Hi Greg,

We are eager to know your opionion of  the gap in the spread of the
Language_Task_Story_Acc.
Hope that is not a problem in the data.

Thanks,
Jingwei


On Thu, Sep 28, 2017 at 5:03 AM, Elam, Jennifer <[email protected]> wrote:

> Hi Nicole,
>
> The emotion measures you mention are all from NIH Toolbox (TB), and they
> did all the scoring calculations based on the entire TB national sample, so
> you may want to ask them about the effect you see through their helpdesk at
> [email protected].
>
>
> The Anger Physical Aggression, Loneliness, Instrumental Support, and
> Perceived Rejection surveys measures you mention are very short
> (5-8 item) fixed length surveys with 5-7 point scales for raw item answers
> ranging from 1= "never" or "extremely untrue of me" to 5= "extremely true
> of me" or "always".  According to the NIH Toolbox Scoring and
> Interpretation Manual that was current when we froze the HCP protocol
> (attached), they are all scored with Item Response theory (IRT), which does
> not assume items to be equally difficult and therefore does not
> assume answers to be of equal value. The use of IRT might have
> contributed to the irregular spread at one end of the scale.
>
>
> Furthermore, the questions on these surveys measure more
> extreme behavior/level of support (see pp. 226-277 of the attached TB Data
> Dictionary for the questions asked) and we did have a lot of our normal,
> healthy HCP young adult subjects answer these surveys in a way that put
> them on one end of the scale (e.g. answered all items "never", or
> "always"), which created an understandable floor or ceiling effect in the
> data for these assessments. Looking at the raw item level data, subjects
> with one item level answer 1 point away from the floor or ceiling jump to
> the next value in the spread.
>
>
> Greg, perhaps you can comment on the gap in the spread of the 
> Language_Task_Story_Acc?
> My only comment is that the Story part of the Language task is relatively
> easy, so a high number of subjects with 100% accuracy is expected.
>
>
> Best,
>
> Jenn
>
>
> Jennifer Elam, Ph.D.
> Scientific Outreach, Human Connectome Project
> Washington University School of Medicine
> Department of Neuroscience, Box 8108
> 660 South Euclid Avenue
> St. Louis, MO 63110
> 314-362-9387
> [email protected]
> www.humanconnectome.org
>
> ------------------------------
> *From:* [email protected] <hcp-users-bounces@
> humanconnectome.org> on behalf of Nicole Kuek <[email protected]>
> *Sent:* Tuesday, September 26, 2017 1:06:12 AM
> *To:* [email protected]
> *Subject:* [HCP-Users] Data outliers
>
> Dear HCP experts,
>
> In looking through some of the emotion and cognition behavioural data in
> the hcp, we have noted some outliers that do not seem to be explained by a
> floor or a ceiling effect. For example, AngAggr_Unadj, where a large group
> of subjects have one much lower score, that is not continuous with the
> spread of the other values (see attached figure AngAggr_Unadj).
>
> We have found this in a few of the emotion measures, both above and below
> the spread (e.g Lonliness_Unadj, InstruSupp_Unadj, PercReject_Unadj, etc).
> Please advise.
>
> Furthermore, should we be concerned about the gap between subjects scoring
> 100 and 80+ in Language_Task_Story_Acc (see attached figure
> Language_Task_Story_Acc)?
>
> --
> Best Regards,
>
> Nicole K.
>
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