Observation vs. Inference
You see that a plant has yellow leaves. Is this an observation or inference?
Observation
“The flower is purple.” Qualitative or quantitative?
Qualitative
You observe dark clouds in the sky. What is one reasonable inference?
It may rain soon.
Which is an observation: “The candle is lit” OR “Someone lit the candle five minutes ago”?
The candle is lit.
What type of observation uses descriptions such as color, smell, texture, or shape?
Qualitative
You say, “The dog is hungry because it is standing by its food bowl.” Observation or inference?
Inference
“The pencil is 14 cm long.” Qualitative or quantitative?
Quantitative
You see an empty plate with crumbs on it. What is one reasonable inference?
Someone ate food from the plate
Which is quantitative: “The book is heavy” OR “The book has a mass of 2 kg”?
The book has a mass of 2 kg.
What type of observation uses numbers or measurements?
Quantitative
“The liquid is bubbling.” Observation or inference?
Observation
“There are 6 fish in the tank.” Qualitative or quantitative?
Quantitative
A student walks into class with wet hair and a wet jacket. What is one reasonable inference?
It is probably raining outside / the student was out in the rain.
A scientist writes, “The powder is white, feels grainy, and has a mass of 12 g.” How many qualitative observations are included?
2 — white and grainy
What is the main difference between an observation and an inference?
An observation is something you notice using your senses or measurements; an inference is an explanation based on observations
“The liquid is bubbling because it is boiling.” Observation or inference?
Inference
“The rock feels rough and has shiny spots.” Qualitative or quantitative?
Qualitative
A plant’s leaves are wilted and the soil feels very dry. What is one reasonable inference?
The plant may need water.
A student says, “The metal feels warm, so it must have been sitting in the sun.” Identify the observation.
The metal feels warm.
Change this qualitative observation into a quantitative observation: “The water is hot.”
Answers vary: “The water is 80°C.”
A student says, “The ground is wet, so it must have rained.” Which part is the inference?
"It must have rained"
“The water is blue, clear and has a temperature of 22°C.” Does this contain qualitative or quantitative observations?
Both
Two identical ice cubes are placed in different locations. One melts much faster than the other. What is one reasonable inference?
The faster-melting ice cube was in a warmer location.
A scientist records: “The liquid changed from clear to blue after 30 seconds.” Identify one qualitative AND one quantitative observation.
Qualitative: changed from clear to blue. Quantitative: 30 seconds.
A student says, “The cup contains 100 mL of blue liquid, so I think someone added food coloring.” Identify the quantitative observation, qualitative observation, AND inference.
Quantitative: 100 mL. Qualitative: blue. Inference: someone added food coloring.