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Diverse opinions about cognitive process models

The survey Process Models in Judgment and Decision Making is an expert survey we conducted to find out about researchers’ opinion about the term “process model” and whether it applies to several models in the field. The main objective was to find out whether researchers’ agree or disagree about which models ought to be called “process model”. We contacted 118 authors of well-known decision-making models per email and decision scientists via mailing lists (SJDM, largest decision science list, www.sjdm.org; list […]

Inter-rater reliability for unequal raters per item: Fleiss-Cuzick’s kappa

Inter rater reliability If you want to obtain inter-rater reliability measures for dichotomous ratings, by more than two raters, but not all raters rated all items, Fleiss and Cuzick (1979) will be the referece you’ll find. For example, we asked researchers which model they consider a process model (dichotomous rating), and we asked about 60 researchers (more than two rater), of whom not everyone was familiar with every model (not all raters rated all items). They proposed a measure between […]

R does not round 2.5 to 3

In R’s default rounding function round() odd numbers ending with .5 are rounded up (from 1.5 to 2), but even numbers are rounded down (from 2.5 to 2 not to 3). This is compliant with a norm on rounding as outlined in the R documentation. I need to round 2.5 to 3 nevertheless in order to break an otherwise infinite loop in my iterative parameter approximation. Here is a solution I found on Stock Overflow who had it from statistically […]

Save parameters and seeds of simulations

Today, Robert posted the nice idea to save seeds of simulations. He recommends storing seeds with results, alternatively, store seeds with starting parameter values if you run numerical optimization. It is also useful to create an external file which stores parameters and seeds with a unique identifier which one can use for naming results folders and file organization. Th is post contains a code to do the latter.

RGL Package for animated graphs

I recently discovered the RGL package for R to create animated graphs. I used it for 3D-surface plots for likelihood functions – I’ll post about this soon. The R mailing list posted this fun animation of cubes by Francis Smart using the very samen package.