Documents about Convincing Evidence
06_054x
UPenn, VHM 801
Excerpt: ... Supplementary exercise 6.54 of IPS5e - A farmer "recognizes" water in 4 trials out of 5. (a) The hypothesis of interest is H0: p=0.5 against the alternative Ha: p>0.5. (It is difficult to imagine that p<0.5, unless there is some error in the experiment or the farmer messes up.) (b) Assuming independence between trials, and same probability p of getting it right (water or not), this is a binomial setting. Therefore X = number of correct answers follows B(5,p), in particular B(5,0.5) if the farmer is guessing. (c) Observed value x=4. The test statistic is simply X. Critical values are large (larger than the expected value 2.5 under H0). Therefore, P-value = P(X>=4) = P(X=4) + P(X=5) = 5*0.5^4*(1-0.5) + 0.5^5 = 0.1875 The outcome x=4 is not significant at the 5%- or 10%-level. Conclusion: There is no convincing evidence that the farmer does better than pure guessing. You will have noted that the model and testing procedure is ...
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06_067
UPenn, VHM 801
Excerpt: ... Exercise 6.67 - A farmer "recognizes" water in 4 trials out of 5. (a) The hypothesis of interest is H0: p=0.5 against the alternative Ha: p>0.5. (It is difficult to imagine that p<0.5, unless there is some error in the experiment or the farmer messes up.) (b) Assuming independence between trials, and same probability p of getting it right (water or not), this is a binomial setting. Therefore X = number of correct answers follows B(5,p), in particular B(5,0.5) if the farmer is guessing. (c) Observed value x=4. The test statistic is simply X. Critical values are large (larger than the expected value 2.5 under H0). Therefore, P-value = P(X>=4) = P(X=4) + P(X=5) = 5*0.5^4*(1-0.5) + 0.5^5 = 0.1875 The outcome x=4 is not significant at 5%- or 10%-level. Conclusion: There is no convincing evidence that the farmer does better than pure guessing. You will have noted that the model and testing procedure is identical to the taste testing example from lectu ...
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Lecture25
Iowa State, STAT 104
Excerpt: ... both bigger than 10. Note the text says bigger than 5 but we are going to be cautious. 9 3 Stat 104 Lecture 25 Inference for Binomial p Population Parameter? Population p Inference Sample ^ p Sample Statistic 10 Inference Propose a value for the population proportion, p. Does the sample data support this value? 11 Example Are non-whites under-represented on juries in Story County? 12 4 Stat 104 Lecture 25 Example According to the U.S. census, Story County has 9.7% of its population classified as non-white. 13 Example Population: All people eligible for jury duty in Story County. Parameter: Proportion of all people eligible for jury who are nonwhite. 14 Example For a random sample of 120 people called for jury duty in Story County only 3 are non-white. Is this convincing evidence of underrepresentation of non-whites? 15 5 Stat 104 Lecture 25 Step 1- Set-Up State your null and alternative hypotheses and define p. H0: p = 0.097 HA: p < 0.097 p is the proportion of ...
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06_070x
UPenn, VHM 801
Excerpt: ... he 5%- or 10%-level. Conclusion: There is no convincing evidence that the farmer does better than pure guessing. You will have noted that the model and testing procedure is identical to the taste testing example from lecture 6L. ...
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06_054x
UPenn, VHM 801
Excerpt: ... 5%- or 10%-level. Conclusion: There is no convincing evidence that the farmer does better than pure guessing. You will have noted that the model and testing procedure is identical to the taste testing example from lecture 6L. ...
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day17
Cal Poly, STAT 218
Excerpt: ... Stat 218 - Day 17 One-Tailed t-test Recall from yesterday that we introduced the general idea of a hypothesis test and the specific details of a two-sample t-test: Null hypothesis, denoted by H0, typically a statement of no effect or no difference o In this case: H0: A=B Alternative hypothesis, denoted by HA, also called the research hypothesis o In this case: HA: AB Test statistic, which is a measure of how consistent the observed sample data are with the null hypothesis (y yB ) 0 o In this case: t s = A 2 2 s A sB + n A nB P-value, which is the probability of obtaining such an extreme test statistic if the null hypothesis were true o The smaller the P-value, the stronger the evidence against the null hypothesis o P-values less than .05 are generally considered to be moderately convincing evidence against H0; P-values less than .01 are generally considered to be strongly convincing evidence against H0. o In this case: P-value = area in tails of t-distribution be ...
