Homeogeneity Of Variance Test Minitab Express Manual Is Up
You may wish to sit down in front of a computer with Minitab running and work your way through the book, plugging examples into the computer as you go. What Is Bartlett’s Test of Homogeneity of VariancesHow you use this manual is up to you. This page provides links to this sample dataset and a guide to producing Bartlett’s test of Homogeneity of Variances using statistical software. In the some of the books to be found in the TBA travelling library and you will need to refer to this before analysing data.Specifically, we test the extent to which the variance of a married individual’s rating of own personal physical attractiveness differs by sex. This information is provided elsewhere e.g.
Having equal variances (like in case 3 of hypothesis tests for mean.For any queries concerning this document please contact: Tropical Biology AssociationDepartment of ZoologyDowning Street, Cambridge CB2 3EJ United Kingdom Tel: +44 (0) 1223 336619 e-mail: Biology Association 2008AcknowledgementThis booklet was adapted for use on the TBA courses with the kind permission of Dr Su Engstrand, University of Highlands & Islands.GETTING STARTED 51.1 NOTATION IN THIS MANUAL 51.2 MINITABS WINDOWS 51.3 ENTERING DATA 51.4 SAVING YOUR WORK 61.5 MANIPULATING DATA 71.5.1 Copying and pasting data 71.5.2 Manipulating data 71.5.3 Stacking and un-stacking data 8SUMMARISING DATA 102.1 GRAPHING DATA 102.1.1. Identify a test statistic T, that can be used to assess the truth of the null. In either case, we hope you fi nd this guide takes some of the fear out of statistics: computer analysis is a tool like any other, and will take a lot of the hard work out of statistics once you feel you are in charge!2.
Hopefully, you will all be familiar with using computer menus by now (from packages such as Word or Excel). Th is is much simpler than typing in commands (as we used to do in days gone by). Contingency table 253.3.5.2 Goodness-of-fi t test 251.1 NOTATION IN THIS MANUALAlmost all of the tests you will require Minitab to perform can be accessed from the menu which should appear across the top of the screen as soon as you open Minitab. Mann-Whitney test 233.3.2 Wilcoxon signed rank test 233.3.3 Kruskal-Wallis test 243.3.4 Spearman rank correlation 253.3.5 Chi-square test 253.3.5.1.
You can arrange your screen to show both windows simultaneously, or to show either window across the full screen. Th is would lead you to a screen as shown in Figure 1 on the next page.1.2 MINITABS WINDOWSWhen you open up a Minitab fi le, you are presented with two windows: the Worksheet window, where you will enter and store your data, and the Session window, which shows the results of your manipulationsAnd analysis (Figure 1). For example, the instructions to display descriptive statistics would be written as follows: Stat>Basic Statistics> Display Descriptive Statistics. Choosing a command will often lead to a second choice from a subsequent menu and this second choice will be shown after the symbol >.
It is a good idea to make these as specifi c as possible, so that you can remember exactly what data you want to choose for your analysis. Use the mouse to position the cursor immediately below the labels C1, C2 etc., then click and enter the variable name. Th e most common way to enter data is to put the names of each variable you have measured at the top of each column. Across the top, and row numbers shown down the side. You will also fi nd windows for any graphs produced appearing in this list.1.3 ENTERING DATAMinitab presents you with a blank worksheet, with columns, labelled C1, C2etc. Alternatively, choose the Session or Data window from the list given under Windows in the top menu bar.
Th is manual is written to correspond to version13, dont worry that we are using an older version and there are slight diff erences in how your screen looks. DONT PANIC! Just bear this in mind, try not to be put off and you should fi nd yourself equipped with a powerful tool to help you interpret your data.You will fi nd Minitab installed on all the TBA computers. However, it can seem a bit user un-friendly to start with. It is very powerful and, for the type of project you undertake on a TBA course, you are unlikely to need to do any analysis that Minitab cannot cope with.
Most participants choose to enter their data set in Excel and you can cut and paste directly from that programme into Minitab however, beware of problems of text vs. Th is manual will give instructions as to how the data should best be entered in Minitab for each test you are to perform, so read the appropriate section before you start typing in your data. When entering data directly, you should fi rst think hard about how you wish the data to be arranged.
Note that the fi rst variable (site) is labelled by Minitab as C1-T. Th e data for each of 7 variables (site to mass) are listed for each bird, so that you can read off the values for any one individual by reading left to right across the spreadsheet. Use the mouse or the cursor keys ( ) to move around the screen.Figure 2 shows data for biometrics measured on ten swallows.
You should get very used to this procedure. Click on Save on the right hand side of the window. You should normally choose to save the fi le to a folder you create on the desktop of your laptop.Name your fi le in the File name box try to use a sensible naming procedure which might include the topic, date, or fi le contents. You will be asked to give details of where you want to save the worksheet and what you want to call it. Saving a project saves all open worksheets, graphs and the session window together in a single fi le.
But if, you wanted to enter numeric data, but you typed a letter into a cell by mistake, even if you then erase it, Minitab may act as though you have entered text. In Figure 2, the site names are text. Letters instead of numbers).
Press enter.When you are saving for the second or subsequent time, File>Save Project will automatically save the fi le under the name you gave originally, by replacing the old version, so you dont need to type in the fi le name again. (If your data are in c2, obviously change what you type accordingly). Type aton c1 c1 if you wish to replace text data in c1 with numeric data in c1. Choose Editor>Enable Commands and the fl ashing cursor should appear after the Minitab prompt MTB>. So if you fi nd a T in any column heading, when the data are really numeric, you must get rid of the problem by converting text to numeric data: fi rst click anywhere in the session window to make it active.
If you have created important graphs, it makes sense to save them separately in a fi le of their own.
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