Nature of Science

What is Science? investigate and understand the natural world (and only the natural world) explain events in the natural world Uses those explanations to make useful predictions. Scientists: 3. Scientists propose ___________ that can be ______ by examining evidence. *collect and organize information in a careful, orderly way *looking for patterns and connections between events. explanations tested Science is an organized way of using evidence to learn about the natural world.

How is Science Done? Science begins with an _____________. observation Various Examples- 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 an observation and write a proposed answer for the observation or question in an if/then format If I complete all of my assignment in Mrs. Thennis’ class, then I will pass the class. 

Conducting Experiments Want reliable and accurate results Controlled experiment: changes only one variable at a time (when possible) Other variables are controlled. Examples: When can not all variables be controlled?

Experimental Group and Control Group An experiment is based on the comparison between a Experimental Group with an Control Group. a) identical except for one factor. b) The control group serves as the comparison c) The experimental group has the changed variable.

WHAT IS YOUR EXPERIMENTAL DESIGN? Experimental Group How do you know? Control Group

Two variable in an experiment The independent variable is the variable that is deliberately changed by the scientist. - Manipulated The dependent variable is the one observed during the experiment. The result being measured - Responding

WHAT ARE YOUR INDEPENDENT AND DEPENDENT VARIABLES? How do you know? DEPENDENT:

Step 4: Recording and Analyzing Results 1. The data that has been collected must be organized and analyzed. Data Table – organize data Graphs – show trends and Comparisons Determine statistical significance

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.

Causal versus Correlational Causal: One variable causes the other to change. Correlational: One variable is related to another. May or may not be statistically significantly linked. Examples: Smoking causes lung cancer Smoking causes alcohol consumption?

What might influence this research

Step 5: 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. *results should always be the same before a valid conclusion can be reached.