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Chapter21
University of Montana, MATH 444
Excerpt: ... Chapter 21 More About Tests The P-value is a measure of the strength of the evidence against the null hypothesis and in favor of the alternative hypothesis. How small a P-value is convincing evidence that the alternative hypothesis is true? It depends on the context how much you believe the null hypothesis to begin with, what are the costs if you make a mistake. It would probably take a much smaller P-value to convince you that someone had ESP than to convince you that someone wasnt guessing on a multiple-choice test. However, sometimes we set a threshold for what constitutes convincing evidence . If the P-value falls below the threshold, then the result is said to be statistically significant. The threshold is sometimes denoted as (alpha) and is called the significance level. Common values are .10, .05 and .01. If the P-value is less than .05, for example, the result is said to be statistically significant at the .05 level. We may also say, we reject the null hypothesis in favor of the alternative h ...
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mid_summ
Duke, STA 240
Excerpt: ... vincing evidence that heavy sleepers have lower predation than light sleepers (one sided p-value = 0.1576, Wilcoxon rank sum test) while there is strong but inconclusive evidence that heavy sleepers have lower danger index than light sleepers (one sided p-value = 0.0208, Wilcoxon rank sum test) and strong evidence that heavy sleepers have a lower sleep exposure index than light sleepers (one sided p-value = 0.003, Wilcoxon rank sum test). There is not convincing evidence that heavy sleepers spend a larger fraction dreaming than light sleepers (one sided p-value = 0.3917, two sample t-test, t = 1.684, df 40). The mean percent of dreaming is estimated with 95% confidence between -0.04 + percent greater in heavy sleepers than light sleepers. See table 2 for a summary of the tests conducted. Conclusions: Since this is a non-random observational study the results are associated to the specific study and thus not able to establish causality or to generalize the findings to the population of heavy and light s ...
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Lecture26
Iowa State, STAT 101
Excerpt: ... Stat 101 Lecture 26 Interpretation Getting a value of the sample proportion of 0.12 is consistent with random sampling from a population with population proportion p=0.10. This sample result does not contradict the null hypothesis. The P-value is not small, therefore fail to reject H0. 1 Interpretation Even though the sample proportion, 0.12, is larger than the hypothesized population proportion, 0.10, it is not large enough for us to believe that the population proportion is greater than 0.10. Its not convincing evidence . 2 Conclusion Based on this sample, the law firm should not pursue the class action lawsuit because the population proportion of defective cars could be only 10%. 3 Stat 101 Lecture 26 Test of Hypothesis Step 1: State your null and alternative hypotheses. H0: p = po HA: p > po 4 Test of Hypothesis Step 2: Check conditions Independence Random sampling condition 10% condition Success/Failure condition 5 Test of Hypothesis Step 3: ...
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Lecture29
Iowa State, STAT 101
Excerpt: ... Stat 101L: Lecture 29 Interpretation Getting a value of the sample proportion of 0.12 is consistent with random sampling from a population with population proportion p = 0.10. This sample result does not contradict the null hypothesis. The P-value is not small, therefore fail to reject H0. 1 Interpretation Even though the sample proportion, 0.12, is larger than the hypothesized population proportion, 0.10, it is not large enough for us to believe that the population proportion is greater than 0.10. There is not convincing evidence . 2 Conclusion Based on this sample, the law firm should not pursue the class action lawsuit because the population proportion of defective cars could be only 10%. 3 1 Stat 101L: Lecture 29 Test of Hypothesis Step 1: State your null and alternative hypotheses. H0 : p = po HA: p > po 4 Test of Hypothesis Step 2: Check conditions Independence Random sampling condition 10% condition Success/Failure condition 5 Test of Hypothesis Step 3: Calculate the test statistic value an ...
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Week1Example
Cal Poly, STAT 217
Excerpt: ... Spring, 2009 Stat 217 Week 1 Example Monday, April 6 In a 2005 study published in Science (Todorov, Mandisodza, Goren, and Hall) participants were shown pictures of two candidates and asked who has the more competent-looking face. Researchers then predicted the winner to be the candidate whose face was judged to look more competent by most of the participants. For the 32 U.S. Senate races in 2004, this method predicted the winner correctly in 23 of them. (a) What are the observational units in this study? (b) What is the variable of interest in this study? (c) Sketch a well-labeled graph to visually represent the results of this study and write a one-sentence summary of the results. (d) What is the parameter of interest in this study? (e) What is the statistic in this study? (f) What is the null hypothesis in this study? (g) How would you set up the "coin tossing applet" as in Lab 1 to determine whether there is convincing evidence that this method appears to correctly predict the winner of the election ...
