Hi,

I have downloaded ADHD data set, and I am planning to use it in my research
course, but I have many questions. Could you please help me to have better
understanding? Here are my questions :( some of these questions may look silly,
but it’s very important for me to understand everything to describe this data
to my professor)

1. For the age... 13.58 means 13 years and 58 days?

2. -999 mean missing value?

3. What is the meaning of the values for the variable Handedness that
belong to NYU? Handedness has only three values 0 Left, 1 Right, and 2Ambidextrous.
But their values contain different numbers like 0.67?

4.  How the variable “DX” was
measured? Is it based on medical examination “fMRI”?

5. What is Full IQ? and which IQ score we use ?

6. What are QC_Rest and QC_Anatomical?

I appreciate your cooperation,

Thanks,

Maryam