Definition Of Comparison Error
Contents |
when considering a result under definition of comparison in math many hypotheses, some tests will give false
Definition Of Comparison Shopping
positives; many statisticians make use of Bonferroni correction, false discovery rate, and
Definition Of Comparison And Contrast
other methods to determine the odds of a negative result appearing to be positive. References[edit] ^ Benjamini, Yoav; Hochberg,
Definition Of Comparison For Kids
Yosef (1995). "Controlling the false discovery rate: a practical and powerful approach to multiple testing" (PDF). Journal of the Royal Statistical Society, Series B. 57 (1): 289–300. MR1325392. Retrieved from "https://en.wikipedia.org/w/index.php?title=Per-comparison_error_rate&oldid=672691707" Categories: Hypothesis testingRates Navigation menu Personal tools Not definition of comparison in literature logged inTalkContributionsCreate accountLog in Namespaces Article Talk Variants Views Read Edit View history More Search Navigation Main pageContentsFeatured contentCurrent eventsRandom articleDonate to WikipediaWikipedia store Interaction HelpAbout WikipediaCommunity portalRecent changesContact page Tools What links hereRelated changesUpload fileSpecial pagesPermanent linkPage informationWikidata itemCite this page Print/export Create a bookDownload as PDFPrintable version Languages Add links This page was last modified on 23 July 2015, at 06:40. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. Privacy policy About Wikipedia Disclaimers Contact Wikipedia Developers Cookie statement Mobile view
may be challenged and removed. (June 2016) (Learn how and when to remove this template message) An example of data produced by data dredging, apparently showing a close link between the letters in the winning word used in a spelling bee definition of comparison symbols competition and the number of people in the United States killed by venomous spiders. The definition of comparison operator clear similarity in trends is a coincidence. If many data series are compared, similarly convincing but coincidental data may be obtained. In definition of contextualization statistics, the multiple comparisons, multiplicity or multiple testing problem occurs when one considers a set of statistical inferences simultaneously[1] or infers a subset of parameters selected based on the observed values.[2] It is also known as https://en.wikipedia.org/wiki/Per-comparison_error_rate the look-elsewhere effect. Errors in inference, including confidence intervals that fail to include their corresponding population parameters or hypothesis tests that incorrectly reject the null hypothesis, are more likely to occur when one considers the set as a whole. Several statistical techniques have been developed to prevent this from happening, allowing significance levels for single and multiple comparisons to be directly compared. These techniques generally require a higher significance threshold for individual https://en.wikipedia.org/wiki/Multiple_comparisons_problem comparisons, so as to compensate for the number of inferences being made. Contents 1 History 2 Definition 2.1 Classification of multiple hypothesis tests 3 Example 4 Controlling procedures 5 Post-hoc testing of ANOVAs 6 Large-scale multiple testing 6.1 Assessing whether any alternative hypotheses are true 7 See also 8 References 9 Further reading History[edit] The interest in the problem of multiple comparisons began in the 1950s with the work of Tukey and Scheffé. New methods and procedures came out: the closed testing procedure (Marcus et al., 1976) and the Holm–Bonferroni method (1979). Later, in the 1980s, the issue of multiple comparisons came back (Hochberg and Tamhane (1987), Westfall and Young (1993), and Hsu (1996)). In 1995 work on the false discovery rate and other new ideas began. In 1996 the first conference on multiple comparisons took place in Israel. This was followed by conferences around the world: Berlin (2000), Bethesda (2002), Shanghai (2005), Vienna (2007), and Tokyo (2009). All these reflect increased interest in multiple comparisons.[3] Definition[edit] This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2016) (Learn how and when to remove this template message) In this context the term "comparisons" refers to comparisons of two groups, su
Calculate the Tukey HSD test Explain why the Tukey test should not necessarily be considered a follow-up test Many experiments are designed to compare more than two conditions. We will take as an example the case study "Smiles and Leniency." In this study, the effect of different types of smiles on the leniency http://onlinestatbook.com/2/tests_of_means/pairwise.html shown to a person was investigated. An obvious way to proceed would be to do a t http://www.businessdictionary.com/definition/contrast-error.html test of the difference between each group mean and each of the other group means. This procedure would lead to the six comparisons shown in Table 1. Table 1. Six Comparisons among Means. false vs felt false vs miserable false vs neutral felt vs miserable felt vs neutral miserable vs neutral The problem with this approach is that if you did this analysis, you would have six chances definition of to make a Type I error. Therefore, if you were using the 0.05 significance level, the probability that you would make a Type I error on at least one of these comparisons is greater than 0.05. The more means that are compared, the more the Type I error rate is inflated. Figure 1 shows the number of possible comparisons between pairs of means (pairwise comparisons) as a function of the number of means. If there are only two means, then only one comparison can be made. definition of comparison If there are 12 means, then there are 66 possible comparisons. Figure 1. Number of pairwise comparisons as a function of the number of means. Figure 2 shows the probability of a Type I error as a function of the number of means. As you can see, if you have an experiment with 12 means, the probability is about 0.70 that at least one of the 66 comparisons among means would be significant even if all 12 population means were the same. Figure 2. Probability of a Type I error as a function of the number of means. The Type I error rate can be controlled using a test called the Tukey Honestly Significant Difference test or Tukey HSD for short. The Tukey HSD is based on a variation of the t distribution that takes into account the number of means being compared. This distribution is called the studentized range distribution. Let's return to the leniency study to see how to compute the Tukey HSD test. You will see that the computations are very similar to those of an independent-groups t test. The steps are outlined below: Compute the means and variances of each group. They are shown below. Condition Mean Variance False 5.37 3.34 Felt 4.91 2.83 Miserable 4.91 2.11 Neutral 4.12 2.32 Compute MSE, which is simply the mean of the variances. It is equal to 2.65. Compute for each pair of means, where Mi is one mean, Mj is the other mean, and n is the number of scores in each
Sign Up Subjects TOD contrast error Definition + Create New Flashcard Popular Terms In interview or performance appraisal process, error caused by the effect of previously interviewed or appraised applicants on the interviewer. It results in a conscious or subconscious comparison of one applicant with another, and tends to exaggerate the differences between the two. dislocated work... organizational... technical skill job specificati... motivation values job design recruitment human resource... You Also Might Like... Ravinder Kapur Should I Rank My Employees? Every business organization struggles to get the best out of its employees. To achieve this, they have to ensure that they retain their top performers and get their remaining workers to improve their productivity and effectiveness. One way that ... Read more Jeffrey Glen Advise vs. Advice ADVERTISEMENT Adam Colgate Want to Increase Your Credit Score Quickly? Here ... Ravinder Kapur What are the Common Mistakes of New Managers? Email Print Embed Copy & paste this HTML in your website to link to this page contrast error Browse Dictionary by Letter: # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Never miss another term. Sign up for our FREE newsletter today! © 2016 WebFinance Inc. All Rights Reserved.Unauthorized duplication, in whole or in part, is strictly prohibited. Privacy, Disclaimers & Copyright COMPANY About Us Contact Us Advertise with Us Careers RESOURCES Articles Flashcards Citations All Topics FOLLOW US OUR APPS