Inductive Versus Deductive Reasoning

1. Inductive Versus Deductive Reasoning

2. Warm Up Write the statements that follow. Identify the following statements as inference or observation ___1. Today is a hot sunny day. ___2. The little boy is wearing a spacesuit. He is an astronaut. ___3. Ms. Berry is wearing pink. ___4. If you are running a fever, then you are probably sick. ___5. Carl came to class 5 minutes late. Carl’s hair was not brushed. Carl must have gotten up late.

3. Deductive Reasoning What is it? • The process of demonstrating that if certain statements are accepted as true, then other statements can be shown to follow from them. • It is a logically valid explanation. • Most often used by scientists • It begins with a general statement and concludes something specific. • Uses if and then statements AKA cause and effect statements • Ex. If the baby is crying then he is upset • Ex. If you don’t put on suntan lotion then you will get sunburned

4. Inductive Reasoning • What is it? • The process of reasoning that a general principle is true because the special cases you’ve seen are true. • It is NOT logically valid. • You begin with something specific and make a general statement. • It uses a series of observations to come to a conclusion. • Inferences are often used when reasoning this way. • Ex. My son finds it entertaining to flush the toilet (specific statement). All one year olds enjoy flushing the toilet (generalization). Ex. Carl came to class 5 minutes late. Carl’s hair was not brushed. Carl must have gotten up late.

5. Reasoning Data Inference Made based on observation Becomes Is used in… Is used in… Observation (5 senses,prior knowledge) Inductive reasoning Deductive reasoning Specific to general General to specific Hypothesis “educated guess” Not logically valid Logically valid Uses a series of observations To come to conclusion Uses if and then statements Scientists use most often