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Selective Mutism Test – Do I Have Selective Mutism?

Research Dataset

Selective Mutism Questionnaire (SMQ)

Normative and Psychometric Statistics
ROBUST N=1325 α=0.879 87Countries
Abstract

Selective Mutism Questionnaire (SMQ) normative dataset currently contains 1325 participant records collected between Jun 11, 2026 and Oct 31, 2026 .

This psychometric dataset currently includes 1325 anonymous participant responses collected through voluntary participation. The observed mean score was 68.5 with a standard deviation of 13.7, indicating moderate score variability within the sampled population. Internal consistency reliability analysis demonstrated good reliability (Cronbach alpha = 0.879). Observed skewness (-0.99) and kurtosis (1.77) were examined as indicators of distribution quality. The score distribution appeared reasonably balanced and did not suggest substantial departures from normality.

1325
Participants
87
Countries
20
Scale Items
0.879
Reliability
Table 1
Dataset Overview
Assessment Selective Mutism Questionnaire (SMQ)
Research Status Robust Dataset
Dataset Maturity 95 /100 — ROBUST
Participants 1325
Countries Represented 87
Items 20
Dimensions 5
Data Collection Period Jun 11, 2026 – Oct 31, 2026
Reliability α = 0.879
Note. The current Selective Mutism Questionnaire (SMQ) dataset contains 1325 participant records collected from 87 countries. Dataset maturity reflects sample size, geographic diversity, and internal consistency reliability.
Table 2
Descriptive Statistics
Statistic Value
Mean Score 68.5%
Median Score 70
Standard Deviation 13.7
Variance 187.62
Standard Error 0.38
95% CI Lower 67.76
95% CI Upper 69.23
Minimum Score 0%
Maximum Score 95%
Observed Range 95
Note. M = 68.5, SD = 13.7, Median = 70. The 95% confidence interval ranged from 67.76 to 69.23.
Table 3
Sample Characteristics
Variable Summary
Participants N = 1325
Countries 87
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 87 countries. The largest contribution originated from US (27.5% of available geographic records).
Table 4
Percentile Norms
Percentile Score Interpretation
10th 51% Very Low
25th 61% Below Average
50th 70% Average
75th 79% Above Average
90th 84% 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 0% to 95% (M = 68.5, SD = 13.7). Distribution characteristics included skewness (-0.99) and kurtosis (1.77). Distribution indices suggested no substantial departures from normality.
Table 5
Reliability Analysis
Metric Value
Cronbach Alpha 0.879
Reliability Classification Good
Participants 1325
Items 20
Standard Error 0.38
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 Q2 0.66 Excellent Q15 0.66 Excellent Q4 0.63 Excellent Q7 0.63 Excellent Q5 0.62 Excellent Q16 0.61 Excellent Q13 0.59 Excellent Q18 0.59 Excellent Q12 0.59 Excellent Q8 0.56 Excellent Q9 0.56 Excellent Q14 0.56 Excellent Q17 0.55 Excellent Q19 0.54 Excellent Q6 0.47 Acceptable Q10 0.41 Acceptable Q11 0.4 Acceptable Q3 0.07 Problematic Q1 0.05 Problematic Q20 -0.04 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 = -0.04)
    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 = -0.04), indicating comparatively weaker alignment with the overall construct.
Table 7
Dimension Norms
Dimension Mean SD N
Anxiety 83.88% 17.26 1325
Impairment 72.61% 21.53 1325
Alternatives 71.99% 20.43 1325
Consistency 58.81% 14.96 1325
Speech 55.05% 15.76 1325
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 (83.9%), whereas the lowest observed dimension was Speech (55.1%). The observed difference between dimensions was 28.8 percentage points. Substantial variation was observed between dimensions.
Table 8
Dataset Growth Summary
Metric Value
Current Participants 1325
Countries 87
Collection Start Jun 11, 2026
Collection End Oct 31, 2026
Months Recorded 5
Note. Growth statistics summarize cumulative participation throughout the observed data collection period.
Normative Data Notice

A total of 1325 participant responses were available for this assessment. Dimension-level norms were calculated using 1325 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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