Scientific Method. What is the goal of Science? Investigate and understand the natural world Explain...

Scientific Method

• What is the goal of Science?

• Investigate and understand the natural world

• Explain events in the natural world

• Use explanations to make useful predictions

Science as a Way of Knowing• How should you

think about science?• Science is an ongoing process– Involves asking

questions– Observing– Making inferences– Testing hypotheses

• What are the basic components of scientific inquiry?

• 1. Identify the Problem• 2. Formulate testable

Hypothesis• 3. Design & Conduct

experiment• 4. Analyze Data• 5. Develop Conclusion

Let’s Break it Down…..

• 1. Identify the Problem– Make observations using five senses

• Quantitative– Expressed as numbers, counting, or measuring

• Qualitative– Descriptive and involve characteristics that cannot be counted

– Collect information– Develop a question you can test

*A scientist observed maggots “appearing” on raw meat– He wondered how did this happen?*Question for experiment* • What is the cause or source of the maggots on the meat?

Breaking it down …….

• 2. Formulate a testable hypothesis– Could be an If/Then statement– Must relate to independent and dependent

variable

* hypothesis* If I see flies crawling all over the meat, then

flies produce maggots.-OR-Flies produce maggots

• How do we know what the IV and DV are?

variables- 2 kinds

• Independent variable- the factor the experimenter adjusts ( what “I” change)– AKA Manipulated Variable

• Dependant variable- the result (data your collecting)– AKA Responding Variable

Breaking down….• 3. Design and Conduct the experiment

– List materials needed– Make sure it is a valid procedure

• Experiment is not biased (one sided)

– Indentify Variables : IV, DV, constants, control• IV- what “I” change• DV- ‘D’ata you collect• Constants- what needs to stay the same to make the

experiment valid• Control- ‘the original’ unchanged test subject that the IV is

compared to

– Record observations– Collect Data– Multiple trials

Experiment example

• Materials: two jars, meat, gauze, flies, ect…• Control – uncovered meat• Constants - jars, meat, location, temperature,

time• IV- Gauze covering that keeps flies away from

meat• DV - Whether maggots appear or not• Record observations and collect data

– Quantitative & Qualitative• Multiple trials

Breaking it down…

• 4. Analyze Data– Organize data into charts, graphs and tables– Identify if the data supports the hypothesis

*In a lab report you put what you see in your graphs, charts and tables into complete sentences!!!!!!!!

* This shows your understanding of the data gathered

Data tables and Graphing

• CREATING A GRAPH – depends on your variables!– Bar Graph, Line Graph (single or multi –line) or Pie Graphs

• X-axis is the IV (unless multi-line) and Y-axis is the DV• Multi-line graphs have a Key ( which is IV) and time

always goes on x-axis!

Last break down….• 5. Develop Conclusion

– Make clear, concise statement based on results; written as a restatement of the hypothesis

– Accept/reject the hypothesis and explain why– Communicate results– Identify sources of error– Determine the need for further research

*Maggots form only when flies come in contact with meat, so his hypothesis “flies produce maggots” was correct. Spontaneous generation of maggots did not occur.