Dear HCP experts, We're currently analyzing some of the behavioral data from your dataset and have three short questions about the IRT-modelling and theta-score derivation that is also mentioned in the "NIH Toolbox Scoring and Interpretation Guide". To be able to build comparable scores between NIH-task data and Penn- and Working Memory data we would like to know more about the NIH IRT-scores. We hope you can help us out.
In the "NIH Toolbox Scoring and Interpretation Guide" it is mentioned that IRT-scores were calculated before the consecutive scores, such as Age-adjusted or Unadjusted. Was that also true for the HCP data? What was the database to estimate the IRT model for the HCP data? Was the model estimated based on the HCP data only or was it somehow combined with the norming sample of the NIH Toolbox? What type of IRT model was run? A simple Rasch model or did you add other free parameters, such as guessing probability (2PL)? Thank you very much for your help. Kind regards, Xinyang _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
