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Selective Mutism Test – Do I Have Selective Mutism?
Research Dataset

Selective Mutism Questionnaire (SMQ)

Normative and Psychometric Statistics
STRONG N=368 α=0.895 42Countries
Abstract

Selective Mutism Questionnaire (SMQ) normative dataset currently contains 368 participant records collected between Jun 11, 2026 and Jul 11, 2026 .

This psychometric dataset currently includes 368 anonymous participant responses collected through voluntary participation. The observed mean score was 68.9 with a standard deviation of 15.02, indicating moderate score variability within the sampled population. Internal consistency reliability analysis demonstrated good reliability (Cronbach alpha = 0.895). Observed skewness (-1.12) and kurtosis (1.6) were examined as indicators of distribution quality. The distribution demonstrated mild departures from normality, although the overall score pattern remained broadly interpretable for preliminary normative purposes.

368
Participants
42
Countries
20
Scale Items
0.895
Reliability
Table 1
Dataset Overview
Assessment Selective Mutism Questionnaire (SMQ)
Research Status Established Dataset
Dataset Maturity 75 /100 — STRONG
Participants 368
Countries Represented 42
Items 20
Dimensions 5
Data Collection Period Jun 11, 2026 – Jul 11, 2026
Reliability α = 0.895
Note. The current Selective Mutism Questionnaire (SMQ) dataset contains 368 participant records collected from 42 countries. Dataset maturity reflects sample size, geographic diversity, and internal consistency reliability.
Table 2
Descriptive Statistics
Statistic Value
Mean Score 68.9%
Median Score 71
Standard Deviation 15.02
Variance 225.68
Standard Error 0.78
95% CI Lower 67.36
95% CI Upper 70.43
Minimum Score 10%
Maximum Score 93%
Observed Range 83
Note. M = 68.9, SD = 15.02, Median = 71. The 95% confidence interval ranged from 67.36 to 70.43.
Table 3
Sample Characteristics
Variable Summary
Participants N = 368
Countries 42
Age Information Available
Gender Information Available
Note. Demographic information was collected voluntarily. Participant counts may vary across demographic categories when information was not reported.
Figure 1
Global Participation
Note. Participants were represented across 42 countries. The largest contribution originated from US (36.7% of available geographic records).
Table 4
Percentile Norms
Percentile Score Interpretation
10th 49% Very Low
25th 61% Below Average
50th 71% Average
75th 80% Above Average
90th 86% Elevated
Note. Percentile values provide preliminary normative benchmarks derived from the current Selective Mutism Questionnaire (SMQ) sample.
Figure 2
Score Distribution
Note. Observed scores ranged from 10% to 93% (M = 68.9, SD = 15.02). Distribution characteristics included skewness (-1.12) and kurtosis (1.6). Distribution indices suggested mild departures from normality.
Table 5
Reliability Analysis
Metric Value
Cronbach Alpha 0.895
Reliability Classification Good
Participants 368
Items 20
Standard Error 0.78
Note. Internal consistency was estimated using Cronbach alpha. Reliability estimates are based on the current normative dataset and may change as additional responses are collected.
Item–Total Correlations
Item Item Quality r Rating Q7 0.72 Excellent Q2 0.72 Excellent Q4 0.7 Excellent Q15 0.67 Excellent Q9 0.65 Excellent Q5 0.63 Excellent Q19 0.62 Excellent Q16 0.61 Excellent Q8 0.61 Excellent Q13 0.61 Excellent Q12 0.61 Excellent Q14 0.59 Excellent Q18 0.58 Excellent Q17 0.53 Excellent Q10 0.51 Excellent Q11 0.5 Excellent Q6 0.48 Acceptable Q3 0.07 Problematic Q1 0.05 Problematic Q20 -0.06 Problematic
Item Analysis Interpretation

Item–total correlations were generally strong across the assessment, indicating that most items contribute effectively to the measurement of the underlying construct. The analysis identified3 itemsthat may benefit from future review.

Items Recommended for Future Review
  • Q1 (r = 0.05)
    I am able to speak freely at home.
  • Q3 (r = 0.07)
    I speak comfortably with close family members.
  • Q20 (r = -0.06)
    Even when I feel safe, I sometimes struggle to speak.
The lowest item–total correlation was observed for Q20 ("Even when I feel safe, I sometimes struggle to speak."; r = -0.06), indicating comparatively weaker alignment with the overall construct.
Table 7
Dimension Norms
Dimension Mean SD N
Anxiety 83.55% 18.42 368
Impairment 72.55% 22.6 368
Alternatives 71.78% 22.65 368
Consistency 58.83% 16.75 368
Speech 57.32% 18.29 368
Note. Dimension statistics summarize normative performance across the major constructs measured by Selective Mutism Questionnaire (SMQ).
Figure 5
Dimension Profile
Note. The highest observed dimension was Anxiety (83.6%), whereas the lowest observed dimension was Speech (57.3%). The observed difference between dimensions was 26.2 percentage points. Substantial variation was observed between dimensions.
Table 8
Dataset Growth Summary
Metric Value
Current Participants 368
Countries 42
Collection Start Jun 11, 2026
Collection End Jul 11, 2026
Months Recorded 2
Note. Growth statistics summarize cumulative participation throughout the observed data collection period.
Normative Data Notice

A total of 368 participant responses were available for this assessment. Dimension-level norms were calculated using 368 valid response records. Approximately 0 response record(s) were excluded from dimension-level normative calculations due to incomplete response patterns.

Limitations

Normative statistics are derived from voluntary participation and may not represent all populations. Reliability estimates, percentile norms, and dimension statistics should be interpreted in the context of the current sample and may change as additional responses are collected.

Ethical Statement

All records included in this dataset were collected anonymously. No personally identifying information is stored. Data are intended for educational, psychometric, and research purposes.

Recommended Citation

Selective Mutism Questionnaire (SMQ). Research Dataset. Retrieved from https://drdeenz.com/selective-mutism-test/statistics/

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