Chapter One – Part 2 Scientific Method

When scientists are thinking and inquiring information to investigate and explain a situation what method are they using? When scientists are thinking and inquiring information to investigate and explain a situation what method are they using? Scientific Method Scientific Method

What steps does a scientist use in the scientific method? What steps does a scientist use in the scientific method? Identify the problem – recognize and research Identify the problem – recognize and research Form a hypothesis – a statement that can be tested Form a hypothesis – a statement that can be tested

Begin an experiment – they test the hypothesis by making predictions and gathering new data: Begin an experiment – they test the hypothesis by making predictions and gathering new data: variable variable control control data data

Scientists then come up with a conclusion Scientists then come up with a conclusion Note: this can lead to another hypothesis Note: this can lead to another hypothesis Develop a theory

USING SCIENTIFIC METHOD A biology class raised guppies for a class project. Paula thought the guppies would have more young if the light in the aquarium was turned off part of the time. Other students thought the light should be left on all the time. But, Paula had observed that her guppies at home had more young than the ones at school. She also knew that she kept her aquarium light turned off part of the time. The class had a problem. What was the problem? A biology class raised guppies for a class project. Paula thought the guppies would have more young if the light in the aquarium was turned off part of the time. Other students thought the light should be left on all the time. But, Paula had observed that her guppies at home had more young than the ones at school. She also knew that she kept her aquarium light turned off part of the time. The class had a problem. What was the problem?

The Problem: What should they do about the aquarium light? The Problem: What should they do about the aquarium light? Paula needed to do some research at the library. She found out what temperature to keep the water and the amount of water needed. However, there was little information about how much light a guppy needs. So what did she develop at this point? Paula needed to do some research at the library. She found out what temperature to keep the water and the amount of water needed. However, there was little information about how much light a guppy needs. So what did she develop at this point? Answer: Hypothesis Answer: Hypothesis Paula’s: “If the light is turned off part of the time, then the guppies will have more young.”

What is Paula’s next step? What is Paula’s next step? Answer: test her hypothesis Paula divided 16 guppies into two equal groups. She put the groups into separate tanks and labeled them group A and group B. She kept the temperature in the tanks the same. She put the same amount of water in each tank. The light for group B was left on 24 hours a day. The light for group A was turned on for 12 hours and off for 12 hours each day. So, what is next?

Answer: Collecting Data Answer: Collecting Data Paula recorded the number of adult guppies she put into the tank. Once a week for four weeks, she recorded the number of young produced by each group. She removed the new young each week so she could count more easily. Paula recorded the number of adult guppies she put into the tank. Once a week for four weeks, she recorded the number of young produced by each group. She removed the new young each week so she could count more easily. What was Paula’s last step? What was Paula’s last step?

Paula’s last step was to conclude whether or not the problem was solved. Paula’s last step was to conclude whether or not the problem was solved. At the end of the experiment group A had more young than the guppies in group B. At the end of the experiment group A had more young than the guppies in group B. So, What was the conclusion? So, What was the conclusion? Answer: Paula concluded that 12 hours of light and 12 hours of dark caused the difference. She had determined that the guppies had more young when they were only exposed to 12 hours of light and 12 hours of darkness.