... Paired Samples t-test 4. Independent Samples t-test 5. ANOVA 6. Chi Square Note that the version of SPSS used for this handout was 13.0 (Basic). Therefore, if you have advanced add-ons, or a more recent version there may be some slight differences, but the bulk should be the same. One possible difference would be for later versions or advanced packages to give the option of things like effect size, etc. In addition, the data used for these printouts were based on data available in the text: Statistics for the Behavioral Sciences, 4th Edition (Jaccard & Becker, 2002). If you have trouble with data entry, or other items not addressed in this guide, please try using the SPSS help that comes with the program (when in SPSS, go under the “help” tab and click on “topics”; you may be surprised at how “user friendly” SPSS help really is). At the end of this document is a guide to assist you in picking the most appropriate statistical test for your data. Note: No test should be conducted without FIRST doing exploratory data analysis and confirming that the statistical analysis would yield valid results. Please do thorough exploratory data analysis, to check for outliers, missing data, coding errors, etc. Remember: Garbage in, garbage out! A note about statistical significance (what it means/does not mean). Most everyone appreciates a “refresher” on this topic. Statistical Significance: An observed effect that is large enough we do not think we got it...
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...read, conduct, and write research. The contents are an expansion and revision of my class materials, intended for use as a refresher or as a free introductory research methods course. Topics are organized into five main sections, with subsections (in parentheses): * Introduction (INTRO)–a brief overview of educational research methods (3) * Quantitative Methods (QUANT)–descriptive and inferential statistics (5) * Qualitative Methods (QUAL)–descriptive and thematic analysis (2) * Mixed Methods (MIXED)–integrated, synthesis, and multi-method approaches (1) * Research Writing (WRITING)–literature review and research report guides (5) Most subsection contains a non-technical description of the topic, a how-to interpret guide, a how-to set-up and analyze guide using free online calculators or Excel, and a wording results guide. All materials are available for general use, following the Creative Commons License. Introduction (INTRO)–a brief overview of educational research methods 1. What is Educational Research? (uploaded 7.17.09) 2. Writing Research Questions (uploaded 7.20.09) 3. Experimental Design (uploaded 7.20.09) ------------------------------------------------- Experimental Design The basic idea of experimental design involves formulating a question and hypothesis, testing the question, and analyzing data. Though the research designs available to educational researchers vary considerably, the experimental design provides a basic model for...
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...characteristics about data. Descriptive statistics tell us information about the distribution of our data, how varied the data are, and the shape of the data. Now we are also interested in information related to our data parameters. In other words, we want to know if we have relationships, associations, or differences within our data and whether statistical significance exists. Inferential statistics help us make these determinations and allow us to generalize the results to a larger population. We provide background about parametric and nonparametric statistics and then show basic inferential statistics that examine associations among variables and tests of differences between groups. Parametric and Nonparametric Statistics In the world of statistics, distinctions are made in the types of analyses that can be used by the evaluator based on distribution assumptions and the levels of measurement data. For example, parametric statistics are based on the assumption of normal distribution and randomized sampling that results in interval or ratio data. The statistical tests usually determine significance of difference or relationships. These parametric statistical tests commonly include t-tests, Pearson product-moment correlations, and analyses of variance. Nonparametric statistics are known as distribution-free tests because they are not based on the assumptions of the normal probability curve. Nonparametric statistics do not specify conditions about parameters of the population...
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...Content READING YOUR REPORT YOUR AMCAT SCORES MODULE FEEDBACK YOUR PERSONALITY YOUR INDUSTRY AND JOB FITMENT IMPROVE YOUR EMPLOYABILITY NEXT STEP Chapter I. READING YOUR REPORT You must be having a lot of questions about your skills, personality and employability. AMCAT Employability Report will not only help answer these questions, but will become your guide for deciding next steps on your career path. It will tell you what to study, what interviews to prepare for and how to prepare. Refer to the following tips to understand how to make this report a means to get closer to your dream job. Start by referring to the 'YOUR AMCAT SCORE SUMMARY' chapter of your report. This chapter has all the key highlights for you. You will get to know where you stand nationally in different AMCAT modules, a snapshot of your personality and your employability in different job profiles and sectors. The summary chapter is the key. You should understand everything in it to know where you stand in the job market. For each section in the summary chapter, we mention the chapter having additional information about the section. Wherever you are unable to understand or want more information, refer to the respective chapter. The chapter 'Your Profile and Industry Fitment' is very important. The following tips will help you use it to make an action plan for next few months: a. For profiles where your employability is high, you should start refreshing your knowledge for an interview for them. You...
