The Scientific Method
What is the third step of the scientific method?
What is a dependent variable?
The thing that changes as a result of the independent variable
What is data?
Information gathered through experimentation
Which comes first: observations or inferences?
Observations
Independent variable
The thing in the experiment that I change
What is the final step of the scientific method?
Communicate your results.
How many independent variables should I have in my experiment?
One.
Numerical data is an example of what kind of data?
Quantitative data.
What do I use to make observations?
My five senses: sight, smell, sound, touch, taste
What is an observation?
Things we notice with our five senses
Balls with different masses will still fall at the same rate of speed
Maya wants to know which laundry detergent is best at getting out spaghetti sauce stains. She smears spaghetti sauce on five white shirts. What is her independent variable? What is her dependent variable? What variables does Maya need to be controlled?
Independent - type of laundry detergent
Dependent - how clean the shirts are after being washed
Controlled - same washing machine; same shirt
Mary wants to know what her classmates' favorite movie is. She learns that 8 of her classmates prefer Harry Potter, 4 of her classmates like Lord of the Rings, 12 like The Avengers, and 1 likes the news. What kind of graph would be best to show her results? List two conclusions Mary can draw from her data.
A bar graph! Mary concludes that most people like The Avengers. She concludes that twice as many classmates prefer Harry Potter to Lord of the Rings.
Observation or Inference? I feel sick after eating my dog's food
Observation
What is an inference?
An inference is a guess about what is happening based on observations
What is the fourth step of the scientific method?
Analyze the results of the experiment
I want to know which wet food my cats enjoy best. Set up my experiment for me? What do I need to control for to be sure I'm getting accurate results?
Possible experiment - I can feed my cats and record how they react to their food (eating fast, purring)
I need to control how much they eat (so they aren't full from the day before), when they eat
Peter is interviewing his grandparents for a history project. They tell him what life was like for them in the 1950's. What kind of data did Peter collect?
Qualitative data
Observation or Inference? I got a good grade on my test because I studied
Inference
What is a trend?
A pattern observed in our data set
What if my hypothesis is wrong?
That's okay!
Seth wants to learn which of his friends is best at baseball. He pitches them ten balls and records who hits the ball most. What are Seth's variables?
What might be a problem in Seth's experiment that he cannot control for?
Independent - which friend is up to bat
Dependent - how many balls they hit
Controlled - the bat, the distance from the pitcher
Seth might not be able to control his own pitches (ex - he might pitch his friend Carl 7 good pitches and pitch his friend Danielle 4 good pitches)
What is the vertical axis called?
The y-axis
Marisa visits the circus with her parents and makes the following three statements.
1. Two kids are running away from two adults
2. The two adults are planning to take their kids home soon
3. There is a clown holding balloons
Which of these is not an observation?
2. The two adults are planning to take their kids home soon.
Marisa has inferred that this is why the kids are running from the adults.
What is an outlier?
A data point that does not fit our "trend"