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how to write a book review
Pitt. State, HISTORY 101
Excerpt: ... the paper, identify the author briefly.) Describe the author's viewpoint and purpose for writing the book; note any aspects of the author's background that are important for understanding the topic he or she writes about. Note the most important evidence the author presents to support his or her thesis, or argument. Evaluate the author's use of evidence, and describe how the author deals with the counterevidence. (Is the book's argument convincing?) Compare this book with other books or articles you have read on the same subject. 2 Conclude with a final evaluation of the book. You might discuss in your review who would find this book useful and why. NOTE: Critical does not mean negative. If a book is well written and presents an original thesis supported by convincing evidence , say so. A good book review does not have to be negative; it does, however, have to be fair and analytical. 3 ...
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TestMeanHW3
Iowa State, STAT 401
Excerpt: ... Stat 401 HW3 Question 2 in JMP Note that the data set I use here is similar, but not the same as the data in the HW. Enter the data into JMP (again, this is NOT the HW data, but simply something very similar with a few values changed). Now, set up your hypothesis. In this case, we are testing H o : = 15% vs. H a : 15% . We are going to do a "Test Mean" function within Analyze Distribution. o First, get to Analyze Distribution o Now, in the output window, click the up-side-down triangle and come down to the "Test Mean" option o In this case, we are testing if the mean is 15oz ( H o : = 15% ) o After clicking OK, JMP creates the following output either at the bottom or the right side of the output window o Hence, in this case, we have a two sided p-value of 0.3324. Thus, we have failed to find significant evidence against H o : = 15% . In other words, we have not found convincing evidence that the amount of K20 in the fertilizer is different from 15%. ...
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Assignment8
Cornell, BIO 221
Excerpt: ... BioNB 221 Fall 2008 Discussion Section Assignment 8 Plant behavior Before completing this assignment, please do the reading for next weeks section: Karban, R. 2008. Plant behavior and communication. Ecology Letters, 11, 727-739. Based on the information from this reading, do you think plants behave? If so, what do you think is the most convincing evidence that plants behave? What tools, theories, or concepts we have developed in this course can be applied to understand this behavior in plants? If not, what is fundamentally different about plants as compared to animals that makes them unable to behave? What do we lose by trying to study plants with a behavioral framework designed primarily for animals? Please keep your assignment between 2 and 3 typed, double-spaced pages. Please submit your assignment by email to mkk29@cornell.edu before your section on 12/2/08, or bring a hard copy with you to section. ...
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quiz17b
Penn State, STAT 100
Excerpt: ... Quiz #17 Write name, ID You have a suspicious coin. You flip this coin 400 times and observe 160 heads. You want to set up a statistical hypothesis test to determine whether this is convincing evidence that the coin is weighted unfairly. Show how to calculate the test statistic. You do not have to do the math; just set it up. ...
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quiz16b
Penn State, STAT 100
Excerpt: ... Quiz #16 Write name, ID You have a suspicious coin. You flip this coin 400 times and observe 160 heads. You want to set up a statistical hypothesis test to determine whether this is convincing evidence that the coin is weighted unfairly. Show how to calculate the test statistic. You do not have to do the math; just set it up. ...
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Pease_App_1.3
UVA, CAT 3
Excerpt: ... ing. Be prepared to discuss each essay in the packet and your reactions/thoughts. Questions over the weekend? Feel free to email me! pease_spms@yahoo.com Write down the title of the essay. Then give it a code: + = great choice for title = decent choice for title - = poor choice for title Title Lead (Introduction) Does the author capture the reader's attention at the beginning? How? Conclusion (ending) How does the author end the essay? How does this ending make you feel as a reader? How does the author's personality come across in the essay? Voice What is the author's attitude towards the topic s/he is writing about? How do you know? Tone How many paragraphs long is the essay? In your opinion, is it too long, too short, or just right? Why? Length Evidence used to support author's ideas Give an example, then rate on a scale of 1-10, with ten being the strongest, most convincing evidence . ...
