Selective Mutism Questionnaire (SMQ)
normative dataset currently contains
155
participant records collected between
Jun 11, 2026
and
Jun 23, 2026
.
This psychometric dataset currently includes 155 anonymous participant responses collected through voluntary participation. The observed mean score was 70.41 with a standard deviation of 11.88, indicating moderate score variability within the sampled population. Internal consistency reliability analysis demonstrated good reliability (Cronbach alpha = 0.831). Observed skewness (-0.54) and kurtosis (-0.42) were examined as indicators of distribution quality. The score distribution appeared reasonably balanced and did not suggest substantial departures from normality.
155
Participants
24
Countries
20
Items
0.831
Reliability
Table 1
Dataset Overview
Assessment
Selective Mutism Questionnaire (SMQ)
Research Status
Established Dataset
Dataset Maturity
65
/100 —
STRONG
Participants
155
Countries Represented
24
Items
20
Dimensions
5
Data Collection Period
Jun 11, 2026
–
Jun 23, 2026
Reliability
α =
0.831
Note.
The current Selective Mutism Questionnaire (SMQ) dataset contains 155 participant records collected from 24 countries. Dataset maturity reflects sample size, geographic diversity, and internal consistency reliability.
Table 2
Descriptive Statistics
Statistic
Value
Mean Score
70.41%
Median Score
73
Standard Deviation
11.88
Variance
141.19
Standard Error
0.95
95% CI Lower
68.54
95% CI Upper
72.28
Minimum Score
40%
Maximum Score
91%
Observed Range
51
Note.
M = 70.41, SD = 11.88, Median = 73. The 95% confidence interval ranged from 68.54 to 72.28.
Table 3
Sample Characteristics
Variable
Summary
Participants
N =
155
Countries
24
Age Information
Available
Gender Information
Available
Note.
Demographic information was collected voluntarily. Participant counts may vary across demographic categories when information was not reported.
Age Distribution
Age Group
Participants
under18
23
18-24
8
prefer_not
5
25-34
5
Gender Distribution
Gender
Participants
Female
31
Male
6
Prefer_not
4
Figure 1
Global Participation
Note.
Participants were represented across 24 countries. The largest contribution originated from US (36.8% of available geographic records).
Country
Participants
Percent
US
57
36.8%
GB
14
9%
DE
12
7.7%
FR
10
6.5%
PH
7
4.5%
NO
6
3.9%
CA
6
3.9%
AU
5
3.2%
NL
5
3.2%
MD
4
2.6%
FI
4
2.6%
UA
3
1.9%
LT
2
1.3%
SE
2
1.3%
IT
2
1.3%
RO
2
1.3%
MY
2
1.3%
IQ
2
1.3%
JP
2
1.3%
IN
2
1.3%
ES
2
1.3%
IE
2
1.3%
RU
1
0.6%
SG
1
0.6%
Table 4
Percentile Norms
Percentile
Score
Interpretation
10th
53%
Very Low
25th
61%
Below Average
50th
73%
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 40% to 91% (M = 70.41, SD = 11.88). Distribution characteristics included skewness (-0.54) and kurtosis (-0.42).
Distribution indices suggested no substantial departures from normality.
Table 5
Reliability Analysis
Metric
Value
Cronbach Alpha
0.831
Reliability Classification
Good
Participants
155
Items
20
Standard Error
0.95
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 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 identified5
itemsthat may benefit from future review.
Items Recommended for Future Review
Q1
(r = -0.02)
I am able to speak freely at home.
Q3
(r = 0.13)
I speak comfortably with close family members.
Q6
(r = 0.22)
I worry about being judged when I talk.
Q17
(r = 0.29)
I have experienced these speaking difficulties for a long time.
Q20
(r = -0.14)
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 = -0.14), indicating comparatively weaker alignment with the overall construct.
Table 7
Dimension Norms
Dimension
Mean
SD
N
Anxiety
86.65%
13.33
110
Impairment
75.5%
18.94
110
Alternatives
71.39%
20.52
122
Speech
60.8%
15.94
110
Consistency
60.1%
12.92
110
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 (86.7%), whereas the lowest observed dimension was Consistency (60.1%). The observed difference between dimensions was 26.6 percentage points. Substantial variation was observed between dimensions.
Table 8
Dataset Growth Summary
Metric
Value
Current Participants
155
Countries
24
Collection Start
Jun 11, 2026
Collection End
Jun 23, 2026
Months Recorded
1
Note.
Growth statistics summarize cumulative participation throughout the observed data collection period.
Normative Data Notice
A total of
155
participant responses were available for this assessment.
Dimension-level norms were calculated using
122
valid response records.
Approximately
33
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/