Pedro, I forget how many chances you get in corsi by default, but assuming it is 2, what I think the traditional span score does is gives a number for the level at which at least one set is recalled correctly. You are suggesting a criterion for which both are recalled correctly. Both of these are poor and biased estimates of the 50% point on the memory function. An unbiased estimate is the LD50 in logistic regression which is my favorite way of measuring a span score, and I think the method we use is also an unbiased estimate of this (but I don't have a mathematical proof and I haven't thought about this hard since I was working on my dissertation). 5.5 would indicate _either_ perfect recall at length 5, 1/2 at length 6; and 0/2 at 7; or it could indicate something like 2/2 at 4, 1/2 a 5, 1/2 at 6, and 1/2 at 7; 0/2 at 8. There may be some other ways to get that value as well.
You are free to score it however you want. The raw data is available for each subject, and the report you got this from is just a simple way to quickly get a number that is consistent across all users of PEBL. Best, Shane On Mon, 2016-11-07 at 16:01 +0000, Pedro Rodrigues wrote: > > Hello, > > I’m conducting my PhD thesis and for this end I’m using the Corsi > Block Test of the PEBL. > However, I have a doubt about the results which the program give me. > > Can you clarify me, please? > For instance, a participant had the following results: > > Last Item attempt to Complete: 6 > Total Score: 54 > Total Tentativas Correctas: 9 > Memory Span: 5.5 > > We can define “memory span” as span extension was established > as the length of the last list recalled correctly (two attempts for > each span length starting from 3 to a maximum of 9). > If this participant failed one of the two attempts of the item with 6 > blocks, why was not memory span 5? > In my interpretation, memory span is always an entire number or is my > impression wrong? > > > I look forward to hearing from you. > > Best regards, > _________________________________ > Pedro F. S. Rodrigues | PhD Student > Psychologist nº: 15329 (OPP) > University of Aveiro > Depart. of Education and Psychology (C.1.51) > Campus Universitário de Santiago > 3810-193 Aveiro | Portugal > Phone: (351) 234247144 ext. 24243 > Email: pedro.fil...@ua.pt > > ------------------------------------------------------------------- > ----------- > Developer Access Program for Intel Xeon Phi Processors > Access to Intel Xeon Phi processor-based developer platforms. > With one year of Intel Parallel Studio XE. > Training and support from Colfax. > Order your platform today. http://sdm.link/xeonphi > _______________________________________________ > Pebl-list mailing list > Pebl-list@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pebl-list ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Pebl-list mailing list Pebl-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pebl-list