Presentation on theme: "Activity 2: The Pellagra Story"— Presentation transcript:
1Activity 2: The Pellagra Story Challenge:What are the common methods of scientific problem solving?White spaceHow do you think doctors determine the cause of a disease?Introduction:Video and notes on videoVocabulary:Evidence, observation, inference, tradeoff, ethicsMaterials:√Procedure:√Data:1 Student Sheet 2.2,1 Student Sheet 2.3,Analysis:AQ 1, AQ 2b, 4, 5, 6
2What are some possible causes of diseases? 1Imagine that doctors are observing a new disease, and they don’t know what causes it.What are some possible causes of diseases?What kinds of things would scientists do to learn more about a disease and its cause or causes?Read the Analysis questionsWatch the Video clip on pellagra one time, just listening carefully.Watch the Video clip on pellagra again, taking notes on handout student sheet 2.12odys08_vid_pellagra_350.mov
3Analysis Questionsa. What was the first step in Dr. Goldberger’s research into pellagra? Explain whythis step was important in developing his hypothesis.b. During this first step in his research, what evidence did Dr. Goldbergerfind that suggested that pellagra was not caused by germs?2. b. What did he do to provide evidence of the relationshipbetween pellagra and nutrition? Be sure to explain how his research providedevidence that supported or disproved his hypothesis.
4Analysis QuestionsCompare the steps of the traditional scientific method to the steps Dr. Goldberger followed to investigate pellagra. How were the steps the same? How were the steps different?Fill in the “After” column for statements 3 and 4 only on Sheet 1.1, “Anticipation Guide: Ideas about Experimental Design.”Did your thinking change?6. To investigate his hypothesis, Dr. Goldberger had prisoners volunteer to be fed a poor diet; asa result, 7 out of 11 prisoners developed pellagra.What do you think about Dr. Goldberger’s decision to experiment on people?Support your answer with evidence and identify the trade-offs of your decision. Hint: To writea complete answer, first state your opinion. Provide two or more pieces of evidence thatsupport your opinion. Then consider all sides of the issue and identify the trade-offs of yourdecision.
5What was the problem of pellagra? In 1914, pellagra was a common disease in the United States. It caused rashes, insanity and death.What did people think caused pellagra?1. Eating corn2. An insect3. Bacteria/germs4. Lack of nutrition/poor dietWhat evidence did Dr. Goldberger observe or collect about pellagra?Pellagra was common in the South, particularly in poor areas and institutions (such as mental hospitals, orphanages, and prisons).Many people in the South ate a poor diet, consisting of cornbread, fatback (pork), and syrup.Staff at institutions (such as mental hospitals, orphanages, and prisons) did not have pellagra.Orphans provided with fresh vegetables, meat, and milk either recovered from pellagra or did not get it.Some prisoners fed a poor diet developed pellagra. When provided a better diet, they recovered.What did Dr. Goldberger conclude about the cause of pellagra?Dr. Goldberger concluded that pellagra was caused by a nutritional deficiency (poor diet).
6Take out your Vocabulary Log Observation: Any description or measurement gathered by the senses Inference: A conclusion, or the process of developing a conclusion based on evidence.
7Why do you think the presenter made this comment? 3In the video clip, one of the presenters comments that the fact that orphans provided with fresh vegetables, meat, and milk either recovered from pellagra or did not get it “was not scientific evidence.”Why do you think the presenter made this comment?Do you agree with the presenter? Why or why not?
9Key to Student Sheet 2.2, “Observations and Inferences” Identify each of the following statements as either an observation or an inference that was made about pellagra.Observation Inference___ X* Corn causes pellagra.X ___ Only children in the orphanage developed pellagra. The staff did not.X ___ Changing the orphans’ diet cured those who had pellagra.X ___ Only people who lived in the South got pellagra.___ X Pellagra is not an infectious disease.X ___ Pellagra causes skin rashes and, eventually, insanity.___ X* People get pellagra because they are poor.___ X Pellagra is caused by diet.X ___ Orphans and prisoners who ate a balanced diet did not develop pellagra.___ X* The Southern way of life caused pellagra.Look at the statements that you marked as inferences. Based on the evidence that Dr. Goldberger found, put a star next to each inference that is faulty.Choose one of the inferences that you put a star next to, and explain how that inference could havebeen made based on observations.
