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DataToText: A Consumer-Oriented Approach to Data Analysis David A. Kenny University of Connecticut http://davidakenny.net/doc/aps10.ppt http://davidakenny.net/doc/aps10.doc Data Analysis for Methodologists Begin with a hypothesis that is embedded within a statistical model. Develop a research and measurement design to estimate the parameters of that model. Gather data; test model assumptions; and estimate the model’s parameters. Choose the best model. Data Analysis for Practitioners What do I have to click in SPSS? What from my SPSS output do I put where in my results section? Consumer versus “Industry” Perspective For data analysis, quantitative psychologists are the “industry” or at least part of the industry. The spirit of DataToText is an attempt to get us to become more “consumeroriented.” DataToText Project Have the researcher tell DataToText what is the research question. DataToText performs the requisite analyses. DataToText gives the results from those analyses: computer output a written description Example 1 http://davidakenny.net/moderate.htm Moderation Analysis Livi et al.: The effect of Noise Sensitivity (X) on Stress (Y) is moderated by the Need for Cognitive Closure (M) Moderation Example Syntax Gives results in words, tables, and pictures Tests assumptions Gives warnings Specialized output Example 2 How Positively the Wife Sees the Husband How Positively the Wife Sees the Husband Actor Wife Wife Satisfaction Husband Satisfaction Actor Husband http://davidakenny.net/ddt/apimd.htm Syntax Picture Specialized Output Advantages and Disadvantages DataToText is Mindless! Thought and intelligence is needed for: What analysis to do The execution of the analysis The interpretation of the analysis High school student Jenna Smith randomly throwing variables into the macro. Researcher Brad Anderson not knowing anything about testing moderation. Definitely bad, probably terrible. However, it might be better than what would have otherwise been done. Additionally Sometimes warnings may alert the user that the wrong analysis was done. For example, both macros provide a warning if a dichotomous variable is analyzed. DataToText is Mindless! about: What analysis to do The execution of the analysis The interpretation of the analysis Data Analysis Requires Thought Not all problems have a flowchart structure CFA ARIMA modeling However Some problems have a flow-chart structure (though we might disagree some about that flowchart). For many analyses we do have explicit or implicit standards for reporting of results. Also Keeps everything straight. Avoids errors. DataToText while it may typically fail to perform the best analysis, it might often create a better analysis than that done by even a skilled data analyst. Provides warnings. Makes assumptions explicit and can provide statistical tests of some of them. Warnings DataToText issues warnings: A dichotomous outcome variable Outliers Colinearity Low Power Assumption Testing Is Like Flossing Something we know that we should do but do not do as often we should. DataToText can test certain assumptions level of measurement distributional outliers DataToText is Mindless! about: What analysis to do The execution of the analysis The interpretation of the analysis The Researcher Needs to Understand the Results Good data analysis is more than doing the right analysis; the researcher must still understand the meaning of the results. However Because DataToText provides a verbal summary of the results, some researchers might better understand their results by using the approach. Moreover Output produced by DataToText may be more intelligible to the reader and so although the data analyst may not understand the results, the reader may be able to! Packages vs. Open Source Packages PASW (née SPSS), SAS Accessible but costly Updates sometimes without backwards compatibility Open Source: R Feedback Please let me know what you think. [email protected] http://davidakenny.net/doc/aps10.ppt http://davidakenny.net/doc/aps10.doc Special Thanks to My Lab • Thomas Ledermann • Amanda Snook • Randi Garcia