2 What is Science? “Science” derived from Latin ‘to know’ Way of asking and answering questions While studying the natural world around you.Seeking answers to questions about natural phenomena (we are therefore limited to what kinds of questions we ask)Scientific thinking reduces emotional reactions
3 Scientific DesignScientific knowledge begins with an observation and a proposed explanation.Introduction – Background information about your topicHypothesis- an ExplanationA hypothesis is testable and falsifiableIn science hypotheses are tested by using them to make predictions about how a particular system will behave
4 Method: The process of exactly how you preformed the experiment described in exhaustive detail. Results: Detailed charts, data tables and graphs that display your resultsConclusion: Detail analysis of your results, explain potential errors
6 Does it work? Scientific Method is a tool. Does this tool work? Life expectancyMortality ratesAre there better tools?
7 Scientific Method in Action We use the scientific method in everyday lifeExample:You got in your car to drive up here and turned the key but the car wouldn’t start (observation)
8 Scientific Method in Action Example:You got in your car to drive up here and turned the key but the car wouldn’t start (observation)Hypothesis: There is something wrong with the car
9 Scientific Method in Action Example:You got in your car to drive up here and turned the key but the car wouldn’t start (observation)Hypothesis: There is something wrong with the carHypothesis: battery dead, ignition problem,out of gas
10 Scientific Method in Action Test predictions (Method): turn on headlights, check spark plug wires, dip stick in gas tank
11 Scientific Method in Action Test predictions: turn on headlights, check spark plug wires, dip stick in gas tankAnalyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half full
12 Scientific Method in Action Test predictions: turn on headlights, check spark plug wires, dip stick in gas tankAnalyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half fullConclusion: gauge inaccurate, out of gas
13 Example Hyp: King’s collar repels fleas Pred: dogs wearing King’s collar will have fewer fleas than those without collarIV: King’s collar DV: presence of fleasCV’s: anything that might effect the number of fleas on the dogsCan we think of some???
14 Experimental DesignObtain 500 dogs of various breeds from local shelters. Have vet weed out the 200 dogs with the most fleas. Randomly assign individuals to 2 groups.Board the dogs in identical environments and treat them the same except that one group gets to wear the King collar and the other group does notAfter 2 wks. The dogs are examined by a vet for fleas.
15 Results: the dogs wearing the King collars were virtually free of fleas after the 2 wk period compared to the dogs without the collars which had about the same number of fleas as when the experiment began
16 Instrument: the object or survey that helps you collect data to be analzed. Important terms:
17 Important terms:Sample: a chosen population to represent a scientific study.- Example: LHS students, Men, Asians- Use common sense when choosing a sample-Random sampling- Each member of the population has an equal chance of being selected. (best sample)Experimental group: group(s) subjected to the independent variableControl group: group not subjected to the independent variable, used as measuring stick
18 Reproducibilityreproducibility: producing the same result consistently to verify result. It is therefore important to describe your experimental design in enough detail for others to perform the same experiment.A successful Experiment is repeatable.By anyone.Examples:Cold Fusion (1989)Ecstasy (Science, 2003)
19 Incorrect assumptions invalidate an experiment! Assumptions: factors thought to be true for the investigation but have not been verified or controlledCommonly accepted informationThought to be held constant but not controlledFactors beyond the investigators control because of technical or time considerationsIncorrect assumptions invalidate an experiment!
20 Statistics:Statistics – using mathematics to organize, summarize, and interpret numerical dataMean: arithmetic average of scoresVariability = how much scores vary from each other and from the mean