Experimental Design in Research

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Questions and Answers

What is the primary purpose of an experimental design?

To establish a scientific theory

To define variables and assign subjects

To create controlled conditions for an experiment to limit outside interference (correct)

To create a hypothesis

What is the relationship between the independent and dependent variables in an experiment?

The dependent variable is manipulated, and the independent variable is measured

They have no relationship with each other

They are interchangeable terms

The independent variable is manipulated, and the dependent variable changes as a result (correct)

What is the main difference between a scientific theory and a scientific law?

A scientific theory is a pattern, while a scientific law is an explanation

A scientific theory is a proven fact, while a scientific law is a hypothesis

A scientific theory is a hypothesis, while a scientific law is a proven fact

A scientific law is a pattern, while a scientific theory is an explanation (correct)

What is the importance of using proper equipment in an experiment?

It ensures that the measurements are accurate and precise Signup and view all the answers

What is the ultimate goal of conducting an experiment through an experimental design?

To form a conclusion based on the hypothesis Signup and view all the answers

What is the purpose of the dependent variable in an experiment?

To measure the effect of the independent variable on the outcome Signup and view all the answers

What was the purpose of the placebo group in the pharmaceutical company's experiment?

To act as a control group and compare with the treatment group Signup and view all the answers

What is the role of the experimenter in an experiment?

To conduct the experiment under the same conditions and only change the independent variable Signup and view all the answers

What type of data were collected in the plant experiment?

Both quantitative and qualitative data Signup and view all the answers

What is the first step in creating a good experiment for science?

Having knowledge of the topic Signup and view all the answers

What is the primary reason for conducting an experiment through the scientific method?

To allow others to repeat the process and accept or reject the results Signup and view all the answers

What is the purpose of a hypothesis in the experimental design process?

To make an educated guess about the outcome of the experiment Signup and view all the answers

What is the difference between the independent variable and the dependent variable in an experiment?

The independent variable is the factor being changed, and the dependent variable is the factor being measured Signup and view all the answers

What is the role of the control group in an experiment?

To remain under normal unchanged conditions Signup and view all the answers

What is the purpose of random assignment in an experiment?

To randomly assign subjects to either the experimental or control groups Signup and view all the answers

Study Notes

Experimental Design

Experimental design is a method to test a hypothesis through a series of steps, creating controlled conditions to limit outside interference.
The purpose is to form a conclusion based on the hypothesis, which can lead to supporting evidence of scientific law and theory.

Variables

Independent variable: manipulated in an experiment, causing a change in the dependent variable.
Dependent variable: changes as an effect of the independent variable being changed.
Control variable: remains unchanged, providing a baseline for comparison.

Scientific Theory and Law

Scientific theory: explains why things occur the way they do, supported by evidence from repeated experiments.
Scientific law: a pattern, typically established through an equation, supported by data from repeated experiments.

What Makes a Good Experiment

A good experiment requires background knowledge, proper equipment, and attention to accuracy and precision.
Accuracy: how close values collected are to the real value.
Precision: how close all measurements are to one another.

Experimental Design Process

Step 1: Define Variables - identify independent, dependent, and control variables.
Step 2: Formulate a Hypothesis - make an educated guess about the experiment's outcome.
Step 3: Experimental Design - create a treatment group and a control group.
Step 4: Assign Subjects - randomly select and assign subjects to groups.
Step 5: Measure the Dependent Variable - collect data and analyze results.

Example of an Experimental Investigation

Pharmaceutical company conducts an experiment to test a medication's effectiveness.
Two groups: treatment group receives the medication, placebo group receives a dummy pill.
Data collected shows positive results for patients in the treatment group, confirming the medication's effectiveness.

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Description

Learn about the fundamentals of experimental design, including the relationships between independent and dependent variables, and how to test a hypothesis.