A researcher is studying the relationship between speed of cycling and the presence of people. Formulate a relevant hypothesis and identify the independent and dependent variables.
A relevant hypothesis for this study would be: "The presence of people has an effect on the speed of cycling." This statement predicts the causal relationship the researcher intends to examine.
The independent variable is the variable that is manipulated or altered by the researcher. In this study, the independent variable is the presence of people. The researcher would vary this condition (e.g., presence vs. absence) to observe its impact.
The dependent variable is the variable on which the effect of the independent variable is observed. It represents the phenomenon the researcher desires to explain. In this case, the dependent variable is the speed of cycling, which is expected to change based on the presence of people.
Explanation
The answer applies the definitions provided in the textbook context. The context defines the independent variable as the one manipulated by the researcher (similar to the 'presence or absence of other persons' in the Latane and Darley example) and the dependent variable as the phenomenon to be explained or observed (similar to 'frequency of reporting'). Therefore, 'presence of people' is the cause (independent variable) and 'speed of cycling' is the effect (dependent variable).