Scientific Method & Data Collection

Thinking Like a Scientist§ Science is characterized by an

organized approach to learn how the natural world works

§ Scientific method: a logical approach to solving problems

Steps of the scientific method:§ Questions§ Hypothesis§ Experiment§ Observations & Data Collection§ Conclusion

Forming a Hypothesis§ Hypothesis: a proposed explanation for the way a particular aspect of the

natural world functions; an educated guess§ A good hypothesis must…

§ Simple & clear§ Predicts an outcome§ Must be testable

Designing a Controlled Experiment§ Variable: factor in the experiment that is being tested§ A controlled experiment = only one variable is changed

at a time§ Comparison between a control group with an

experimental group§ Identical except for one factor§ The experimental group shows the effect of the

variable that is being tested§ The control group remains constant/unchanged;

serves as the comparison

Variables in an experiment§ Independent variable: the factor in an experiment that

is changed§ Always on the x-axis of a graph

§ Dependent variable: the factor in an experiment that is measured or observed§ Always on the y-axis of a graph

Observing & Collecting Data

§ Observations = the use of the senses to obtain information§ 2 types of observations:

§ Quantitative = numbers are obtained by counting or measuring

§ Qualitative = descriptive; involve characteristics that cannot be counted

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Good vs. Bad ConclusionsGood conclusions…

ü Answer the question(s)ü Restate the hypothesis (were

you correct or not?)ü Mention any possible areas of

error

§ Bad conclusion examples:§ This activity was interesting and fun.§ We worked well as a team to solve the problem.§ This lab was hard and I didn’t get it.§ IDK

Drawing Conclusions§ The evidence from the experiment is used to

determine if the hypothesis is proven or disproven