Nature of Science

What is Science? Investigate the Natural World Propose explanations – from observations and experiments

Step 1: Science begins with an observation How is Science Done? Step 1: Science begins with an observation

Observation Activity Write down observations (description) about something in the room in your notebook. No using function – only description to see if the class can determine what you described.

Hypothesis A problem or a question is identified from observations. Step 2: Observation / Asking a Question Step 3: Form a Hypothesis Hypothesis A problem or a question is identified from observations. A possible explanation to the question or problem. Based on observation *stated in a way that is testable. A statement is considered “testable” if evidence can be collected that either does or does not support it. If/Then Why can some cells regenerate while other cells cannot What effect does temperature have on heart rate? Must be testable

YOUR HYPOTHESIS Think about any observation and write a proposed answer for the observation or question in an if/then format Example: If I complete all of my assignment in Mrs. Thennis’ class, then I will pass the class. 

Step 4 Design and Conducting Experiments Well Designed Provides: reliable and accurate results Is controlled - changes only one variable at a time Other variables are controlled. In your hypothesis what would need to be controlled.

Step 4: Design Includes an Experimental Group and Control Group comparison between a Experimental Group with a Control Group. Mrs. Thennis’ Experiment Experimental Group: Students Doing Assignments Control (opposite): Students not Doing Assignments

Do Your Experimental Group and Control Group Experimental Group (Group being experimented on) Control Group Exact opposite)

Continue Ex Design (Step 4) Two variable in an experiment The independent variable is the variable that is deliberately changed by the scientist. - Manipulated The dependent variable -one observed during the experiment. What is being measured? - Responding

WHAT ARE YOUR INDEPENDENT AND DEPENDENT VARIABLES? INDEPENDENT: (being changed) What is the difference between the Experimental Group and the Control Group?) One or two words DEPENDENT: (what is being measured at the end of the experiment?)

Step 5: Perform the Experiment

Longer Term Studies

Step 6: Recording Graphs – show trends and Comparisons Organized into a data table Title: The amount of iron in different cereal brands Graphs – show trends and Comparisons

There are two types of data: Quantitative data are: numbers and are obtained by counting or measuring. Qualitative data are: descriptions and involve characteristics that cannot be counted.

Step 7: Analyze the Experiment Compare data Look for trends Propose Explanations Analyze Sources of Error

Step 8: Drawing Conclusions The evidence from the experiment is used to determine if the hypothesis is Accepted or Rejected . Experiments must be repeated over and over. (Why procedures are important) *results should always be the same before a valid conclusion can be reached.