DISCUSSION
The concept of resilience explains how humans exposed to stressful environments can adapt to stress and adversity. A precise measure of resilience is important for providing physical and psychological care in a range of situations. Particularly, Korean university students are experiencing difficulty in career and employment in the rapidly changing society, it is necessary to check resilience for nursing intervention. Compared to RS[
14] with 25 questions, which is used in domestic, RS-14[
17] with 14 questions has the advantage to simply evaluate resilience within a short time. This study attempted to confirm the validity and reliability of the RS-14 developed by Wagnild[
17], to explore its applicability to Korean university students, and verify its possible use for domestic resilience research.
Exploratory factor analysis identified two factors; all items were retained since item loadings were all above .40. Wagnild's research on the original RS-14[
17], and work by Nishi et al.,[
18] on the Japanese version of the scale, identified one factor, whereas Tian and Hong found two factors for the Chinese version[
19], although the items were configured differently to the present study. The two factors on the original RS scale were Personal competence and Acceptance of self and life [
14], with items 1, 2, 5, 6, 7, 8, 9, 11, 12, and 14 from the RS-14 loading on Personal competence, and items 3, 4, 10, and 13 loading on Acceptance of self and life. However, in the Korean version of the RS-14, items 10, 11, 13, 14, 12, 9, 7, and 4 load on Factor 1, and items 6, 3, 8, 1, 5, and 2 load on Factor 2. Baek et al.,'s research, which examined the validity and reliability of the Korean version of the CD-RISC, another resilience measure, found factors different to those of the original measure[
5]. The differences in factor structure found across studies may reflect cultural differences in the understanding of the resilience concept. A study by Hong[
26], which examined the meaning of resilience in Korean cancer patients, identified the following resilience characteristics: self-worth, self-efficacy, self-confidence, independence, optimistic and positive mind, strong will, and responsibility. Hong noted that is reasonable to view that as a result rather than characteristics of resilience to accept and embrace the adversity in life[
26]. Although Hong's research was conducted on cancer patients, the concept of acceptance of self and life in Wagnild and Young's research[
14] is the results rather than the property of resilience to Koreans. Baek et al.,[
5] mentioned that the difference in factor composition in the original tool and Korean tool could appear from the cultural difference, which was influenced by mutually different historical, social, geological environments, etc. The concept of resilience composition should consider social, cultural factors, also, the factors which compose resilience concept may have difference between groups [
4]. This highlights the fact that the present study reflects the unique environmental characteristics of Korea.
If we examine the cumulative explanatory power of each factor in this study, Factor 1, Self-confidence, explained 46.02% of the variance, and Factor 2, Self-control, explained 9.40%. The total variance explained by both factors is 55.43%. This is lower than the total explained variance of 61% in Tian and Hong's study[
19], but higher than the variance of 39.4% found by Nishi et al.,[
18], and the 53% reported by Wagnild[
17]. Total variance is used to decide the number of factors long with Eigenvalue. Standard of total variance had difference along with researches, the researcher considers total variance of this research is satisfactory, compared to previous researches.
For factors to be considered independent, their inter-factor correlation must be less than .50. In this study, the inter-factor correlation was high (r=.690). Chung[
20] examined the status of validity and reliability research related to the development of measures, there is almost no cases that rarely show correlation since most factors reflect concepts that consist of multiple aspects. All three papers that Chung reviewed showed a significant correlation between factors. The two factors in this research, Self-confidence, self-control, are desirable to be considered as subordinate concepts which compose the concept, resilience, it is considered that correlation between the two factors appeared. Also, it determines a concept by analyzing as one factor in the original tool, it is considered to influence the result of this research. Therefore, each RS-14 Korean version factor can be interpreted as having correlation within the concept of resilience rather than an independent zone.
Regarding concurrent validity, there was a high correlation between self-esteem and depression. Self-esteem is a positive or negative attitude towards the self; a person with high self-esteem respects and values themselves[
22]. This study showed a positive correlation between resilience and self-esteem, consistent with previous findings[
2,
5,
18]. Self-esteem is a personal factor that, along with self-efficacy and other personal traits, explains and contributes to resilience[
27], and is a key element in enhancing this ability[
28]. In the present study, depression showed a negative correlation with resilience, consistent with the findings of Kim and Min[
29], who found that resilience correlated highly with anxiety, depression, and alexithymia. Several other studies have reported that depression and resilience are negatively correlated[
5,
14,
18]. A Study by Lee and Kim[
1], that resilience displays positive correlation with university life adaptation, besides depression, also supports this research result. This study therefore indicates that the Korean version of the RS-14 has good validity and reliability.
Internal consistency is to check if responses are consistent between several questionnaires in order to verify the same concept, it is determined by α coefficient[
30]. This study showed a Cronbach's α of .905 for all items. For Factor 1, Cronbach's α=.862, for Factor 2, Cronbach's α=.841. For the original RS-14 scale, Cronbach's α was .93[
17], which is similar to the figure for this study. The α coefficient of reliability can range between 0 and 1, and values between .50 and .80 are considered adequate. The overall reliability, and the reliability for each factor in the Korean version of the RS-14, is high, indicating good internal consistency.
This study has verified the validity and reliability of this adaptation of the RS-14 for use with Korean university students. Therefore, this measure is an adequate tool to assess the degree of resilience; additionally, this shorter version of the scale is more convenient for survey subjects.
One limitation of this study concerns the difference between the present factor structure and those of previous studies. The two-factor structure for resilience in this Korean version of RS-14 needs further investigation using qualitative analysis. It would also be useful to explore further cultural differences in resilience. Previous work indicates that age is an important influence on resilience[
18], and Wagnild[
17] reports that RS-14 scores increase with age. The average age of the university students in this study was 21.9. Therefore, age may be an influence on the present findings, and this must be considered when using this new version of the scale. There is also evidence that gender affects resilience[
2,
18], so this needs to be confirmed with the present scale.
Therefore, additional research on this new scale should address several issues. First, the influence of age and gender on resilience needs examining in a Korean sample. Second, the present author is proposing to revalidate this Korean version of the RS-14 for a greater range of subjects, such as patients with chronic disease. Third, this study used a measure designed for use in a different culture, and the present scale is an adaptation for Korean subjects. It is necessary to continue the development of indigenous resilience measures that reflect the characteristics of the Korean culture.