September 5, 2012 Aim: to discuss procedures for advisory Today’s greeting will be led by Ms. Douglas Daily News: have out your agenda and a pencil and form a circle at the front of the room Do Now: Make one word from all these jumbled letters: o r e n o d w Greeting Activity: What is advisory and how does it work? Paycheck review
September 5, 2012 Aim: to distinguish independent and dependent variables and write hypotheses Homework: Hypothesis 101 Do Now: Partner Check your homework Notes: Hypothesizing 101
Hypothesizing So much more than an educated guess
What does hypothesis mean? A proposition set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation-dictionary.com Huh?
What is a hypothesis? • A tentative statement that proposes a possible explanation to some phenomenon or event • An assumption you make about what you think will happen in your experiment and an explanation or reason for that belief • A useful hypothesis is a testable statement which may include a prediction based on some previous observation
Hypothesizing When you predict a possible answer to a problem or question that is based on one or more of the following: • Repeated observation • Research topic • Personal experience Then use your prior knowledge, observations, and experiences to explain your prediction.
Writing Hypotheses Aim: to identify when and how to write hypotheses.
When are hypotheses used? • Key word is testable • You must be performing a test of how two variables might be related VARIABLES • Independent Variables (IV) what you are changing • Dependent Variables (DV) what you are measuring • Constant Variables- what you are keeping the same
How do you write a hypothesis? Formalized Hypotheses examples: • If exposed to high levels of ultraviolet light, thenthe risk of skin cancer will increase because a high exposure to uv light effects the DNA in cells. • If leaf color change is related to temperature, then exposing plants to low temperatures will result in changes in leaf color. Notice that these statements contain the words, if and then. They are necessary in a formalized hypothesis. But not all if-then statements are hypotheses. For example, "If I play the lottery, then I will get rich." This is a simple prediction. In a formalized hypothesis, a tentative relationship is stated. For example, if the frequency of winning is related to frequency of buying lottery tickets. "Then" is followed by a prediction of what will happen if you increase or decrease the frequency of buying lottery tickets. If you always ask yourself that if one thing is related to another, then you should be able to test it.
Formalized hypotheses contain two variables. One is "independent" and the other is "dependent." The independent variable is the one you, the scientist, change and the dependent variable is the one that you observe and/or measure the results. In the statements above the dependent variable is blue and the independent variable is red. • The ultimate value of a formalized hypothesis is it forces us to think about what results we should look for in an experiment.
Hypothesis Do’s and Don’ts: Do 1. Generate several questions first and then choose the best one. That will be your guiding question. 2. Answer the guiding question with your best educated prediction. Try to make your guiding question simple and concise; be specific, such as, “Can Goldfish learn to swim in an obstacle course?” 3. Start your hypothesis by stating it in the following manner: "It is hypothesized that ..” or “If…then…” 4. Think of the hypothesis in terms of a cause - effect relationship and use the formula, “Because__therefore__since_”For example: (Because) Mary eats healthy foods and sleeps for 8 hours a night, (therefore) she will live a long life, (since) those who eat well and get enough rest live longer than others. 5. Or, use the method used in Science: “If__then__because___” IfMary eats healthy foods and sleeps 8 hours a night, then she will live a long life; because those that eat well and get enough rest live longer than others. Don’t • Don’t get stuck on just one question - brainstorm several. • Don’t make your guiding question too broad by avoiding words like all, never, and sometimes, such as in, “Can all fish think?” since you can not test all fish out there. • Delete the phrase “I believe” on the final draft as the hypothesis becomes a theory at the end. • Watch out for fragmented sentences – rephrase your statements if necessary to make it a complete sentence. • Remember that your hypothesis needs to be written so you can collect data.