Tools of Environmental Science Chapter 2

The Scientific method Observation Hypothesis Prediction Experiment Organize and Analyze Conclude Repeat experiment Communicate results

What is the difference between a Hypothesis and a Prediction? Testable explanation for an observation. More than a guess. Should be logical. Should be based off of previous knowledge. A logical statement about what will happen if the hypothesis is correct.

Two characteristics of a good experiment: Tests a single variable. A control is used.

Variables: Independent: this is the variable adjusted by the experimenter. Dependent: this is the variable that adjusts in response to the independent variable. Example if we were to test miracle grow on plants we (the experimenter) would adjust the amount of miracle grow. In response to that, the plant would grow. Amount of miracle grow=independent variable (x-axis) Amount of growth= dependent variable (y-axis) Dependent variable Independent variable

Experimental Group: The group that receives the experimental treatment (the plants receiving miracle grow) Control: The group receiving no experimental treatment (the plants that get no miracle grow). Constants: All the things that are the same for all of the groups (quantity of water, sunlight, amount of soil, size of pot…)

Lesson 2.2 Statistics and Models

Statistics Collection and classification of data that are in the form of numbers. How do scientists use statistics? Summarize Characterize Analyze Compare data In statistical terms an average is called a mean Distribution is the total range of numbers (ie: from 60-85 inches) . A bell shaped curve represents a normal distribution Probability is the likelihood that an event will occur.

Sample size In statistics a sample is a group of individuals or events selected to represent the population. Sample size is very important for accuracy of results, reliability and validity.

Models Representations of objects and systems. Several types Physical Graphical Conceptual Mathematical

Physical model of a sonogram/fetus Physical Models Three dimensional models you can touch. Closely resemble the object or system they represent although they may be bigger or smaller. Physical model of a sonogram/fetus

Star charts, maps of forest coverage, depth of water, etc. Graphical Model Graphs and charts. Star charts, maps of forest coverage, depth of water, etc.

Conceptual models A verbal or graphical explanation for how a system works or is organized. Flow charts, verbal descriptions, drawings of how something works or is put together.

Mathematical model One or more equations that represent the way a system or process works.

Making informed decisions Lesson 2.3

Decision making model A systematic process for making a decision. Gather Information Consider Values Explore Consequences Make a decision