Science

• Everything we know went through a testing process – Experimental Design, Scientific

Process, Scientific Method

Observation vs. Inference

Observation: can be made with only the five senses (sight, touch, hear, taste, and

smell)

Observations not guesses, assumptions or opinion.

Inference: logical assumption based off of prior knowledge or after very limited

observation

ObservationsTwo types of observations:

– Qualitative observation• descriptions • observed (not measured) • Ex. Colors, textures, smells, tastes, appearance, etc. • Qualitative → Quality

– Quantitative observation• numbers • measured • Ex. Length, height, area, volume, weight, speed, time,

temperature, humidity, sound levels, etc. • Quantitative → Quantity

Observation or Inference?

• It is blue.

Observation or Inference?

• It is old.

Observation or Inference?

• It must be a ball.

Observation or Inference?

• There are 9 tentacles.

Hypothesis• Educated prediction made from various

observations- It is NOT guess! • Useful only if it can be tested.

• If I do this (manipulated variable), then I think this will happen (responding variable) because………

The Experiment: experimental design

• Setting up an experiment– Control group (generally what is “normal”)• Controlled variables

– Experimental group• Variables: –Manipulated variable (independent variable)– Responding variable (dependent variable)

Why only have one manipulated variable per experiment?

Data collection

• Large sample size• Use of a data table– Variables easy to identify– Measurable results

• Outliers can cause data distortion– How can you recognize outliers?

• Multiple trials give most accurate results

• After an experiment is complete:– Results, more testing, new hypotheses, more experiments, more results…

and on and on

– work is usually published– Peer review process- Experiments must be successfully repeated by other

scientists– After many years, after many scientists, lots of supporting evidence, new

theories are accepted

Atomic Theory Cell theory Germ Theory

Theory vs Law

• Law– Explains one topic– No longer adding evidence to laws

• Theory– Explains a multiple hypotheses– Unifies evidence from multiple studies– Continually adding evidence to theories