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

Two 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 Theory Explains one topic No longer adding evidence to laws Theory Explains a multiple hypotheses Unifies evidence from multiple studies Continually adding evidence to theories