Scientific Methods Section 1.3

Observations Using the senses to gather information Using the senses to gather information Scientific methods begin with observations Scientific methods begin with observations Good observations lead to testable predictions Good observations lead to testable predictions

Form a Question After making an observation, a problem or question is stated After making an observation, a problem or question is stated The question is based on information that you want to reveal about your observations The question is based on information that you want to reveal about your observations

Hypothesis Develop a testable prediction Develop a testable prediction A hypothesis is tested by conducting experiments A hypothesis is tested by conducting experiments The hypothesis may be supported by evidence but is never PROVED The hypothesis may be supported by evidence but is never PROVED

Gather Data Includes all information that scientists gather Includes all information that scientists gather Quantitative data= Measured in numbers Quantitative data= Measured in numbers (measurements, temperature, weight) (measurements, temperature, weight) o Qualitative data= descriptive

Conduct Experiment A variable is tested and compared to a control group A variable is tested and compared to a control group Experimental group= the group subjected to a specific factor Experimental group= the group subjected to a specific factor Control group= identical to experimental group except for the factor Control group= identical to experimental group except for the factor (used for comparison) (used for comparison)

Variables Independent variable= the factor being tested (example: fertilizer) Independent variable= the factor being tested (example: fertilizer) Dependent variable= the factor that is being measured (example: plant growth) Dependent variable= the factor that is being measured (example: plant growth) The dependent variable results from the independent variable The dependent variable results from the independent variable

Organize and Analyze Data Data should be placed in tables, charts, and graphs Data should be placed in tables, charts, and graphs Statistical analysis determines whether or not the data supports the hypothesis Statistical analysis determines whether or not the data supports the hypothesis

Form Conclusion Based on the conducted experiment, the results are summarized into a conclusion Based on the conducted experiment, the results are summarized into a conclusion Provides an explanation supported by data Provides an explanation supported by data

Publish Research Valid experiments can be published in scientific journals Valid experiments can be published in scientific journals If proper protocol has been followed, even student research can be published If proper protocol has been followed, even student research can be published

Inferences Conclusions made on the basis of facts or premises rather than on direct observations Conclusions made on the basis of facts or premises rather than on direct observations Example: where there is smoke, there must be fire Example: where there is smoke, there must be fire

Theories and Laws Theory= an explanation based on many observations supported by experimental results (example: theory of evolution) Theory= an explanation based on many observations supported by experimental results (example: theory of evolution) Law= a rule of nature that sums up related observations and experimental results Law= a rule of nature that sums up related observations and experimental results (example: law of gravity) (example: law of gravity)

Implementing Scientific Methods Problem solving skills are used to solve a wide variety of global problems such as human infectious diseases Problem solving skills are used to solve a wide variety of global problems such as human infectious diseases Communication allows scientists to build on the work of others Communication allows scientists to build on the work of others