Z-scores of Students

Number of students who scored at least 1 SD below the mean

Variables Number of students between -1 & -2 SD Number of students 2 or more SD below
Rapid digit naming 39 29
Rapid letter naming 32 37
Word reading 47 10
Phonemic (nonword) reading 37 3
Elision 8 1
Memory for digits 3 1
Nonword repetitoin 2 0
Verbal comprehension 0 0
Concept formation 1 0

Number of students scored 1 or more SD above the mean

Number of student who scored above 1 SD in at least one of the word tests (Sightword, nonword/phonemic decoding) = 0

Number of student who scored above 1 SD in at least one of the RAN tests (RAN digit, RAN letter) = 1

Below are the histograms of the z-scores for each variables

One-Sample t-tests (Comparing sample with population mean) -One-Tailed

To determine if the mean of a single sample is significantly less than a known population mean

N=73

Variables Mean SD t df p-value Mean Difference 95% CI mean difference (upper)
Rapid digit naming 4.959 2.89 -14.934 72 2.2e-16 -5.041096 5.521365
Rapid letter naming 4.479 2.76 -17.094 72 2.2e-16 -5.520548 5.017599
Word reading 79.42 9.48 -18.542 72 2.2e-16 -20.57534 81.27366
Phonemic (nonword) reading 83.71 10.14 -13.719 72 2.2e-16 -16.28767 85.69068
Elision 9.42 1.74 -2.8261 72 0.003047 -0.575342 9.763883
Memory for digits 10.97 2.76 3.0068 72 0.9982 0.9726 11.5116
Nonword repetitoin 10.67 2.43 2.363 72 0.9896 0.67123 11.14456
Verbal comprehension 103.7808 8.87 3.6432 72 0.9997 3.7808 105.51
Concept formation 108.5205 10.87 6.6954 72 1 8.5205 110.6411

Scatter Plot Matrix for the 9 Variables

To visualize relationships between multiple variables

View the plot full screen click here (open in new tab or copy link and paste in browser->download file -> open file)

Significant Correlations

  • Rapid digit naming ~ Sighword reading: r= 0.4390045, p = 0.0001022
  • Rapid digit naming ~ Rapid letter naming: r= 0.9117783, p < 2.2e-16
  • Rapid digit naming ~ Memory for digits: r= 0.3971457, p = 0.0005035
  • Rapid digit naming ~ Nonword repetition: r= 0.5814069, p = 6.902e-08
  • Rapid letter naming ~ Sighword reading: r= 0.4088624 , p = 0.000329
  • Rapid letter naming ~ Memory for digits: r= 0.4260914, p = 0.0001709
  • Rapid letter naming ~ Nonword repetition: r= 0.5775901, p = 8.797e-08
  • Sighword reading ~ Phonemic decoding: r= 0.5099121, p = 4.067e-06
  • Phonemic decoding ~ Nonword repetition: r= 0.3007376, p = 0.009729
  • Elision ~ Nonword repetition: r= 0.2506713, p = 0.03243
  • Memory for digits ~ Nonword repetition: r= 0.5763426, p = 9.516e-08
  • Verbal comprehension ~ Concept formation: r= 0.5170883, p = 2.814e-06

While anlayzing the scatter plot matrix, I identified a potential outlier

Scores of the Outlier Participant
ParticipantID Rapiddigitnaming Rapidletternaming Sightword Phonemicdecoding Elison Memoryfordigits Nonwordrepetition VerbalComprehension ConceptFormation
ROF58_TA 21 21 76 76 12 21 23 90 96

Run the scatter plot matrix again withot the outlier

Click to view full screen (open in new tab or copy link and paste in browser->download file -> open file)

Qualtrics Survey Data

Some Discriptive Info

Student Responses to the Questions

Summary of Yes/No Responses
Column Question Yes No
Q13 Received special Assistance in School 71 11
Q17 Stayed back in School 14 68
Q19 Took Foreign Language 79 3
Q23 Speech and/or Language Problems 31 51
Q25 Reading, Spelling, Writing, or Math Problems 73 9
Q27 Consistent Difficulty Recalling Familiar Words in Speaking 44 38
Q32 Learning Disability Diagnosis 66 16