Observations & Inferences in Science

Why do we DO science?What did we DO before we had science?At first, the answers involved tales of magic or legends.

Today, humans explore the natural world using a scientificapproach.

The early myths and legends answered the questions that primitive thinkers hadWhat are the lights in the night sky?Where did plants and animals come from?How did I come to be?The practice of asking and answering questions led to better questions and better answers.These questions and answers are based onThe collection of information is based onObservation & InferenceWhat does that mean?The goal of science is to: Investigate and understand nature;Explain events in nature;Use those explanations to make predictions.

Features of science:Science deals with the the natural world.Scientists collect and organize information in a careful, orderly way, looking for patterns and connections between events.Scientists propose explanations that can be tested by examining evidence.

Evidence Based on ObservationScience starts with observation.Observation involves using one or more of the senses:Sight, hearing, touch, smell, and tasteThe information gathered from observations is called evidence or data.

Two Types of ObservationsQuantitative

Qualitative What do you observe?

Describe at least four observations from the photo.

Are your observations quantitative or qualitative?

Quantitative ObservationsInvolve numbersCounting objectsMeasuring LengthMassVolumeTemperature

Qualitative ObservationsInvolve characteristics that describe the objects qualitiesColorTextureShapeSmell

As scientists make observations, they try to be objective and avoid bias.Bias is a preference for a particular point of view and may interfere with the outcome of the investigation.

Interpreting the EvidenceThe goal in science is to understand an observed event or activity.Scientists use observations to create an inference.

An inference is a logical interpretation based on prior knowledge and experience (observation).An inference is not backed by concrete evidence.If water samples are collected from different parts of a reservoir and they are all clean enough to drink, scientists may infer that all the water in the reservoir is safe to drink.

In Summary:Observations are any information collected with the senses. Quantitative can be measured or counted3 meters long4 marbles50 kilograms35 degrees CelsiusQualitative can be described with wordsred flowerssmells like fresh baked cookiestastes bitter

Inferences are conclusions or deductions based on observations.Practice: These are your observations:You hear people screamingYou smell cotton candy, popcorn, and hamburgersYou see a lot of peopleWhat can you infer?

You are at the Fair!

Look at these two sets of aLook at these two sets of animal tracks. tracks.List 3 OBSERVATIONSMake an INFERENCEMake an INFERENCE

Now what do you think?Make 3 OBSERVATIONSMake an INFERENCE

Now what do you think?Make 3 OBSERVATIONSMake an INFERENCEAny Questions?