Observations, Data Tables, Graphing, &

Variables ReviewWednesday, August 5th, 2015

Classifying Observations

Identify whether the following observations are quantitative/qualitative and objective/subjective:

Quan. Qual. Obj. Subj.

Chemistry is the best class in the world.The chemistry class has 28 students.Everyone agrees Miss Scott is the best chemistry teacher.

VariablesThe changing factors in an experiment are called the variables, and they are the first thing you must worry about when designing your experiment.

- Independent variable: Factor that is changed by the scientist

- Dependent variable: Factor(s) that is measured in response to the independent variable

- Controlled variable(s) – also known as constants: Factor(s) that are kept the same between experimental groups

Practice ScenarioA florist wants to determine if the amount of humidity in the air affects the orchid plant. She takes two cuttings and plants them in the same type of pot in the same type of soil. She waters each plant three times a week, and they are exposed to the same amount of sunlight. She keeps one plant outside in the dry Arizona air (10% humidity) and she keeps one inside a greenhouse (humidity 70%). Every week she counts the number of flowers.

Rules for Reporting Data: Data Tables

•Detailed Title & Include the Data•Organized Data: Use a Ruler•1st column – Independent variable•2nd-millionth column – Dependent variable

Rules for Graphing

•Descriptive Title•Use a ruler! Should be big ~ ½ page!•X-axis (independent variable) with labels & units• Y-axis (dependent variable) with labels & units• Even increments/scale•Key/legend (if you have more than one set of data)