Opener Imagine that all the birds around the school are dying. How might you investigate the problem? Write a brief description of your investigation. Which stages of scientific investigation are present within your answer?

1.2 Scientific Methods

Why is the geese population boom over? Steps of the scientific method 1.Making observations 2.Question 3.Research/Prior knowledge 4.Forming a hypothesis 5.Experiment 6.Data/Results 7.Conclusions 8.Report

Making Observations The act of noting or perceiving objects or events by using the senses Can be directly or indirectly observed Begins with an observation that leads to questions

Research/Prior Knowledge Research Look up background information to gain further information about your question May find the answer to your question Prior knowledge Relying on what you already know about that topic.

Forming a Hypothesis Possible explanation that can be tested by observation or experimentation. Attempt to make a connection between an observation and information Written as an If…then statement Not a guess!!

Scientific Experiments Procedure that is carried out under controlled condition to test a hypothesis. Controlled Tests 1 factor at a time and uses a control group Control group – serves as a standard of comparison because the group receives no experimental treatment

Dependent vs Independent Variables Variable – the 1 factor that is changed w/in the experimental group Independent variable The single factor that scientists change in an experiment Dependent variable Factors that may change in response to the independent variable Typically this is how you going to measure if there was a difference.

Study done w/out Experimentation Why? An experiment is not possible or not ethical Researchers attempt to find connections in data gathered. –Ex. Dental plaque contributes to heart disease

Analyzing Results Look at the results of the experiment and determine what they are saying. They be placed in a table, graph or chart to make the results easier to see My require you to change your hypothesis

Draw Conclusions and Report Results Explains whether or not their hypothesis was correct and why. Report Results This will allow other scientists to study what you did and repeat the experiment to verify their results.

Preventing Bias Scientists try to prevent bias from affecting their work but bias can still influence an experiment Sources of funding, personal involvement in an product and other conflicts of interest can affect an experiment

Scientific Theories In science when related hypotheses are well supported and explain a great amount of data, these hypotheses maybe put together to form a theory The main difference between a theory and a hypothesis is that a hypothesis is a specific testable predication for a limited set of conditions and a theory is a general explanation for a broad range of data

Example: Tomatoes Plant 20 seedlings = tomatoes harvested Plant 20 seedlings w/ fertilizer = >100 tomatoes harvested What can you conclude? What other factors may affect the growth? –weather better that year, different type of tomato seed, fewer pests than last year Hypothesis –If I use fertilizer then the tomato crop will increases in production

Experiment Field 1 –Brand A tomato seed –Water three times a day for 15 minutes –Similar type of soil – Try to control pests –Doesn’t receive fertilizer Field 2 –Brand A tomato seed –Water three times a day for 15 minutes –Similar type of soil –Try to control pests –Receives fertilizer

Control –the group that is being compared to, normal conditions –Unfertilized tomato plants Independent variable –the factor the differs among the test groups –fertilizer Dependent variable –the measurable change that results from changing the independent variable – # of tomatoes yielded Results –Unfertilized = 55 –Fertilized = 82 Conclusion –The fertilizer caused an increase in the tomato crop