Cause and Effect Notes “If you give a mouse a cookie…” Joffe Numeroff
What is cause and effect? You can think of cause and effect as an IF…THEN…statement Examples: –If you give a mouse a cookie then he is going to want a glass of milk. –If a plant is not watered then it will die –If Mrs. Webber does not get her coffee in the morning then she will be very grouchy by fifth period.
Can you think of an If…Then…statement? In your notes write your own IF…THEN…statement
What does cause and effect have to do with Science? The purpose of an experiment is to ask a question about what is causing something to happen. You can think of an experiment as a test to see if something you have control over or can change (independent variable) causes the effect of something else to happen (dependent variable).
Controlled Experiment A controlled experiment is important because if you change more than one variable at a time you will not know which variable is causing your effect
Control Variables In an experiment you want to keep everything the same except for one variable Control Variables: a variable that is kept the same
Independent Variables Independent Variable: variable that is changed by the scientist (think I AM THE SCIENTIST; THEREFORE I…INDEPENDENT CHANGE THE VARIABLE) This is the variable the scientist believes is causing the effect
Dependent Variable Dependent Variable: variable that changes in response to the change made by the scientist This is the effect The thing that is being measured or observed
Tricky Vocabulary There are other names that are used for independent and dependent variables –Independent = manipulated –Dependent = responding
First step of the scientific method Ask a questions about something we want to know. Example: If Mrs. Webber does not get her coffee in the morning will she really be grouchy by fifth period?
Second step of scientific method Form a hypothesis: an education guess A hypothesis can be written in an IF…THEN…statement You are guessing what effect the thing you change (independent variable) has on something else (dependent variable)
PRACTICE Question: Does fertilizer effect the growth of a plant? What are the variables? What are the control variables? What is the independent variable? What is the dependent variable?
Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.