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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Dear Mark,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">By the way, this type of question is more appropriate for the list<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><a href="http://groups.yahoo.com/groups/stocnet/">http://groups.yahoo.com/groups/stocnet/</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">than for this one – this one focuses on coding issues.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Predicting binary outcomes is very difficult in general, and I am not a fan of judging statistical models on their ability in this respect.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">For network models the situation is even more complicated, because here the dependence between tie variables is an essential part of the model, and not captured
by counting correct predictions. For example, a network model will predict that there are a lot of closed triads, but a longitudinal network model will not predict where they are (unless some open triads are available already).
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">This is the reason why sienaGOF() focuses on occurrence of patterns (e.g., goodness of fit of the triad census) rather than individual tie predictions.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Best wishes,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Tom<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">================================================================<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Tom A.B. Snijders<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Professor of Statistics in the Social Sciences<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Department of Politics and Department of Statistics<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Nuffield College<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">University of Oxford<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">tel. +44-01865-278599<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> rsiena-help-bounces@lists.r-forge.r-project.org [mailto:rsiena-help-bounces@lists.r-forge.r-project.org]
<b>On Behalf Of </b>Mark Manger<br>
<b>Sent:</b> 02 July 2014 22:06<br>
<b>To:</b> rsiena-help@lists.r-forge.r-project.org<br>
<b>Subject:</b> [Rsiena-help] checking for correctly predicted network evolution<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Dear fellow RSiena users, <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I tend to apply RSiena to problems that in Political Science are usually treated with binary dependent variable models, most commonly logit models.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">With logit models, because it is relatively simple, people often calculate a “percentage correctly predicted” of outcomes, and then perhaps list which specific outcomes were over- or underpredicted. This is generally (perhaps wrongly) considered
as a good check of the explanatory power of a model, and frequently requested by reviewers.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I’m wondering if it would be possible to do the same in RSiena — predict (or rather simulate the networks given my estimated parameters), compare with the actually observed networks, and calculate a percentage correctly predicted in each
wave?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">—Mark<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span lang="EN-CA" style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#002F65">Mark S. Manger</span></b><span lang="EN-CA" style="font-size:7.5pt;font-family:"Arial","sans-serif";color:black"> <br>
Assistant Professor of Political Economy and Global Affairs</span><span style="font-family:"Helvetica","sans-serif";color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-CA" style="font-size:7.5pt;font-family:"Arial","sans-serif";color:black">Munk School of Global Affairs & Department of Political Science | University of Toronto<br>
Observatory Site | 315 Bloor Street West | Room 212<br>
Toronto, ON M5S 0A7<br>
Phone: 416-946-8927 | Fax: 416-946-8877</span><span style="font-family:"Helvetica","sans-serif";color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="font-size:7.5pt;font-family:"Arial","sans-serif";color:black"><a href="mailto:mark.manger@utoronto.ca">mark.manger@utoronto.ca</a><br>
</span><b><span lang="EN-CA" style="font-size:7.5pt;font-family:"Arial","sans-serif";color:#17365D"><a href="http://www.munkschool.utoronto.ca/mga">www.munkschool.utoronto.ca/mga</a></span></b><span lang="EN-CA" style="font-size:7.5pt;font-family:"Arial","sans-serif";color:black"><br>
<br>
</span><span lang="EN-CA" style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:#B42C33">JOIN THE GLOBAL CONVERSATION</span><o:p></o:p></p>
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