Paying for First Dates USA Today posted this question on the electronic version of its newspaper: “Should guys pay for the first date?” Of the 1148 subjects who decided to respond, 85% of them said “yes.”


c. Does the survey constitute an experiment or an observational study?

Verified step by step guidance

1. Understand the definitions: An experiment involves manipulating one or more variables to determine their effect on a response variable, while an observational study involves observing subjects without manipulation.
2. Identify the key elements of the survey: The survey asked a question and recorded responses without manipulating any variables.
3. Determine if there was any manipulation: In this case, the survey simply collected opinions without altering any conditions or variables.
4. Recognize the nature of the data collection: Since the survey collected responses based on participants' existing opinions, it aligns with the characteristics of an observational study.
5. Conclude the type of study: Based on the lack of manipulation and the method of data collection, this survey is an observational study.

Key Concepts

Experiment vs. Observational Study

An experiment involves manipulating one or more variables to observe the effect on another variable, often with random assignment to treatment groups. In contrast, an observational study involves observing subjects without manipulating any variables, simply recording data as it naturally occurs. Determining whether a study is experimental or observational is crucial for understanding the nature of the conclusions that can be drawn.

Sampling Bias

Sampling bias occurs when the sample collected is not representative of the population intended to be analyzed, often due to non-random selection methods. In the context of surveys, voluntary response bias is a common form of sampling bias, where individuals self-select to participate, potentially skewing results. Recognizing sampling bias is essential for evaluating the reliability and validity of survey findings.

Voluntary Response Sample

A voluntary response sample is a type of non-probability sampling where participants choose to be part of the sample. This method often leads to biased results because those who feel strongly about the topic are more likely to respond, which may not reflect the views of the general population. Understanding this concept helps in assessing the limitations of survey data and the generalizability of its conclusions.