*2.6. Procedure*

The DAT program was continued for 10 months, with 45-min sessions held once a week. The sessions were carried out in groups of six children and aimed to improve functioning of memory and attention processes, to ensure adequate level of motivation, to increase sense of security and self-confidence in the presence of the dog, to boost the ability to cope with difficult emotions, to improve motor function and the sense of balance, and to reduce the sense of anxiety and loneliness through contact with the therapist and the dog. Some of the originally planned sessions had to be cancelled due to the patient's or the therapist's illness. All the DAT sessions were conducted in a therapy room in the premises of the facility. No therapy session had to be stopped earlier and no undesired events occurred. Needs of each patient and the goals of DAT (Table 1) were taken into account. The sessions in each of the five groups followed the same DAT program. In addition to that the children in the DAT group as well as the controls participated in a conventional treatment program, which included rehabilitation (individual practice focusing on endurance, correction, balance as well as strengthening of postural and respiratory muscles), speech therapy, as well as educational, artistic, and musical activities.


**Table 1.** Description of Dog-Assisted Therapy (DAT) sessions.

In our study, the DAT program was supervised by a team of experienced therapists for years providing services to children with intellectual disability.

### *2.7. Statistical Analysis*

Statistical analyses were performed using Statistica 13.1. software developed by StatSoft Polska. The obtained results of the examinations did not meet the criteria for parametric tests, i.e., normality of distribution of the relevant variables, due to which alternative non-parametric tests were applied in the analyses. Compatibility of the distributions with normal distribution was verified using Shapiro–Wilk test. Comparison of the results achieved by the children in the DAT group in the consecutive timepoints relative to the therapy (measurement over time) was performed using Friedman's ANOVA, Dunn's test being a suitable post-hoc analytic tool. Comparison of the results within the two groups (DAT and control) was performed using Mann-Whitney U-test. Differences in the therapeutic effects (short- and long-term) in the same group of subjects were examined using paired samples Wilcoxon test. Statistical significance was assumed if *p* < 0.05.

### *2.8. Sample Size*

The minimum size of the sample was calculated taking into account the number of children with intellectual disability attending the special educational facility in the Podkarpackie Region, Poland, annually. A fraction size of 0.9 was used, with a maximum error of 5% [32–35], a sample size of 58 children was obtained. The study involved 60 children. The following formula was applied to determine the minimum sample size:

$$N\_{\rm min} = \frac{Np\{\alpha^2 \cdot f(1-f)\}}{Np \cdot \alpha^2 + \alpha^2 \cdot f(1-f)}$$

*Nmin*—minimum sample size

*NP*—size of the population sampled

α—confidence level for the results, value of Z-score in normal distribution for the assumed significance level, e.g., 1.96

*f*—fraction size

*e*—assumed maximum error expressed with a fractional number, e.g., 3% is expressed as 0.03
