2 Controlled Scientific Investigation: Determines the effect of an independent variable in an experiment.
3 1. Identify a Testable Question Can be investigatedTest only one variableWhich of these is a testable question?What makes a better pet, a fish or a dog?Which ice cream is better, chocolate or strawberry?Will Miracle Grow fertilizer make plants grow taller?
4 2. Research Collect information about the topic. Interview Inference: explanation of an observation based on prior experiences or supported by observations made in the experimentInterviewPrevious scientific investigationInternetBooks
5 3. State the HypothesisHypothesis: predicted answer to a question. What may be the possible outcome to the investigationCan be stated-Positively, negatively, or cause and effect (if…then)Example:The plants are taller with Miracle Grow. (positive)The plants are shorter with Miracle Grow. (negative)If Miracle Grow is used, then the plants will grow taller. (if, then)
6 4. Design an Experiment Test the hypothesis Plan for independent and dependent variables with repeated trials.Independent (manipulated) variable: variable being tested. You will only have 1 in an experiment.Dependent (responding) variable: variable that is measured.Controlled variable- kept constant and does not affect the outcome of the experimentList materials needed to conduct the experimentList the procedures to be followedPlan for recording, organizing, and analyzing data
7 Identifying Variables 4. Design an ExperimentIdentifying VariablesExample:Will Miracle Grow fertilizer make plants grow taller?Independent (manipulated) variable- fertilizerDependent (responding) variable- height of plantControlled variables- water, sunlight, same type of container and soil
8 5. Analyze Data Describe the relationship between the variables. tablesgraphsChartsWhen graphing remember:DRY: Dependent Responding variable –Y axisMIX: Manipulated Independent variable- X axis
9 5. Analyze DataObservations: gained by identifying and describing properties using the 5 senses or scientific tools and can be classified as…Qualitative Observations: an observation that contains descriptionsExample: The plants have shiny green leaves.Quantitative Observations: contain measurementsExample: The plant is 28 centimeters tall.
10 6. ConclusionOnce the results of an investigation are collected and recorded in appropriate graphs, tables or charts, the data should be analyzed to figure out what the data means. The results of the investigation are then ….Compared to the hypothesis and a conclusion should include…1. The relationship between the independent variable and dependent variables based on recorded data and 2. whether the hypothesis was supported or not.The conclusion is communicated to allow others to evaluate and understand the investigation.