Physical Science

What do you see?

What do you observe here?

What are Observations?

 Gathering of

information

by using our

five senses

 sight, smell, hearing, touch, taste

What do you observe here?

What do you observe here?

Observations are facts!

 These look to be foot prints of some kind  Some prints are wider/some are narrow  The first image, the sets of prints were separate  The second and third images, the sets of prints had separate regions and also a region where prints were together   Some prints were more /less spaced from others Prints all had 3 “point” sections to them  We could count the number of each kind of print in all the pictures  Prints are black on a white background

What if you said…?

 Two different animals were going to the same spot.

 The two animals got in a scuffle or played or one was chasing/hunting another  The animal with the smaller prints flew away / was carried by the other animal / was killed by the other animal  The two animals came at separate times and were smelling or searching the same area and we see their footprints.

Definition of Observation

• • • 

Observation:

when studying something describe only facts that you can see, touch, taste, smell and hear. you are not making any guesses.

NOT AN OPINION!!

Ohh… This liquid is

green

and it is leaking from a

brown

can. It smells like a sewer.

What else is important?

   What test must an observation pass to be considered a scientific fact  Must be repeatable (can be done over & over again & everyone agrees – “indisputable”) What are some factors that may lead to an incorrect observation?  Incompetent observer  Poor conditions Find the two types of observations 

qualitative

and

quantitative

Quantitative Observations:



Quantitative Observation:

Ohh…

5 liters

of liquid has leaked from a

2-kiloliter

can. It is leaking at a rate of

5 mL/sec

.

• • • • when studying something describe only facts that you can measure. you are not making any guesses. scientists use SI units!

THIS IS NOT AN OPINION!!

Qualitative Observation:



Qualitative Observation:

• • when studying something describe only facts that you can see, touch, taste, smell and hear. you are not making any guesses.

•

NOT AN OPINION!!

Ohh… This liquid is green and it is leaking from a brown can. I also smell it.

What is an Inference?

 an

explanation

have made for an observation you  What does an inference do?

 it tries to make sense of what you have observed  What are your inferences based upon?

 based on your past experiences and prior knowledge  may change when new observations are made

What are some inferences we can say here?

Definition of Inference

• • •  Inference: using your observations to make a

guess

about an object or an outcome based on prior knowledge or experience.

THIS CAN BE A SCIENTIFIC OPINION.

Based on my

observations

, I

think

that this can is

old

and is leaking a

toxic

substance.

EXAMPLE #1

  

Observation

: 

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

Possible inferences

: 

It rained.

  

The sprinkler was on.

There is dew on the grass from the morning.

A dog urinated on the grass!

All of these inferences could possibly explain why the grass is wet but we can’t say for sure which is correct without actually viewing the grass becoming wet. They are all based on prior experiences. We have all seen rain, sprinklers, morning dew, and dogs going to the bathroom.

EXAMPLE #2



Observation

: 

The school fire alarm is going off.



Possible inferences

: 

The school is on fire.



We are having a fire drill.



A student pulled the fire alarm.

 These are all logical explanations for why the fire alarm is going off.

Group Practice

 List some observations and inferences about the following picture.

Individual Practice

 On your notes, please write down 2 observations and 2 inferences about the following picture.

Write 3 observations and 3 inferences on your exit slip for the picture below.