Jolene is a Registered Nurse (RN). After taking time off to have her first child she returned to work. She observed that she had migraines of varying severity every time she worked a twelve hour shift. She was able to fight through the migraines and do her job, but it was difficult, painful, exhausting, and possibly dangerous.
Jolene wondered what was causing the migraines. To answer this question she gathered available knowledge from friends and co-workers, the internet, and her health care provider. These sources gave many possible reasons for migraines. Jolene had taken science courses in preparation for nursing school, so she knew the best way to determine the cause was to use the scientific method. She evaluated the list and eliminated the possible test conditions that didn’t apply or that she couldn’t change:
|Possible Cause||Reasoning||Readily Testable?|
|Dehydration||she rarely had time to stop for water during shift||Yes|
|Caffeine withdrawal||she drank coffee at work||No|
|Changes in hormone levels||she was breastfeeding, but didn’t want to stop||No|
|Changes in sleep patterns||she did go to bed and get up earlier for shifts||Yes|
|Drinking alcohol||she didn’t drink||No|
|Exercise or other physical stress||on her feet 12 hours, but no control of that||No|
|Loud noises or bright lights||the hospital lights are bright, but no control||No|
|Missed meals||she often didn’t have time to eat meals on shift||Yes|
|Odors or perfumes||no control of the hospital smells||No|
|Smoking or smoke exposure||not in the hospital||No|
|Stress and anxiety||definitely, not much control||No|
|Certain foods||she missed meals, but didn’t eat different foods||No|
Each of the three variables remaining on the list could be tested, so each one could be used in a hypothesis. One-by-one Jolene would hypothesize that a test condition was the cause and then test the hypothesis by changing only that one condition and observing how it affected her migraine. For example her first stated hypothesis could be: dehydration is contributing to my migraines. Her first test could be to stay well hydrated and observe how it affected her migraines. Sometimes it’s easier to compare results with a null hypothesis, which in this case would be: hydration level does not affect my migraines.
Jolene realized that more than one variable could be contributing to her migraines, and that changing one might only affect the severity of her migraines rather than prevent them, so she needed to do more than just observe, she needs to make a measurement of migraine severity. She decided to use the Wong-Baker 1-10 Pain Scale as her measurement tool (instrument). She calibrated the scale with childbirth on the top, no pain on the bottom, and stepping on a Lego in the middle.
Finally, Jolene decided she would make multiple tests of each hypothesis by rotating through them. One week she made sure to drink more water, the next week she made sure to go to bed and get up at the same time every day, and finally she made sure to have quick foods ready for breaks. Jolene repeated the cycle for nine weeks, and kept track of her data in a table. To analyze the data she and added up the pain scores for the three shifts each week and put those results into a table.
|Test Condition||Week 1||Week 2||Week 3||Week 4||Week 5||Week 6||Week 7||Week 8||Week 9||Total|
Finish analyzing Jolene’s data by adding up the pain values for each test condition and filling in the total column on the right. Based on the results of Jolene’s test, what conclusion do you make about which variable is most likely making the largest contribution to her migraines?
Just as we saw from Jolene’s example, the basic scientific method is: Observe, ask a question, formulate a hypothesis, use the hypothesis to make a testable prediction, test the prediction experimentally, analyze results, compare prediction to test result, and formulate a conclusion.
This example is based on actual events, but names have been changed. The real-life Jolene concluded that a consistent sleep schedule was the most important factor. She then committed to getting up every day at the same early time as she did on works days, even if she didn’t have work. After about three weeks her migraines leveled out at about one low-severity migraine per month.
Most of the information that we use in this textbook, from the amount of force that bones can support to the amount of energy contained in various foods, was determined by scientists using the scientific method, but maybe not in exactly the same way that you learned in middle school.