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Healing with Therapeutic Touch. The Placebo Effect A placebo is an inactive substance or ineffective practice that a person believes to be real. A person could find relief just because they believe in the power of the placebo!
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Healing with Therapeutic Touch • The Placebo Effect • A placebo is an inactive substance or ineffective practice that a person believes to be real. • A person could find relief just because they believe in the power of the placebo! • The Placebo Effect is a variation on Confirmation Bias, where a person’s expectations or beliefs influence experimental results.
Can science be biased? • “Women’s Brains” by Stephen J. Gould – 1980 • In the 1800’s, women didn’t have many rights & were discriminated against. • Paul Broca set out to prove men’s superiority by proving that women were less intelligent! • Gould took a 2nd look at Broca’s data & disproved his conclusions.
How can bias be removed from science? Scientists remove bias & error from their experiments by following the scientific method!
How Scientists Work • The Scientific Method • Scientists may solve problems, but the method may vary based on the problem!
Steps of the Scientific Method • Observe: make an observation of the world around you • Qualitative Observation: descriptive observation • Example: The plant is green. • Quantitative Observation: numerical observation • Example: The flask contains 12.45 mL.
The sky is blue. • Qualitative • Quantitative Qualitative!
There are 4 clouds. • Qualitative • Quantitative Quantitative!
There are 3 hills. • Qualitative • Quantitative Quantitative!
The 1st hill is small. • Qualitative • Quantitative Qualitative!
The clouds are small. • Qualitative • Quantitative Qualitative!
There are 38 birds. • Qualitative • Quantitative Quantitative!
Have you ever observed maggots on old meat? • 400 years ago, people believed that living things appeared spontaneously from nonliving matter (spontaneous generation)! • Francesco Redi, however, wanted to disprove this idea. • He considered it likely that flies laid eggs that were too small for people to see.
Steps of the Scientific Method 2. Ask a question:based on your observation, ask a question to investigate • Redi asked the question, “How do new living things, or organisms, come into being?” 3. Research:look in books, journals, & the internet to make additional observations & research about the questions you made from your observation
Steps of the Scientific Method 4. Formulate a Hypothesis: propose a scientific explanation to the question being observed & researched; at the end of the investigation, you will either accept or reject your hypothesis • The statement must be testable! • “Which is best?” does not lend itself to being tested! • Example: If meat is left uncovered, then flies will leave eggs on the meat, creating maggots.
Steps of the Scientific Method 5. Perform a Controlled Experiment: develop & use the experimental design to test your hypothesis • Whenever possible, the hypothesis should be tested by an experiment in which only 1 variable is changed at a time! • All other variables should be kept unchanged or controlled. Testing fertilizers on plant growth? Keep all other factors constant! The type of fertilizer should be the only thing changing!
Performing a Controlled Experiment • Redi created a controlled experiment in which only 1 variable was deliberately changed each time. • Redi was able to determine that when the gauze was not present, flies could reach the meat & maggots would appear. • When gauze was present, flies could not reach the meat & no maggots would appear.
Variables – the factors being tested • Controlled Variables: kept constant • Independent Variables: factor being manipulated (x-axis on a graph) • Dependent Variables: factor that responds (y-axis on a graph) • Control Group: the group where the independent variable is NOT applied (nothing is changed; used for comparison) Testing fertilizers on plant growth? IV: fertilizer used DV: plant growth CV: amount of sunlight, water, …
To remember independent vs. dependent variables – DRY MIX! Dependent Responding Y-axis Manipulated Independent X-axis
Redi’s Experiment • Independent Variable? ________________ • Dependent Variable? __________ • Controlled Variable? ________________________ • Control Group? _____________________ Cover on the jar Maggots Type of meat, size of jar, … No cover on the jar
Repeat your experiment! The more you perform your experiment, the more accurate your data & results will be!
Steps of the Scientific Method 6. Observe Again: collect data (measurements) & perform analysis on the data using graphs & charts
Steps of the Scientific Method 7. Draw Conclusions: state whether or not the evidence supports the hypothesis based on your data & analysis • Notice that we do not prove hypotheses! • Proof exists when the chance for error is 0. There is always some chance for error (no matter how small it is) & this existence of chance error means we cannot prove anything in true, honest, science!
Steps of the Scientific Method 8. Report back to the community: experimental results can be used by others to help them with their own experiments • This is what keeps science progressing! This is 1 way that bias is removed from science!
Hypothesis vs. Theory vs. Law • Hypothesis: possible explanation for a set of observations • Has not yet been thoroughly tested!
Hypothesis vs. Theory vs. Law • Theory: a well tested explanation that unifies a broad range of observations • A theory explains observations simply & clearly, & predictions can be made from them. • Widely accepted by the scientific community!
Hypothesis vs. Theory vs. Law • Law: a summary of observed natural events • Widely accepted by the scientific community! • They are less comprehensive than theories & normally are associated with a mathematical expression.