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104require
Wisc Parkside, BIOS 104
Excerpt: ... relaxed and comfortable, but too often relies on notes. Visuals are used, but hard to see or are sloppy. Listeners are sometimes ignored or misunderstood. (2 pts) Max: 3 pts Content Exemplary The presentation is carefully organized and provides convincing evidence to support conclusions. (3 pts) The content is accurate and complete. Listeners are likely to gain new insights about the topic. (3-4 pts) The speaker is relaxed and comfortable, speaks without undue reliance on notes, and interacts effectively with listeners. Visuals are clear and easy to see by audience. (3 pts) Score Max: 4 pts Style Max: 3 pts (1 pt) Total Score: Catherine Mossman: Instructor GOAL (Reasoned Judgment): Analytical skills competence: Students will be able to correctly create and interpret graphs. Measurable outcome: Students will proficiently calculate and/or transcribe data to graphs using appropriate units, and accurately summarize the content of the graphs. Scoring Rubric: 5) Data are correctly calculated or transcribe ...
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asynchLGMsynth
Arizona, GEOS 582
Excerpt: ... heir moraines argument provides convincing evidence that this was in fact the case. It is harder to explain such a disconnect on a hemispheric scale, as Stott et al attempt unconvincingly to do. 1 ...
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Discussion_Guidelines
Washington, SIS 202
Excerpt: ... engage in section discussions by referring to the SIS 202 assigned materials with which we are all familiar. All of us draw from our personal experiences and feelings to understand course materials, often in productive and illuminating ways. However, productive discussion in this class must always be grounded in and engage with assigned readings. In order to clarify our confusion, it is necessary to think out loud and to ask peers for assistance at the point where our thinking becomes less clear. Thinking out loud is a risktaking activity that has great rewards. These rewards include the opportunity to resolve confusion, to strengthen analytical thinking skills, to strengthen your argument by testing it against other alternative interpretations, and to consider changing your position when others provide more convincing evidence or interpretations of course materials. In other words, do not be afraid to speak before you have fully developed your own argumentdiscussion is a process of thinking, not it ...
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S17
University of Texas, BIO 325
Excerpt: ... S1.Zickler was the first person to demonstrate gene conversion by observing unusual ratios in Neurospora octads. At first, it was difficult for geneticists to believe these results because they seemed to contradict the Mendelian concept that alleles do not physically interact with each other. However, work by Mary Mitchell provided convincing evidence that gene conversion actually takes place. She investigated three different genes in Neurospora. One Neurospora strain had three mutant alleles: pdx-1 (pyridoxine-requiring), pyr-1 (pyrimidine-requiring), and col-4 (a mutation that affected growth morphology). The pdx-l gene had been previously shown to map in between the pyr-1 and col-4 genes. As shown here, this strain was crossed to a wild-type Neurospora strain. pyr-1 pdx-1 col-4 pyr-1+ pdx-1+ col-4+ She first analyzed many octads with regard to their requirement for pyridoxine. Out of 246 octads, two of them had an aberrant ratio in which two spores were pdx-1 and six were pdx-1+. These same spores were the ...
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Lecture3_08_Handouts
Virginia Tech, BIOL 2104
Excerpt: ... participates in energy transfer in hundreds of cellular reaction But the most fundamental role of nucleotides is the storage and retrieval of biological information Macromolecules are by far the most abundant molecules in the cell 13 Macromolecules are built by covalently linking monomeric subunits into long chains, or polymers Monomers are added to the end of a growing polymer chain via a condensation reaction 14 In the early 20th century, chemists debated whether macromulecules really existed The invention of the ultracentrifuge by Theodor Svedberg helped collect convincing evidence that proteins are macromolecules Additional evindence came later in the 1930s from X-ray diffraction studies 15 Noncovalent bonds can add up to create a strong attraction between two molecules Small molecules form macromolecules, which, in turn, can assemble into large macromolecular complexes Homework - Read question and answer 2-8 - Question 2-16 - Question 2-20 - Question 2-21 16 ...
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Lecture19_040804
University of Texas, BIO 370
Excerpt: ... influence one another's evolution. This incorporates two phenomena : 1) coadaptation = a reciprocal relationship in which each species influences the fitness of the other and 2) cospeciation = the relationship has influenced similar speciation patterns, such that phylogenies of the co-evolved species are mirror images of each other. In order to provide convincing evidence that species have coevolved you must examine both phenomena. Coadaptation is usually supported by experimental evidence that suggests the relationship is crucial to the survival of both parties. Always strong inference, never conclusive proof (since we cannot replay evolutionary history). There are two main types of reciprocal coadaptations: mutualisms : a coadaptive relationship where two or more species experience increased fitness from mutual adaptations (both parties benefit) and BIO370 SPR 04 WEEKS LECTURE NOTES 19 APR 08 PG 2 of 3 antagonisms a coadaptive relationship where two or more species experience decreased fitness from mutua ...
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