Overall / No Print / Onscreen Print / F/χ2 / L-SES / WC-SES / F/χ2
Sample Size (n) / 121 / 60 / 61 / 49 / 72
Gender (n) / 54 boys
67 girls / 28 boys
32 girls / 26 boys
35 girls / 0.20 / 16 boys
33 girls / 38 boys
34 girls / 4.78*
Birth Order (Mean) / 1.93
(SD = 0.86) / 1.89
(SD = 0.88) / 1.98
(SD = 0.85) / 0.42 / 2.29
(SD = 0.91) / 1.69
(SD = 0.73) / 16.15***
Age (Mean) / 5.74 years
(SD = 1.20) / 5.80 years
(SD = 1.22) / 5.68 years
(SD = 1.18) / 0.32 / 5.70 years
(SD = 1.26) / 5.77 years
(SD = 1.16) / 0.09
Identified Disability / 8 / 5 / 3 / 0.45
Family Size / 4.26
(SD = 1.15) / 4.32
(SD = 1.26) / 4.21
(SD = 1.02) / 0.30 / 4.83
(SD = 1.12) / 3.88
(SD = 1.00) / 23.93***
Mom’s Education (Mean) / 13.88 years
(SD = 2.65) / 13.95 years
(SD = 2.64) / 13.82 years
(SD = 2.68) / 0.07 / 12.35 years
(SD = 2.21) / 14.93 years
(SD = 2.42) / 35.63***
Family Income (Mean) / $37,968
(SD = 23,885) / $35,267
(SD = 23,396) / $40,625
(SD = 24,254) / 1.53 / $20,239
(SD = 9,143) / $50,033
(SD = 23,305) / 72.34***
Income-to-Needs (Mean) / 1.41
(SD = 1.05) / 1.27
(SD = 0.95) / 1.55
(SD = 1.12) / 2.23 / 0.64
(SD = 0.26) / 1.94
(SD = 1.05) / 71.92***
Language Spokena / 69.8% English
7.0% English/Other
23.3% Other / 69.8% English
7.0% English/Other
23.3% Other / 78.6% English
4.8% English/Other
16.7% Other / 0.86 / 87.1% English
0% English/Other
12.9% Other / 66.7% English
9.3% English/Other
24.1% Other / 5.21+
Family SES / 49 L-SES
72 WC-SES / 28 L-SES
32 WC-SES / 21 L-SES
40 WC-SES / 2.21
0.30
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Overall / No Print / Onscreen Print / F/χ2 / L-SES / WC-SES / F/χ2Pretest Vocabulary Scores
Receptive Vocabulary / 58.67
(SD = 10.58) / 58.84
(SD = 11.43) / 58.51
(SD = 9.75) / 0.03 / 55.98
(SD = 10.48) / 60.51
(SD = 10.31) / 5.56***
Expressive Vocabulary / 16.85
(SD = 10.53) / 16.14
(SD = 10.29) / 17.54
(SD = 10.80) / 0.53 / 13.83
(SD = 10.58) / 18.90
(SD = 10.06) / 7.12***
Standardized PPVT-4 / 95.10
(SD = 14.12) / 93.16
(SD = 15.87) / 97.00
(SD = 11.99) / 0.32 / 87.96
(SD = 12.01) / 102.63
(SD = 14.26) / 27.54***
Total Views (Mean) / 24.17
(SD = 23.79) / 23.07
(SD = 19.96) / 25.26
(SD = 27.17) / 0.26 / 22.39
(SD = 24.62) / 25.39
(SD = 23.31) / 0.46
***p < .001; **p < .01; *p < .05; +p < .10
aA variety of languages were spoken in the home including Spanish, African, and Asian languages.Asian languages included Cantonese, Chinese, Mandarin, Filipino-Bicol dialect, and Japanese. When analyzing by individual languages, some of the cells had an expected count less than 5; therefore, languages were collapsed into English only, English and another language, or another language.
