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!

The Scientific Method

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 Cover on the jar Independent Variable? ________________ Dependent Variable? __________ Controlled Variable? ________________________ Control Group? _____________________ 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 normally are associated with a mathematical expression.