Thinking Like a Scientist Using the Scientific Method

What do you observe? What inferences can you make from your observations?

Observations Any information collected with the senses. Quantitative – measureable or countable 3 meters long 4 marbles 50 kilograms 35 degrees Celsius Qualitative – describable, not measureable red flowers smells like fresh baked cookies Tastes bitter The skill of describing scientific events In experiments, record observations

Inference Conclusions or deductions based on observations. The process of drawing a conclusion from given evidence. Practice: Observations: I hear people screaming I smell cotton candy, popcorn, and hamburgers I see a lot of people Inference = ?

Look at these two sets of animal tracks. List 3 OBSERVATIONS Make an INFERENCE

Now what do you think? Make 3 OBSERVATIONS Make an INFERENCE

Now what do you think? Make 3 OBSERVATIONS Make an INFERENCE

Inference vs. Prediction Inference -what is happening or has happened Predicting -forecast of what will happen -based on past evidence - not always accurate -explanation of observations -not always true - an educated guess

SCIENTIFIC METHOD

SCIENTIFIC METHOD 1. Ask a Question -problem in an experiment -not personal taste -cannot be answered with a “Yes” or “No” Example: - Will a plant grow taller with fortified water than nonfortified waters?

SCIENTIFIC METHOD 2. Research -finding out more about your problem Examples

SCIENTIFIC METHOD 3. Form a Hypothesis - explanation to the problem - educated guess - If…..then….because statement Example: If I water a plant with fortified water, then it will grow nonfortified water because plants need nutrients to grow.

SCIENTIFIC METHOD - Independent -factor changed on purpose 4. Test hypothesis - Experiment - Variable - factor that changes - Independent -factor changed on purpose (Manipulated (input) -Dependent -factor changed in response to (Responding) independent variable (output) - Control -factors that don’t change -all experiments need one

Example: Variable- Dependent- Independent- Control-

SCIENTIFIC METHOD 5. Analyze Results -organize data into charts Example: Average height 7.5 cm 9.3 cm 6.1 cm 5 cm Plant food Week 1 Trial 1 2 3 Week 2 1 2 3 Week 3 Week 4 Week 5 Tap water Miracle grow water Rain water Bottled water

SCIENTIFIC METHOD Analyze Results -Graph results Example: Height in cm Type of Water

SCIENTIFIC METHOD 6. Conclusion MUST HAVES: –State the conclusion based on your data, restate your hypothesis, AND state whether your hypothesis was supported. – Comment on your method and the accuracy/precision of your data – Suggest improvements to the experiment 7. Communicate -share ideas with others Results -Scientific paper, presentation post on internet, etc… ***NEVER EXPERIMENT ONLY ONCE!!!*** Do 3 trials

Conclusion example My hypothesis was that the plant would grow taller with fortified water than nonfortified water, which is what happened. So, my data supports my hypothesis. My method was pretty reliable, although I’m not sure I was able to really control all variables. If I had it to do again, I would work even harder on keeping all variables the same. For example, I would make sure the temperature of the water was exactly for each water type. That would make my data more reliable.

Model Scientific Theory Scientific Law Fact -representation of an object or system physical (airplanes, dolls) mathematical (made of math equations/data) conceptual (big bang theory) Scientific -ties together many Theory hypotheses and observations Scientific Law -summary of many experimental results and observations -tells what happens, not why it happens Fact -complete truth -cannot be argued

-anything that helps you do a task Tools and Measurement Tool -anything that helps you do a task International -SI units System of -metric system Units -based on multiples of 10 Length -basic unit - meter (m) Mass -amount of matter an object contains -basic unit - grams (g)

-amount of space an object takes up -basic unit- liter (L) (liquids) Volume -amount of space an object takes up -basic unit- liter (L) (liquids) -cm³ (solids) Density -mass is in a given volume D = m V -g/ml- liquids -g/cm³ -solids Temperature -heat or energy -basic unit- kelvin (K) Time -basic unit-second (s)