Which of the following hypotheses are indicative of an experimental research design?

The choice indicating that "the incidence of urinary tract infections will be greater in patients whose Foley catheters are irrigated frequently than those whose Foley catheters are irrigated less frequently" reflects the characteristics of an experimental research design because it establishes a clear cause-and-effect relationship. It specifically compares two groups based on a manipulated variable (frequency of irrigation) and measures the outcome (incidence of urinary tract infections) to determine if there is a significant difference between them.

Experimental research is defined by having an independent variable that is manipulated to observe its effect on a dependent variable, often involving random assignment to control and experimental groups. This option makes a strong predictive statement which showcases the expectation of a direct impact of the treatment (irrigation frequency) on the outcome (urinary tract infections), aligning well with the essence of experimental design.

In contrast, the other options either imply associations or correlations, rather than direct manipulation and causation. The first choice suggests a relationship but does not imply a comparison between groups induced by a controlled manipulation. The third option frames it as an association, lacking the direct comparative aspect needed for an experimental study. Lastly, the fourth option is more about establishing a null hypothesis, which is also not indicative of an experimental design since