Supplemental Table 2. Parent-Reported Frequency with which They Engaged in Literacy-Related Parent-Child InteractionsScale/Item / Total Sample / L-SES / WC-SES / F (p-value)
Oral Language Scale (⍺ = .80) / 3.95 (SD = 1.90) / 4.18 (SD = 1.93) / 3.81 (SD = 2.03) / 0.76 (p = .387)
I teach my child letters
I teach my child how to write letters
I teach my child how to say letter sounds
I play language games (like rhyming) during personal care routines (bathing, diapering, etc)
I sing or repeat rhymes to my child
My child and I play educational games or with literacy toys (e.g., Leap Frog)
Reading Style Scale (⍺ = .64) / 4.46 (SD = 1.77) / 4.11 (1.62) / 4.69 (1.84) / 3.28 (p = .073)
I or someone in my family reads aloud to my child at bedtime.
I change my voice or my tone to fit stories when I read aloud to my child.
Note. L = Low SES; WC = Working-Class SES. Both scales range from 0 = rarely or not at all to 8 = multiple times per day.
Supplemental Table 3. Parent-Reported Frequency with which They Engaged in TV-Related Parent-Child Interactions
Never (0) / Sometimes (1) / Often (2) / Always (3) / Mean (SD)
L / WC / L / WC / L / WC / L / WC / Χ2 (p-value)
TV Mediation (⍺ = .91) / 0% / 9.4% / 38.7% / 49.1% / 35.5% / 30.2% / 25.8% / 11.3% / 1.83 (SD = .67) / 6.02 (p = .111)
Point out why some things actors do are good
Point out why some things actors do are bad
Try to help my child understand what s/he sees on TV
Explain what something on TV really means
Explain the motives of TV characters
TV as Shared Activity (⍺ = .91 ) / 0% / 7.5% / 22.6% / 47.2% / 38.7% / 37.7% / 38.7% / 7.5% / 1.44 (SD = .77) / 15.42 (p = .001)
Watch together because we both like a program
Watch together because of a common interest in a program
Watch together just for fun
Watch your favorite program together
Laugh with child about the things you see on TV
Note. L = Low SES; WC = Working-Class SES
Supplemental Table 4. Target words selected to approximate the larger distribution of words found in all Martha Speaks episodes used in this study
Target Word / Type of Instruction / Word Level Quartile / Repetition Within Storyescape / Explicit / 1 / 2
mumble / Explicit / 2 / 1
disobedient / Explicit / 2 / 2
insult / Explicit / 2 / 2
elect / Explicit / 2 / 3
improve(ment) / Explicit / 2 / 3
(un)fortunate / Explicit / 2 / 3
guilty / Explicit / 2 / 3
overcome / Explicit / 3 / 2
influence / Explicit / 3 / 2
expression / Explicit / 3 / 2
deny / Explicit / 3 / 2
effort / Explicit / 3 / 2
opportunity / Explicit / 3 / 2
problem / Explicit / 3 / 2
rescue / Explicit / 3 / 2
unique / Explicit / 4 / 2
knack / Explicit / 4 / 2
bizarre / Explicit / 4 / 2
ecstatic / Explicit / 4 / 2
polite / Implicit / 1 / 1
bad / Implicit / 1 / 1
work / Implicit / 1 / 2
story / Implicit / 1 / 2
catch / Implicit / 1 / 3
grow(n)(th) / Implicit / 2 / 1
accident / Implicit / 2 / 2
communicate / Implicit / 2 / 2
false / Explicit / 1 / 2
concentrate / Explicit / 4 / 3
Note. Type of instruction is coded as explicit (i.e., words that were central to the story, were explicitly defined using both visual and verbal content simultaneously, and were repeated and expanded upon during the story) or implicit (i.e., words that were not explicitly taught or defined by characters and story action. These words were typically featured in program dialogue.). Word level quartile refers to the grade level of a particular word as defined by Dale and O’Rourke (1981) and is coded as 1 = grades 1/2, 2 = grades 3/4 , 3 = grades 5/6, 4 = grades 7/8. Repetition within story refers to how frequently a target word was repeated in the story and is coded as 1 = 1 to 3 times per episode, 2 = 4 to 7 times per episode, 3 = 8 or more times per episode.