Observation vs. Observation vs. InferenceInference

““You can observe a lot just by You can observe a lot just by watching.” - Yogi Berrawatching.” - Yogi Berra

What is an observation?What is an observation?

When you observe, you become aware When you observe, you become aware of something using your senses.of something using your senses.

Your five senses are smell, taste, sight, Your five senses are smell, taste, sight, touch, and hearing. touch, and hearing.

In an observation you simply describe In an observation you simply describe something you observe. something you observe.

An An observationobservation is a statement of fact is a statement of fact gathered by using your five senses.gathered by using your five senses.

Two Types of ObservationTwo Types of Observation

QUALITATIVEQUALITATIVE QualitativeQualitative observations observations describedescribe what what

we observe using adjectives.we observe using adjectives. ““QualitQualitative” = quality (descriptive)ative” = quality (descriptive)

Example: The flower has white petals.Example: The flower has white petals. Example: The music is loud.Example: The music is loud.

TwoTwo Types of Observations Types of Observations

QUANTITATIVEQUANTITATIVE QuantitativeQuantitative observations observations measure measure what what

we observe using numbers.we observe using numbers. ““QuantitQuantitative” = quantity (numerical)ative” = quantity (numerical)

Example: The flower has seven petals.Example: The flower has seven petals. Example: The volume was on 10 (max.).Example: The volume was on 10 (max.).

Which is better?Which is better?

Qualitative descriptions tend to be more Qualitative descriptions tend to be more subjectivesubjective (dependant on the observer), while (dependant on the observer), while quantitative are more quantitative are more objectiveobjective (independent of (independent of the observer). the observer).

Scientists make Scientists make quantitative observationsquantitative observations, , which can be compared which can be compared preciselyprecisely and and objectivelyobjectively . .

Qualitative: The road is long. (describes)Qualitative: The road is long. (describes) Quantitative: The road is 7 km long. (measures)Quantitative: The road is 7 km long. (measures)

Extending our ObservationsExtending our Observations

Sometimes scientists must make very Sometimes scientists must make very careful observations. There are some careful observations. There are some things that cannot be observed using just things that cannot be observed using just your senses. (Examples: radiation, sound your senses. (Examples: radiation, sound waves, planets, cells, etc.)waves, planets, cells, etc.)

Scientists use tools such as Scientists use tools such as microscopes, telescopes, satellites to microscopes, telescopes, satellites to extend their senses.extend their senses.

What is an inference?What is an inference?

An An inferenceinference is an is an explanationexplanation for an observation for an observation you have made. you have made.

They require They require thoughtthought and are based on your past and are based on your past experiences and prior knowledge. experiences and prior knowledge.

They are often changed when new observations They are often changed when new observations are made.are made.

Again, observations are information we gather Again, observations are information we gather directly through our senses……Inferences help directly through our senses……Inferences help explain those observations.explain those observations.

Here are some examples!Here are some examples!

Observation: The grass on the school’s front Observation: The grass on the school’s front lawn is wet.lawn is wet.

Possible inferences:Possible inferences: It rained.It rained. The sprinkler was on.The sprinkler was on. There is dew on the grass from the morning.There is dew on the grass from the morning. A dog urinated on the grass!A dog urinated on the grass!

All of these inferences could explain why the grass All of these inferences could explain why the grass is wet. They are all based on prior experiences. is wet. They are all based on prior experiences. We have all seen rain, sprinklers, morning dew, and We have all seen rain, sprinklers, morning dew, and dogs going to the bathroom.dogs going to the bathroom.

Here are some examples!Here are some examples!

Observation: the school’s fire alarm is Observation: the school’s fire alarm is going off.going off.

Possible inferences:Possible inferences:The school is on fire.The school is on fire.We are having a fire drill.We are having a fire drill.A student pulled the fire alarm.A student pulled the fire alarm.

Again, these are all logical explanations for why Again, these are all logical explanations for why the fire alarm is going off.the fire alarm is going off.

ObservationObservationRecord 3 observations about your science Record 3 observations about your science

classroom.classroom.

1.1.

2.2.

3.3.

List 3 inferences based List 3 inferences based on your observations.on your observations.

1.1.

2.2.

3. 3.

Scientific ModelsScientific Models

A A scientific model scientific model is a representation of is a representation of an object or event that can be studied to an object or event that can be studied to understand the real object or event.understand the real object or event.

Examples include ball and stick models Examples include ball and stick models in chemistry, drawings of sound waves, in chemistry, drawings of sound waves, and computer models of car designs and and computer models of car designs and weather patterns.weather patterns.

Mystery TubesMystery Tubes Observe the teacher’s Mystery Tube. Observe the teacher’s Mystery Tube. Write down what you see and draw a Write down what you see and draw a

picture.picture. Write your prediction or inference of what Write your prediction or inference of what

is happening inside the tube.is happening inside the tube. With a partner try to make a model of the With a partner try to make a model of the

mystery tube.mystery tube. When done, check with real Mystery When done, check with real Mystery

Tube to see if you were right!Tube to see if you were right!