Table 3

Item description and estimates of DIF where significant
Items Item questions CTT IRM
Mean (SD) CITC Difficulty differences
Low edu.-High edu.a English-Spanishb 3-5 yo -5-8 yoc 3-5 yo-9-12 yod 5-8 yo -9-12 yoe
Social Co-viewing (Cronbach’s alpha = 0.83)
1 How often do you watch TV together because you both like a program? 3.42 (0.67) 0.68
5 How often do you watch your favorite program together? 3.35 (0.74) 0.7 0.3* -0.41* -0.37*
6 How often do you laugh with your child about the things you see on TV? 3.67 (0.54) 0.62 0.35*
12 How often do you watch TV together because of a common interest in a program? 3.41 (0.67) 0.67 0.34*
14 How often do you watch TV together just for fun? 3.35 (0.67) 0.51
Instructive Mediation (Cronbach’s alpha = 0.83)
2 How often do you explain what something on TV really means? 3.47 (0.63) 0.54 0.67*** -0.6** 0.88*** 1.15***
4 How often do you try to help your child understand what she/he sees on TV? 3.53 (0.66) 0.58 -0.4*
8 How often do you point out why some things actors do are bad? 3.53 (0.74) 0.65 0.34* 0.5**
10 How often do you point out why some things actors do are good? 3.44 (0.74) 0.69
13 How often do you explain the motives of TV characters? 3.19 (0.77) 0.7
Restrictive (Cronbach’s alpha = 0.72)
3 How often do you specify in advance the programs that may be watched? 3.47 (0.76) 0.41 0.41* -0.36*
7 How often do you set specific viewing hours for your child? 3.16 (0.96) 0.49 -0.33* -0.24*
9 How often do you tell your child to turn off the TV when he/she is watching an unsuitable program? 3.65 (0.74) 0.42 0.25*
11 How often do you restrict the amount of TV your child can watch? 3.39 (0.78) 0.56 -0.46** -0.3*
15 How often do you forbid your child to watch certain programs? 3.51 (0.72) 0.54

Note.*small effect (difference < 0.426); **moderate effect (0.426 < difference < 0.638); ***large effect (difference > 0.638).

aPositive numbers, easier for high education; Negative value, easier for low education; bPositive numbers, easier for Spanish; Negative value, easier for English.

cPositive numbers, easier for 5–8 years old; Negative value, easier for 3–5 years old; dPositive numbers, easier for 9–12 years old; eNegative value, easier for 3–5 years old.

Chen et al.

Chen et al. International Journal of Behavioral Nutrition and Physical Activity 2013 10:41   doi:10.1186/1479-5868-10-41

Open Data