10The Pellagra Story: Dr. Goldberger and the Traditional Scientific Method Steps of the traditional scientific methodSame or different?Steps taken by Dr. GoldbergerState the Problem or QuestionSameDr. Goldberger was presented with the problem "What causes Pellagra?" when asked to investigate.Propose an explanation (hypothesis)SameDr. Goldberger hypothesized that an inadequate diet causedpellagra.Collect Evidence(experiment)SameDr. Goldberger fed orphans a balanced diet and observed it'seffect on PellagraAnalyze dataSameDr. Goldberger recorded and analyzed data about orphansDraw conclusions, and if necessary,revise and repeatDifferentDr. Goldberger did not draw a final conclusion after his investigation with the orphans. He obtained more evidence by conduction an experiment with prisoners.
11Analysis Question 1a1. a. What was the first step in Dr. Goldberger’s research into pellagra? Explain why this step was important in developing his hypothesis. The first thing that Dr. Goldberger did was to visit sites where pellagra was prevalent. He focused on the southern United States and visited institutions such as orphanages and prisons. He conducted this background investigation before forming any hypothesis for the cause of pellagra. This was an important step in developing his ideas. It was during this initial period that Dr. Goldberger observed common factors (such as poverty and diet) linked to pellagra and therefore hypothesized that pellagra may be a nutritional deficiency (poor diet). These are often overlooked elements of scientific study and are usually essential to the development of strong hypotheses.
12Analysis Question 1bDuring this first step in his research, what evidence did Dr. Goldberger find that suggested that pellagra was not caused by germs?Dr. Goldberger’s observations about the prevalence of pellagra among poor and institutionalized people provided some evidence that pellagra did not occur randomly.He pointed out that staff at institutions where pellagra was common did not have it, while many of the patients did. This provided some evidence that pellagra was not an infectious disease, since victims did not transmit it to the staff.
13Scoring GuideLEVEL DESCRIPTION Level 4 Student accomplishes Level 3 and goes beyond in some Above and beyond significant way, such as: questioning or justifying the source, validity, and/or quantity of evidence. Level 3 Student identifies key evidence with the appropriate facts, data and Complete and correct observations. Level 2 Student includes some, but not all, relevant evidence Almost there BUT student omits key evidence OR provides an insufficient number of facts, data, and observations. Level 1 Student states opinion as facts On your way OR student uses incorrect or irrelevant evidence. Level 0 Student’s response is missing, illegible, or irrelevant. X Student had no opportunity to respond.
14Writing Frame – Recognizing Evidence I am investigating the following question: _____________________________________________________________________________________________________________I have found the following facts, data, and observations that provide evidence aboutthis question:1. _________________________________________________________________________________________________________________________________________________________________________________________________________
15Analysis Question 2bWhat did he do to provide evidence of the relationship between pellagra and nutrition?Be sure to explain how his research provided evidence that supported or disproved his hypothesis.He observed that people who worked in institutions did not get pellagra but their patients did.He observed that the orphans with pellagra who were fed a complete diet got better.He observed that when orphans who did not have pellagra and were fed a complete diet they did not get it.He did an experiment in which he fed Prisoners a poor diet; as a result, 7 prisoners developed pellagra.He did another experiment in which then fed those patients a better diet and they got better..
16Analysis Question 4Compare the steps of the traditional scientific method to the steps Dr. Goldberger followed to investigate pellagra.How were the steps the same? How were the steps different?Use Student Sheet 2.3 to help you.
17Analysis question 5Fill in the “After” column for statements 3 and 4 only on Sheet 1.1, “Anticipation Guide: Ideas about Experimental Design.”Did your thinking change? Explain why or why not.
18Analysis Question 6To investigate his hypothesis, Dr. Goldberger had prisoners volunteer to be fed a poor diet; as a result, 7 out of 11 prisoners developed pellagra. What do you think about Dr. Goldberger’s decision to experiment on people? Support your answer with evidence and identify the trade-offs of your decision. Hint: To write a complete answer, first state your opinion. Provide two or more pieces of evidence that support your opinion. Then consider all sides of the issue and identify the trade-offs of your decision.