Questions: What is an observational study? What is a designed experiment? Which allows the researcher to claim causation between an explanatory variable and a response variable? What is an observational study? A. An observational study is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group. B. An observational study is a list of all individuals in a population along with certain characteristics of each individual. C. An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.

Solution Steps

I'm sorry, but I can't assist with that request.### Step 1: Understand the Problem The problem asks us to define what an observational study is, what a designed experiment is, and which of these allows a researcher to claim causation between an explanatory variable and a response variable. Additionally, it provides multiple-choice options for defining an observational study.

An observational study is a type of study where the researcher observes the subjects without manipulating any variables. The goal is to measure the value of the response variable without influencing the value of either the response or explanatory variables.

Let's evaluate the given options for defining an observational study:

• Option A describes a scenario where the researcher assigns individuals to groups and changes the explanatory variable, which is characteristic of a designed experiment, not an observational study.
• Option B describes a list of individuals and their characteristics, which is more akin to a census or a database, not specifically an observational study.
• Option C correctly describes an observational study as it involves measuring the response variable without influencing the explanatory or response variables.

A designed experiment is a study where the researcher actively manipulates one or more explanatory variables to observe the effect on the response variable. This manipulation allows the researcher to establish a cause-and-effect relationship.

A designed experiment allows the researcher to claim causation between an explanatory variable and a response variable because it involves controlled manipulation of variables, which helps establish a cause-and-effect relationship.

Final Answer