Final answer:
The research by Strassberg and Holty is an example of an experimental design as it involves manipulating an independent variable (the content of personal ads) to determine the effect on a dependent variable (responses to the ads).
Step-by-step explanation:
The study described by Strassberg and Holty (2003) that compared responses to women's internet personal ads by presenting participants with an ad focusing on different characteristics is an example of a b. Experimental design. This is because in an experimental design, the research would involve manipulating an independent variable to determine its effect on a dependent variable and measure outcomes. The presentation of different ads focuses on varying characteristics that attempt to manipulate the response variable, thereby fitting the criteria for an experiment rather than a simple observational study.
In contrast, an observational study would entail observing and recording events or characteristics without manipulating any variables. Researchers conducting an observational study gather data on naturally occurring variables without intervention. If the study in question had simply measured responses without changing any variables, it would have been considered observational.