SQRS On page 4 of your science notebook answer the following question in complete sentences: What kind of factors influence whether or not you get your homework completed at night? Consider the activities you are involved in, your coming home from school routine, your family interactions, your motivations, etc.

Variables, Qualitative & Quantitative Data In scientific Experiments In a Glance: variables, independent variables, dependent variables, controlled variables, qualitative data & quantitative data

Genius Vocabulary Variable: any factor, trait, or condition that exists in differing amounts or types. Variables must be measurable. For example, weight and mass, color change, temperature change, etc. Love, however, is not a variable because it’s not measurable. You cannot measure how much in love someone is Independent Variable: the ONE variable that is changed by the scientist in an experiment. Dependent Variable: the things the scientist focuses his or her observations on to see how they respond to the change made to the independent variable. This DEPENDS on the change made by the scientist, or the INDEPENDENT VARIABLE Controlled Variables: quantities that the scientist wants to remain constant and unchanging Scientific Bias: The assumption that a theory is true or false without evidence or proof, or the attempt to dismiss or discourage research to confirm or deny a theory.

How many can you have in an experiment? How variables occur in Experiments: Variable Type How many can you have in an experiment? WHY? Independent Variables 1 The independent variable is the ONE thing changed by the scientist. You can only have one independent variable because if you changed more than one thing it would be hard to figure out which change caused the results/outcome of the experiment. Dependent Variables The amount of dependent variables varies, but there can be more than one. A scientist can be observing and measuring more than one thing in an experiment. Controlled Variables Most experiments have more than one variable, however it depends on the experiment. Scientist need controlled variables in an experiment so that they know that the results of experiment or the changes that occur are because of the independent variable rather than something else.

To determine the experiment variables Ask yourself: 1. What factors am I trying to test? Answer: Independent Variable 2. What factors will I use to measure the progress of my test? Answer: Dependent Variable 3. What factors do I need to keep constant? Answer: Controlled Variable

Example: A scientist decides to perform an experiment to see how the amount of liquid used to water a plant will effect the growth of the plant. Independent Variable Dependent Variable Controlled Variable The ONE thing you change. Limit to only ONE in an experiment. The change that happens because of the independent variable. Everything you want to remain constant and unchanging. Example: The Liquid used to water each plant. Example: The height or health of the plant. Example: Type of plant used, pot size, soil type, etc.

Review: Independent Variable Dependent Variable CONTROLled Variable What I CHANGE Dependent Variable What I OBSERVE CONTROLled Variable What I KEEP THE SAME

Create a t-chart like the one below on page 4 of your notebook. Data Qualitative Quantitative

Qualitative or Quantitative Data? Qualitative Data: Qualitative sounds like the word quality, and it refers to the data that can be recorded or described using your five senses. What does it smell like? How does it look? What does it feel like? Does it make a sound? What does it taste like? (sight, sound, taste, touch, and smell) THIS IS NOT MEASUREABLE OBSERVATION! Example: The tree is green. It smells like sap. It feels like sand paper. Quantitative Data: Quantitative sounds like quantity. quaNtitative data refers to information that can be recorded using Numbers. Quantitative has an “N” in it. Use this to remember that it measures numbers! THIS IS A MEASURABLE OBSERVATION! Example: She is 63 inches tall. She has four brothers. He made $27 at work. The distance from here to Nashville is 174 miles. It will take 2 ½ hours to drive there.

Your Turn/Exit activity! Choose one slip of paper from the bucket. Determine if your example is qualitative or quantitative. If you have QUALITATIVE DATA go stand by the WINDOW. If you have QUANTITATIVE DATA go stand by the STORAGE CABINETS and be prepared to read it aloud to the class. Make sure to listen while others read theirs so we can determine if everyone is standing on the correct side of the room!

What is bias? Prejudice in favor of or against on thing, person, or group compared with another. Bias is considered to be unfair. Example of a non-scientific based bias: Two people are interviewing for the same job. They have the same qualifications, experience, etc. The boss who is hiring the new employee happens to be the mother of one of the two people interviewing for the job. The boss has a bias towards her child because she is related to him/her and is therefore more likely to hire him/her instead of the other candidate. Example: If you have a ground-breaking idea, theory, or hypothesis that you think will change the world you may only collect data, research, and input that supports your idea rather than examining all possible data, research, and input. By ignoring information that may prove your idea to be wrong, you are manipulating the results and being bias because you want your idea to be proven correct.

Scientific experiments? How does bias effect Scientific experiments? Bias in science can be defined as our tendency to focus on evidence that confirms our prior expectations. Once our minds alight on a theory, our impulse is to reassure ourselves that it’s true, not set out to disprove it. Scientists who ignore data, evidence, or materials that disprove a theory or idea to be wrong are being biased, and therefore their theory is false. If one scientist discourages another scientist from re-performing an experiment to check the validity of the outcome, the first scientist is being bias because he/she is afraid that the second scientist will consider all the data and prove the original theory to be false.