Direct Observation vs Interference

Contributed by:
Jonathan James
The highlights are:
1. Observations- Qualitative and Quantitative
2. Interference
3. Compare and Contrast
1. Observations vs. Inferences
“You can observe a lot just by watching.”
-Yogi Berra
2. • An observation is the gathering of information
by using our five senses:
 Sight
 Smell
 Hearing
 Taste
 Touch
• There are two types of observations
 Qualitative
 Quantitative
4. Qualitative Observations
• Qualitative observations describe what we
• “Qualitative” = quality (descriptive)
• These observations use adjectives to describe
• Example: The flower has white petals.
• Example: Mr. M has blue eyes.
5. Qualitative Observations
6. Quantitative Observations
• Quantitative observations measure what we
• “Quantitative” = quantity (numerical)
• These observations use numbers to measure
something in a quantitative way.
• Example: The flower has seven petals.
• Example: Mr. M has two eyes.
7. Quantitative Observations
8. Side by Side Comparison
9. Which is better?
• Both types of observations are valuable in
science. In an experiment though, quantitative
observations can be precisely and objectively
Qualitative: The road is long. (describes)
Quantitative: The road is 5 km long. (measures)
• Some things are easier to quantify than others.
Scientists use innovative ways of turning
qualitative into quantitative.
10. Which is better?
• For example, someone might say that a dead
fish is smelly.
• It is hard to know just how smelly the fish is
• To make this quantitative, the scientist could
ask the person to rate the “smelliness” on a
scale of 1-5.
• This would then allow you to compare how
smelly the fish is!
12. • Inferences are an explanation for an
observation you have made.
• They are based on your past experiences and
prior knowledge.
• Inferences are often changed when new
observations are made.
• Again, observations are information we gather
directly through our five senses….inferences
help explain those observations!
13. Here are some examples!
• 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. They are all based on prior
experiences. We have all seen rain, sprinklers,
morning dew, and dogs going to the bathroom.
14. Here are some examples!
• 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.
• Again, these are all logical explanations for why
the fire alarm is going off.
15. You Try!
• Observation: A student is sitting in the main
• Possible inferences:
Why might a student be sitting there?
17. Compare and Contrast
Observations Inferences
• That plant is extremely • That plant is extremely
wilted. wilted due to a lack of
• The car stopped running
• The car stopped running. because it was out of gas.
• The Red’s are leading
• The Red’s are leading there division because
there division. they are playing well right
18. Note the Difference.
• In laboratory exercises, record observations
NOT inferences
• Observations are used to summarize
• Inferences may be used when writing the
conclusion in your lab
• Inferences are used to explain