Textbooks

The numerous online resources will get you so far, but for a comprehensive guide to how to do statistics using SPSS (or any other statistical software) and how to interpret the results, you will need a text book.  Field (2009) is essential reading, and Dancey and Reidy (2008) is a good alternative.   Both are available from the University Library.   For help on reporting your results, try Field and Hole(2003).

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Using Excel

Before encountering SPSS or any other statistical software, we generally have to organise our data in some form using Excel spreadsheets.  Try this  guide to the basics of using Excel  or this pdf document if you are using Excel for Survey Questionnaires.

If you want to go a step further a do some basic statistics in Excel, try this guide to using statistical functions in Excel using Excel 2003.  There are numerous resources out there using Excel Templates for common statistical tests.  For example, Pearson’s Correlation Coefficient or Pearson’s rChi-Squaret-tests, including the One-Sample t-test, the Independent Samples t-test, and the Dependent Samples t-test, and the ANOVA, or Analysis of Variance.  But bear in mind that some statistical tests on Excel are not as accurate as using stats software such as SPSS.   See  numerical methods in Excel for more details.

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Stats calculation tools

There are a number of online tools for calculating basic statistics.  This Psychology.org site provides a long list of websites and links of tips, tools and blogs.  Try this  Free online tool  Its modular design and sophisticated interface makes it very easy to use. It provides parametric (t-Test, 1 way ANOVA, correlation, linear Regression,..) and non-pararmetric tests (chi-square, Wilcoxon, Mann-Whitney, Friedman, Kruskal-Wallis,…), useful data handling functions and creates high resolution graphs…but you do need to register.  StatTools is a collection of statistical programs that were used in clinical research and quality assurance.  Lots of useful tools to explain and calculate many tests, both parametric and non-parametric from t-tests up to anova, regression and meta analyses, although some terminology may be different from what you are used to.

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Explaining Statistical Concepts

Lots of statistics sites cover the basic information so it makes sense to be clear on what exactly you are looking for. Do you need to look up something quickly or have you a bit of time to spend going through a site in some detail? Do you just want a simple explanation or are you going to do some revision that includes working through examples? It is probably best to put aside a bit of time to explore these sites so that you know where to go if you are short of time. Introductory level sites are generally suitable for levels 1 & 2, intermediate sites up to level 3 and advanced levels 3 & 4 and beyond. Sites suitable for all levels are generally comprehensive and include a variety of tests and materials.

For Level 1 and 2 psychology and revision of basic concepts try SUMS.  An interactive website, using real data from research and teaching.  Explains statistical concepts at 3 levels, up to t-test and correlations. Useful for basic concepts and revision for level 3 if you need it! Includes lots of opportunities to test yourself.  Needs time to work through the examples properly rather than instant solutions. For a brief outline of ANOVA (and other tests from the home page)  Goes through output from SPSS step by step for each test.  Site hasn’t been updated since 2000.

If you have time to browse, try an online stats textbook,  this one includes demos and simulations. Useful for understanding statistical concepts. Another  online stats textbook and resource is SOCR which is useful for explaining concepts, but may go beyond the scope of the analyses required by psychology UG projects.   Students  may find the SOCR class notes, analyses, computational and graphing tools extremely useful in their learning/practicing pursuits.  The WISE online tutorials in statistical concepts has many useful interactive exercises on choosing the correct statistical test.
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Statistics Blogs

For some statistics is a hateful evil and for others they are a necessary tool.  However there are a small band of individuals for whom statistics are a quiet passion (before you scoff at such people, consider how useful it would be to have one as a friend).  Some of these individual choose to spread the word through rather useful blogs.  A few of which are discussed below the fold.

Continue reading

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SPSS and “How to” guides on the web

SPSS (it now called PASW) is still the most popular statistics package in psychology and it is the one that is most used in honours year here at Glasgow.  In terms of on-line resources there are a lot out there of variable quality.  Continue reading

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Statistics: Andy Field’s site

One of the required books for level 3 Psychology is Andy Field’s “Discovering Statistics Using SPSS”.  The book is a veritable compendium of Statistical Wisdom.   Beyond this the Andy has a excellent site called Statistics Hell with a lot of extra resources to help you with understanding Statistics and using SPSS.  Continue reading

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Choosing Statistical Tests

There are lots of sites out there that help you to select which statistical test to use, some of which are below. You probably need to know a few basics before you start, such as what type of design you are using, what the independent and dependent variables are and the difference between types of measurement such as categorical and continuous variables.  It is often worth having a look at a couple of the sites to see the different types of information you get. Clearly it makes sense to decide on what type of data you are gathering and the statistics you want to use at a very early stage of your experimental design.

Which Test is a comprehensive guide intended for clinical psychologists to help select the appropriate statistical test, based on the experimental design. Very helpful when selecting a test, but does not give details of how to analyse the data.  Sponsored by the Higher Education Academy Psychology Network.  Easy to use. Take the time to use the help and examples functions if you need to.

Dancey and Reidy produced an interactive Decision Chart    to help you decide which test to use from Chapter on 1 way ANOVA on the companion website to Dancey and Reidy Statistics without Maths (4th Ed). This chart will ask a few questions about your design and then refer you to the relevant chapter of their textbook.  Click on the Interactive Decision Chart from the left hand menu. You need to have the textbook to follow up their chapters, however you can look up the relevant chapters in a different book if you don’t have this one.   For an overall view try the Wise online tutorials in statistical concepts. Useful interactive exercises on choosing the correct statistical test. Useful for basic concepts and revision for level 3 if you need it! Requires Java.

If you prefer a decision tree analysis so that you can see all the options at once, try Corston & Colman 2000 and Neill & Howell 2008.  Other static guides include Intuitive Biostatistics,  don’t let the title put you off…Lets you select a test based on your data and the goal of your research.  Uses a grid structure to pick a test based on the type of data you are looking at such as parametric or non-parametric. Includes a useful list of points to consider, but is limited to contents of the associated text book. The American Thoracic Society has produced a good review  compiling a “Best of the Web” on sites that aid in choosing the best statistical test for a given set of data, but you need a bit of time to sort through all the information.

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