets, current sampling efforts provided 90% power to detect annual declines of 11% ("Critically Endangered" using IUCN Red List criteria), 4.5% ("Endangered"), or 2.4% ("Vulnerable") in two, four, or six generations, respectively; crested auklets took a few years longer. Power was more sensitive to number of days than number of plots. Results appear robust across a range of bird densities, providing guidance for monitoring other colonies or crevice-nesting species with similar life history strategies. Research should now focus on illuminating the relationship between the attending and nesting populations. Given the frequency of complicated variance structures and zero counts in ecological data, the general statistical models used here should prove widely applicable.</p
Explaining age-related differences in depression following breast cancer diagnosis and treatment
Age-related longitudinal changes in depressive symptoms following breast cancer diagnosis and treatment
Large-Scale Identification of Core-Fucosylated Glycopeptide Sites in Pancreatic Cancer Serum Using Mass Spectrometry
The Role of Religion and Spirituality in the Association Between Hope and Anxiety in a Sample of Latino Youth
A Longitudinal Investigation of Posttraumatic Growth in Adult Patients Undergoing Treatment for Acute Leukemia
History of the Book in Canada. Volume III : 1918-1980
"The History of the Book in Canada is one of this country's great scholarly achievements, with three volumes spanning topics from Aboriginal communication systems established prior to European contact to the arrival of multinational publishing companies. Each volume observes developments in the realms of writing, publishing, dissemination, and reading, illustrating the process of a fledgling nation coming into its own. The third and final volume follows book history and print culture from the end of the First World War to 1980, discussing the influences on them of the twentieth century, including the country's growing demographic complexity and the rise of multiculturalism." -- Front flap of jacket