Publications by George
Adaptive CDI Pruned 2PL
Introduction Our primary goal here is to develop and test via simulation a bank of CDI items and IRT parameters that we can recommend to those wanting to develop and conduct CDI computerized adaptive tests (CATs). Our approach is as follows: We first fit basic IRT models (Rasch, 2PL, 3PL, 4PL) to the wordbank CDI English Words & Sentences form da...
10481 sym 7 img 15 tbl
CDI-CAT: English Comprehension
Introduction Our goal here is to develop and test via simulation a bank of CDI:WG items and IRT parameters that we can recommend to those wanting to develop and conduct computerized adaptive tests (CATs) of children’s early word learning. This is to complement the CDI:WS item bank and parameters, and to be used by parents of children who are no...
7910 sym R (102 sym/1 pcs) 7 img 10 tbl
CDI-CAT: Spanish Comprehension
Introduction Our goal here is to develop and test via simulation a bank of CDI:WG items and IRT parameters that we can recommend to those wanting to develop and conduct computerized adaptive tests (CATs) of children’s early word learning. This is to complement the CDI:WS item bank and parameters, and to be used by parents of children who are no...
7480 sym R (102 sym/1 pcs) 7 img 10 tbl
Testing Diagnostic Validity of CDI-CAT
Goal From Philip Dale: “One highly attractive function of a CAT vocabulary measure would be for screening purposes. Evaluating its utility for that means looking at conventional measures of diagnostic validity such as sensitivity, specificity, PPV, and NPV, which are focused on the low end, rather than the broad range of scores. I’m wondering...
1248 sym R (5202 sym/7 pcs)
Standard Model - uniform priors
Loaded data for 680 CDI:WS items and 5492 subjects. Children’s word production as a function of age. Baseline vs. Frequency Model Our baseline model estimates a difficulty for each word and a rate (words per hour) for each child, and assumes that each child receives 12 (waking) hours per day of input. Although this model does not include word...
4555 sym 7 img
SmithYu2008
Test Smith & Yu (2008) / Yu & Smith (2011) After a couple minutes of “hand-tuning” I managed to find parameter values that closely match the overall 2AFC performance reported in Smith & Yu (2008), and a slightly different set that produce the higher performance in Yu & Smith (2011). # Smith & Yu 2008 / Yu & Smith, 2011 sy = read.table("SmithY...
1585 sym R (2446 sym/22 pcs) 1 img
XSL Model Bake-off
Introduction The goal of this study is to test the ability of a variety of cross-situational word learning models to account for a wide range of experimental data. Many models for cross-situational word learning have been proposed, and yet most of these models have only been tested on a few different experiments–often distinct ones, and only wi...
9082 sym R (1129 sym/5 pcs) 4 img
Standard Model Prior Predictive Check
Using a per-subject empirical hourly rate prior \(\sim Normal(1198, 200)\) and the somewhat arbitrary word difficulty \(\sim Normal(1000,500)\), along with an accumulation startage \(\sim Uniform(0,12)\) (the same for all subjects), we will sample production scores for 10 words for 10 subjects for both the baseline model (uniform probability of e...
2230 sym 2 img
ManyBabies 3 Power Analysis
Design For this power analysis we will simulate 20 labs contributing 20 infants (400 participants) from 5 to 12 months of age. Factors: familiarized_rule: indicates the sequence to which infants were exposed during familiarization (ABA or ABB). Infants were exposed to only one sequence, with the sequence determined by random assignment. (GK: not...
3857 sym R (5687 sym/8 pcs) 1 img
DLL Word List Evaluation
Goals The goals are 1) to create a word list that is informative about both English and Spanish vocabulary size and 2) to ensure that there are sufficient doublets to estimate lexical overlap. On an IRT view, we can’t perfectly assess 2 (at least not without better bilingual CDI data), but we can assess criterion 1 - that is, we can look at whe...
15267 sym R (6696 sym/17 pcs) 7 img