Scientific Process Skills Unit 1: Building a Community of Scientists and Engineers

What are Scientific Questions?  Questions about the natural world  The answers to scientific questions are found by observing, measuring or investigating  Not based on opinion or personal values  Can be tested and results can be validated.

Good Vs. Bad Questions-What’s the difference? Good Questions  Does Pepsi have more carbonation than Coke?  What is the effect of cigarette smoke on the lungs?  What is the effect of adding fertilizer to grass have on the greenness of the grass? Bad Questions  Did Abraham Lincoln think blue was a terrible color?  Is this horse pretty?  Which flower smells the best?

Good Science Question, or not?  If salt is added to water, would the solution still boil at the same temperature?  Which is better, Coke or Pepsi?  What types of fertilizer will improve plant growth, but not harm the environment?

What is a Hypothesis  A possible explanation for a set of observations or answer to a scientific question  Hypotheses must be testable You should be able to find out if a hypothesis is supported or unsupported by performing an investigation or making observations.  Writing your hypothesis in the form of an “If…then…” statement ensures the hypothesis is testable

Examples of a hypothesis  If the pipe has a larger diameter, then the amount of water flowing will increase.  If I add fertilizer to my garden, then my plants will grow faster.  If I brush my teeth every day, then I will not develop cavities.

Making a hypothesis from a science question Question: What happens when a piece of solid ice is heated? Hypothesis: IF solid ice is heated, THEN the ice will melt and form liquid water.

Planning a Procedure  Plan must have a list of all materials needed  Procedures are best understood by giving a step-by-step detailed plan to follow  Must allow for someone to take your experiment and repeat it obtaining the same results.

Imagine a procedure as a recipe  Could someone take this procedure (recipe) and find (make) the EXACT same thing you did?

Variables  The factors in an experiment that can be change  In a scientific experiment, only ONE variable is changed at a time.  The 3 types of variables in an experiment…

1. Independent Variable ( Manipulated Variable)  The variable that is purposely changed

2. Dependent Variable (Responding Variable)  The factor that might change as a result of changes in the manipulated variable

3. Controlled Variable(s)  All of the other factors must be controlled  This means keeping all of the conditions the same except the independent/manipulated variable

Example: If testing how the amount of sunlight affects the height of a plant…  What is the manipulated variable?  What is the responding variable?  What other variables need to be controlled in this investigation?

Example: If testing how the amount of sunlight affects the height of a plant…  What is the manipulated variable? The amount of sunlight  What is the responding variable? The height of the plant  What other variables need to be controlled in this investigation? The amount of water, type soil, size of container

What is an Operational Definition?  A statement that describes how a particular variable is to be measured, or how an object or condition is to be recognized  The word operational means “describing what to do.”  Operational definitions are used whenever a term does not have a single, clear meaning

Examples:  What is the operational definition for measuring temperature? …in degrees using Celsius or Fahrenheit scale  What is operational definition for plants were grown in a sunny area? …A sunny area is an area that receives an average of 10 or more hours of sunlight each day.

Data …collected during an investigation needs to be carefully recorded and then organized so it can be easily interpreted. *Ways to organize data include -  A data table is an organized arrangement of information in labeled rows and columns.  A line graph is used to display data that show how one variable (the responding variable) changes in response to another variable (the manipulated variable).  A bar graph is a diagram in which data about separate but related items are being compared  A circle graph shows data as parts of a whole.

Interpreting Data  Analyzing the data collected during an investigation to make specific claims.

Example 1 Interpreting Data- What information can you get from the data below?

Example 2 Interpreting Data- What information can you get from the data below?

Example 3 Interpreting Data- What information can you get from the data below?

Example 4 Interpreting Data- What information can you get from the data below?

Making a Conclusion  Drawing a conclusion means making a statement summing up what you have learned from an experiment  Conclusions either support or do not support hypothesis  Data obtained during the investigation is used to support the conclusion