Scientific Method

Vocabulary to Know: Basics on Scientific Method Variable Control

Science Science and nature follow a set of rules which govern the way things work. –Gravity is an example. Science explanations can be changed over time. Why do you think this is possible?

It’s a lot of work- Why? We spend time teaching, using and reviewing the scientific method because: –It makes you think –It asks you to predict –It makes you practice being careful and organized –It helps to make the content relevant to your world beyond school –It combines your previous knowledge and experiences with new content

Keep in mind the big picture We will DO science (experiments and observations) We need to make sure this science is valid and repeatable We also need to make sure we can communicate what we did and what we learned These are the true reasons for the way we do the scientific method and their write-ups

Using the scientific method requires that one be a good observer. observationinference involves a judgment or assumption uses the five senses

Scientific Method The scientific method is an organized set of investigation procedures used by scientist when experimenting. The are six general steps for the scientific method. Don’t think of them necessarily as steps, though. You can always go back and repeat…

6 General Steps of the Scientific Method 1.State the Problem 2.Gather information 3.Form a hypothesis 4.Test the hypothesis 5.Analysis data 6.Draw conclusions

Stating a Problem Begin with a general observation in your surroundings. Ask a “why” question about something that you see. State the problem.

Researching and Gathering Information Do some research on your problem…do a background check. You need to have a basic understanding of the topic that you are investigating.

Form a hypothesis A hypothesis is a possible explanation for a problem using what you know and what you observe. This is what you think will happen when you do your experiments. You will test your hypothesis. Example: If soil temperatures rise, then plant growth will increase.

Test the hypothesis Test your hypothesis through experimentation. The most common way to test a hypothesis is through the use of an experiment—this tests the effect of one thing on another using controlled conditions.

Experiments When doing a experiment you will need to think of all of the factors that will effect the overall experiment Experiments contain at least 2 variables.

Variables of an Experiment –A variable is a quantity that can have more than a single value. Dependent variable: value changes according to the changes in other variables Independent variables: Variable YOU change to see how it will affect the dependent variable –If I have 2 plants, but I only water one for 3 months I think the watered plant will grow bigger because plants need water to grow.

Experiments Continued Another key factor to doing an experiment is having a control and a constant. –A control is the standard by which the test results can be compared. –A constant is a factor that does not change when other variables are changed.

Data Observations are also called data. There are two types of data. qualitative dataquantitative data descriptions; measurements; no numbersmust have numbers Include tables, graphs, and photographs.

Analysis of Data Always record what you observe and organize these observations. If a scientist doesn’t record what he did, than what proof does he have of what he did? Use graphs and tables to display your observations. Be ORGANIZED!

Draw Conclusions From the review of your data, decide whether or not your hypothesis was correct or incorrect. Repeat the experiment if correct or revise if necessary. Be careful of bias: what a person expects changes how the results are viewed

Non-Scientific Uses of the Scientific Method  Using a recipe to cook supper  Advertising: Trial and Error  Sports  Writing a news story  Finances  Etc.

Let ’ s put our knowledge of the Scientific Method to a realistic example that includes some of the terms you ’ ll be needing to use and understand.

Problem/Question John watches his grandmother bake bread. He ask his grandmother what makes the bread rise. She explains that yeast releases a gas as it feeds on sugar.

Problem/Question John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

Caution! Be careful how you use effect and affect. Effect is usually a noun and affect, a verb. “ The effect of sugar amounts on the rising of bread. ” “ How does sugar affect the rising of bread? ”

Observation/Research John researches the areas of baking and fermentation and tries to come up with a way to test his question. He keeps all of his information on this topic in a journal.

References How Scientists Work: What is the Scientific Method?. United Learning (2003). Retrieved January 3, 2006, from unitedstreaming: Methods of Science. Glencoe Science: Physical Science (2002). Powerpoint obtained from: he%20Scientific%20Method.ppt he%20Scientific%20Method.ppt on August 20, 2008