get_balance_data = function(){
    ##
    ## xpdf ../EBook/Applied_Linear_Models_with_R.pdf -z 200 99 &
    ##
    lines = 'Subject_Number Forward_N_Backward Side_to_Side Age_Group
    1 19 14 elderly
    2 30 41 elderly
    3 20 18 elderly
    4 19 11 elderly
    5 29 16 elderly
    6 25 24 elderly
    7 21 18 elderly
    8 24 21 elderly
    9 50 37 elderly
    1 25 17 young
    2 21 10 young
    3 17 16 young
    4 15 22 young
    5 14 12 young
    6 14 14 young
    7 22 12 young
    8 17 18 young'
    con = textConnection (lines)
    DF = read.table(con, header=TRUE)
    close(con)

    DF
}