Apologies but this is a very basic, probably naive question from someone with little to no comprehension of statistical ideas.
I need to interpret some results that use statements about the SD as a measure. These are from a couple of statistical surveys on the effects on test scores of laptop use in classrooms
What does it mean to say:
"...student test scores improve by 6.41% of a standard deviation"
Sample size: 130,482
" [The results show that the use of laptops] ... reduces final exam scores by 18% of a standard deviation"
Sample: size 726
Any guidance appreciated. Thanks