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...3 1. Planning phase 3 1. The aim of the measure 3 2. Defining the content of measure 4 3. The test plan 4 2. Item writing 5 1. Writing the items 5 2. Reviewing the items 5 3. Assembling and pre-testing the experimental version of the measure 6 1. Arranging the items 6 2. Finalizing the length 6 3. Answer protocols 6 4. Developing administration instructions 6 5. Pre-testing the experimental version of the measure 6 4. Item analysis phase 7 1. Item difficulty (p) 7 2. Discrimination power 7 3. Preliminary investigation into item bias 8 5. Revising and standardizing the final version of the measure 8 6. Technical evaluation and establishing norms 8 1. Issues related to the reliability of a psychological measure 8 1. Definition 8 2. Measurement error 8 3. The reliability coefficient 9 4. Standard error of measurement 9 5. Types of reliability 10 2.6.1.5.1. Reliability measures of stability 10 - Test-retest reliability - Alternate-form reliability 2.6.1.5.2. Reliability measures of internal consistency 11 - Split-half reliability ...
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...Chapter 10: Comparing Two Groups Bivariate Analysis: Methods for comparing two groups are special cases of bivariate statistical methods – Two variables exist: Response variable – outcome variable on which comparisons are made Explanatory variable – binary variable that specifies the groups Statistical methods analyze how the outcome on the response variable depends on or is explained by the value of the explanatory variable Independent Samples: Most comparisons of groups use independent samples from the groups, The observations in one sample are independent of those in the other sample Example: Randomized experiments that randomly allocate subjects to two treatments Example: An observational study that separates subjects into groups according to their value for an explanatory variable Dependent samples: Dependent samples result when the data are matched pairs – each subject in one sample is matched with a subject in the other sample Example: set of married couples, the men being in one sample and the women in the other. Example: Each subject is observed at two times, so the two samples have the same subject Categorical response variable: For a categorical response variable - Inferences compare groups in terms of their population proportions in a particular category - We can compare the groups by the difference in their population proportions: (p1 – p2) Example: Experiment: Subjects were 22,071 male physicians Every other day for five years, study participants...
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...Item Analysis Item Analysis allows us to observe the characteristics of a particular question (item) and can be used to ensure that questions are of an appropriate standard and select items for test inclusion. Introduction Item Analysis describes the statistical analyses which allow measurement of the effectiveness of individual test items. An understanding of the factors which govern effectiveness (and a means of measuring them) can enable us to create more effective test questions and also regulate and standardise existing tests. There are three main types of Item Analysis: Item Response Theory, Rasch Measurement and Classical Test Theory. Although Classical Test Theory and Rasch Measurement will be discussed, this document will concentrate primarily on Item Response Theory. The Models Classical Test Theory Classical Test Theory (traditionally the main method used in the United Kingdom) utilises two main statistics - Facility and Discrimination. * Facility is essentially a measure of the difficulty of an item, arrived at by dividing the mean mark obtained by a sample of candidates and the maximum mark available. As a whole, a test should aim to have an overall facility of around 0.5, however it is acceptable for individual items to have higher or lower facility (ranging from 0.2 to 0.8). * Discrimination measures how performance on one item correlates to performance in the test as a whole. There should always be some correlation between item and test performance...
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...1. The ages of employees at a small software development company, Crackerjack Networks, are listed below. What is the mean age of Crackerjack employees? Crackerjack Network Employees Source ------------------------------------------------- Top of Form * 24 * 25 * 25.25 * 2. The ages of employees at a small software development company, Crackerjack Networks, are listed below. In the event that Natasha Kramerbauer leaves the company to enter an MBA program, what is the median age of the remaining seven employees? Crackerjack Network Employees Source ------------------------------------------------- Top of Form * 24 * 25 * 25.25 * 24.5 3.The histogram below graphically represents the distribution of the number of passengers embarking from the 135 busiest airports in the United States in 1990. This distribution is: Source Uniform. Symmetric. Bimodal. 4. The histogram below graphically represents the distribution of the number of passengers embarking at the 135 busiest airports in the United States in 1990. Which of the following statements can be inferred from this histogram? Source The mean number of passengers embarking per airport is greater than the median number of passengers embarking per airport. The median number of passengers embarking per airport is greater than the mean number of passengers embarking per airport. The mean and median numbers of passengers embarking...
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...alternative hypothesis for a test of significance. Problem 2) At one school, the average amount of time that tenth-graders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased. Formulate the null and alternative hypotheses for the study described. Problem 3) A two-tailed test is conducted at the 5% significance level. What is the P-value required to reject the null hypothesis? Problem 4) A two-tailed test is conducted at the 5% significance level. What is the right tail percentile required to reject the null hypothesis? Problem 5) What is the difference between an Type I and a Type II error? Provide an example of both. Chapter 10 Show all work Problem 1) Steven collected data from 20 college students on their emotional responses to classical music. Students listened to two 30-second segments from “The Collection from the Best of Classical Music.” After listening to a segment, the students rated it on a scale from 1 to 10, with 1 indicating that it “made them very sad” to 10 indicating that it “made them very happy.” Steve computes the total scores from each student and created a variable called “hapsad.” Steve then conducts a one-sample t-test on the data, knowing that...
