Nature of Science and The Scientific Method Ms Clark PVMHS

What is Nature of Science? Science is about understanding how nature and the physical world work. It is the union of science, mathematics, and technology that forms the scientific endeavor. Science assumes that the things and events in the universe occur in consistent patterns that can be understood through careful, systematic study Science assumes that the universe is, a vast single system in which the basic rules are the same everywhere. Science is a process for producing knowledge. Scientists accept some uncertainty as part of nature, theories may change but most scientific knowledge is durable.

6 tenets of NOS Scientific knowledge is durable but tentative Scientific activity requires both being logical & systematic as well as creative& imaginative Science can be subjective and biased because of social, historical, and cultural influences Science and its methods cannot answer all questions There is no such thing as a single “scientific method” Scientific knowledge is a product of both observation and inference

Bias Bias is a personal judgment based on past experiences or personal beliefs Objective: not influenced by prejudices, opinion, feelings or interests Unbiased Subjective: influenced by prejudices, opinion, feelings or interests Biased

“The Scientific Method” i.e. the scientific process generalized Make an observation Ask a question Gather information Form an hypothesis Conduct an experiment Collect, record, and analyze data Draw a conclusion Report results & retest

Observations Types of observations: Quantitative: numbers Are gathered through your senses Types of observations: Quantitative: numbers Ex: 5 rabbits Qualitative: descriptions Ex: The rabbits have long ears

What’s wrong with my plant? Ask a question After making an observation, question what caused the effect. Can also be something another researcher did that left you with questions. What’s wrong with my plant?

Write a hypothesis This becomes your hypothesis statement. A hypothesis must be testable and predict an outcome. Formulate your hypothesis and write it down. A hypothesis is an educated guess Then make a prediction based your hypothesis using an “if….., then…..” This becomes your hypothesis statement. Example: Hypothesis – I think watering my plant will cause it to perk up. Hypothesis statement – If my plant receives water, then it will perk up. Teach kids to write own def

Test your hypothesis Design an experiment that will test whether your hypothesis is correct or not. A good experiment will only test one variable at a time – this is known as a controlled experiment. Variable – The factor that is being measured in the experiment. Relate to hypothesis in previous slide. Deconstruct the hypothesis. Do this on the board!

The Control A control is what we keep the same so it will not effect the outcome. A control is not tested. Controls are used for comparison and allow us to accept or reject a hypothesis. Relate to hypothesis in previous slide. Deconstruct the hypothesis. Do this on the board! 10

Variables independent variable: what you change. dependent variable: what you observe. control: what you keep the same Relate to hypothesis in previous slide. Deconstruct the hypothesis. Do this on the board! 11

Let’s practice…. Suppose you want to figure out if watering your plant will cause it to perk up and look healthy again. You will give it water, but keep all other conditions the same (sun, room temp, fertilizer, humidity, etc.). You will then make more observations to confirm/reject your hypothesis. 12

What are the Variables in Your Experiment? Independent variable: What you change… The water Dependent variable: What is being measured Turgidity of the stem Control Variable: What stays the same Amount of sun, room, temp, humidity, etc. 13

Data Collection After setting up & running your experiment, you collect data. What is data? The dependent variable vs. the independent variable. Researchers collect data from several trials for validity. Minimum of 3 per independent variable

Analyze Data Examine the data for trends. Create graphs or charts to show data easily. Accept or reject hypothesis based on the data. Next: Collaborate with peers, rethink experiment and hypothesis 15

Draw Conclusions Accept or reject hypothesis Rethink experiment and hypothesis

Any questions?