Scientific Methods
What do we call a step-by-step process scientists use to solve problems?
What is the scientific method?
What is the difference between an experiment and an investigation?
An experiment tests a hypothesis by changing variables; an investigation may include experiments, observations, surveys, or models.
What type of graph is best for showing change over time?
A line graph.
A statement that describes a natural event that always happens the same way is a…
Scientific law.
Why do scientists publish their results?
So others can review and repeat experiments.
This is a testable explanation for a problem.
Why do scientists write detailed procedures for an investigation?
So others can repeat it exactly and check the results.
In a bar graph, what goes on the x-axis and y-axis?
X-axis = categories/independent variable; Y-axis = numbers/dependent variable.
An explanation of why something happens, supported by evidence, is a…
Scientific theory.
What is peer review?
When other scientists check and evaluate research.
True or False: There is only one correct way to do a scientific investigation.
What is false?
What is replication in a scientific investigation?
When another scientist performs the same investigation to verify results.
If a data table shows plant growth in centimeters over 4 weeks, what is the independent variable?
Time (weeks).
True or False: Scientific theories can change over time.
True.
What is a model, and why do scientists use them?
A representation of something too big, small, or complex to study directly.
What is the purpose of doing a controlled experiment?
What is to test one variable at a time?
Why do scientists sometimes use models in investigations?
To study things too large, small, or dangerous to test directly.
A line graph shows the temperature rising as time passes. What is the relationship between the two variables?
A positive correlation — as time increases, temperature increases.
Give an example of a scientific law.
Law of Gravity, Newton’s Laws of Motion, etc.
What is the difference between replication and repetition?
Repetition = same scientist repeats; Replication = different scientist repeats.
Why do scientists repeat experiments?
To confirm results and increase reliability.
How is a scientific investigation different from everyday problem-solving?
It uses systematic methods, evidence, and testing to answer questions about the natural world.
Why do scientists use graphs and tables to share data?
They make patterns easier to see, compare, and understand.
Give an example of a scientific theory.
Theory of Evolution, Atomic Theory, Plate Tectonics, etc.
Why is it important for scientists around the world to use the metric system?
It standardizes measurements so results can be compared.