Identify the Design of Each Experiment Below as Paired Samples

Short Answer

Identify the design of each experiment below as paired samples or independent samples. In each case give the df.
-In order to control for socioeconomic status, this study only used families with incomes in the $25-$35,000 a year range. Thirty-six fathers of one-year-olds were compared. Half had participated in the Lamaze method a year earlier when their child was born and half had not. A non-verbal behavior score was taken during a 10-minute father-child session.