Statistical analysis
At the end of the experiment and completion of data collection, all original data were entered into Excel 2010 for storage. After data entry was completed, the Excel data were imported into IBM SPSS Statistics 21.0 for statistical analysis. Statistical analysis mainly includes the following aspects.(1) Descriptive statistical analysis was performed on demographic and sociological variables, such as the ages of children participating in the experiment; and individual factors, such as the level of daily physical activity and frequency of watching natural videos using percentage or mean ± standard deviation.(2) Descriptive statistics were used to analyze the pre- and post-measurement values of the dependent variables, such as attention, using mean ± standard deviation. Based on the F-value, p-value, and effect size ɳp2 in the results of multivariate analysis of variance in the general linear model, improvement effects of the dependent variables of the pre- and post-tests of various combinations were compared.(3) On the bases of the F-value, p-value, and effect size ɳp2 of the repeated measures ANOVA in the general linear model, differences in the change of the dependent variable between groups of various combinations were tested.