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...method, we test some hypothesis by determining the likelihood that a sample statistic could have been selected, if the hypothesis regarding the population parameter were true. Hypothesis testing or significance testing is a method for testing a claim or hypothesis about a parameter in a population, using data measured in a sample. In this method, we test some hypothesis by determining the likelihood that a sample statistic could have been selected, if the hypothesis regarding the population parameter were true. The method of hypothesis testing can be summarized in four steps. 1. To begin, we identify a hypothesis or claim that we feel should be tested. For example, we might want to test the claim that the mean number of hours that children in the United States watch TV is 3 hours. 2. We select a criterion upon which we decide that the claim being tested is true or not. For example, the claim is that children watch 3 hours of TV per week. Most samples we select should have a mean close to or equal to 3 hours if the claim we are testing is true. So at what point do we decide that the discrepancy between the sample mean and 3 is so big that the claim we are testing is likely not true? We answer this question in this step of hypothesis testing. 3. Select a random sample from the population and measure the sample mean. For example, we could select 20 children and measure the mean time (in hours) that they watch TV per week. 4. Compare what we observe...
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...alternative hypothesis for a test of significance. Problem 2) At one school, the average amount of time that tenth-graders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased. Formulate the null and alternative hypotheses for the study described. Problem 3) A two-tailed test is conducted at the 5% significance level. What is the P-value required to reject the null hypothesis? Problem 4) A two-tailed test is conducted at the 5% significance level. What is the right tail percentile required to reject the null hypothesis? Problem 5) What is the difference between an Type I and a Type II error? Provide an example of both. Chapter 10 Show all work Problem 1) Steven collected data from 20 college students on their emotional responses to classical music. Students listened to two 30-second segments from “The Collection from the Best of Classical Music.” After listening to a segment, the students rated it on a scale from 1 to 10, with 1 indicating that it “made them very sad” to 10 indicating that it “made them very happy.” Steve computes the total scores from each student and created a variable called “hapsad.” Steve then conducts a one-sample t-test on the data, knowing that...
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...When looking at two different reviews of the same game, how do audiences know which review to read? What makes one review better than the other? On the surface, both reviews provide ample information about the plot and gameplay. To fully analyze and compare the two reviews, we must look deeper into the structure of each, and from there we can decide which is a better review. After looking at various aspects of each review—paying attention to sentence style, readability score, and literary devices—we will be able to see differences between the two reviews. In this essay, we will look at two reviews of the video game “The Walking Dead: The Video Game” by The Telltale Series. Each is an online review written for game review websites; one of them was published by IGN Entertainment and written by Greg Miller, and the other published by GamesRadar+ and written by...
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...inferential statistics. This is a set of methods used to make a generalization, estimate, prediction or decision. Ex. Of 350 randomly selected people in the town of Luserna, Italy, 280 people had the last name Nicolussi. An example of inferential statistics is the following statement : "80% of all people living in Italy have the last name Nicolussi." We have no information about all people living in Italy, just about the 350 living in Luserna. We have taken that information and generalized it to talk about all people living in Italy. The easiest way to tell that this statement is not descriptive is by trying to verify it based upon the information provided. Ex. On the last 3 Sundays, Henry D. Carsalesman sold 2, 1, and 0 new cars respectively. An example of inferential statistics are the following statements : "Henry never sells more than 2 cars on a Sunday." Although this statement is true for the last 3 Sundays, we do not know that this is true for all Sundays. "Henry is selling fewer cars lately because people have caught on to his dirty tricks."...
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...Data Analysis in SPSS Jamie DeCoster Department of Psychology University of Alabama 348 Gordon Palmer Hall Box 870348 Tuscaloosa, AL 35487-0348 February 21, 2004 If you wish to cite the contents of this document, the APA reference for them would be DeCoster, J. (2004). Data Analysis in SPSS. Retrieved from http://www.stat-help.com/notes.html Heather Claypool Department of Psychology Miami University of Ohio 136 Benton Hall Oxford, OH 45056 All rights to this document are reserved Table of Contents Introduction ...................................................................................................................................................................1 Interactive Mode versus Syntax Mode ..........................................................................................................................2 Descriptive Statistics .....................................................................................................................................................4 Transformations.............................................................................................................................................................5 Compute ....................................................................................................................................................................5 Recode ............................................................................................................................
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...To begin with, the most crucial unit and basic important part of any assessment or a test is item. Brown, D. (2012) defines item as “the smallest unit that produces distinctive and meaningful information or feedback on a test when it is scored or rated”. (p. 41) Items format analysis defined as “the degree to which each item is properly written so that it measures all and only the desired content” (Brown, D. 2012, p. 42). Item analysis is a very useful and special to examine each particular item in a test or assessment and helps the instructors to create and make the item better. In addition, instructors can use item analysis as guidance and make the test items evaluate and revise in a persuasive way. The aims of using...
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