What type of sampling is described in this study?
A company that sells hair-care products wants to
determine if a product that combines shampoo and
conditioner works better than a shampoo and
conditioner used separately. A researcher recruits 60
volunteers and pairs them according to age, hair color,
and hair type. For each pair, the researcher flips a coin
to determine which volunteers will use the
shampoo/conditioner combination and which ones will
use the separate shampoo and conditioner. After using
the products for one month, the subjects are asked to
rate their satisfaction with the hair products on a scale
of 1-10 (1 = highly dissatisfied and 10 = highly
satisfied). What type of sampling is described in this study?
one sample
paired data
two samples
more than two samples
