This research was a methodological study, and permission was obtained from the developer to use and translate the original scale into Korean after approval was obtained from the Institutional Review Board of Hanyang University (IRB No. HY1-16-035-2). Details of the process are summarized in Table 1.

Stage I (Translation): Two translators conducted the forward translation into Korean independently of the original English instrument. Following the guidelines [19], two translators were selected who had different backgrounds; translator 1 was aware of the concept, ‘Usability and Heuristic’. The first translator tried to translate a more reliable equivalent form from the perspective of the measurement. Translator 2 (called a naïve translator), who was a professional (bilingual) translator who was unaware of these concepts being examined in the original instrument, performed a forward translation.

Stage II (Synthesis): The author reviewed each translation (T1 and T2) with the first translator and determined which parts had different meanings and words in comparison with the original instrument. We then discussed the selection of proper words in the context of meaning to reach a consensus. One common translation (T-12) was produced through the synthesis process. The second translator did not participate as a researcher in the meeting, but we could contact him by e-mail. However, there were no specific discrepancies or questions related to T2 during this stage.

Stage III (Back translation): Based on the guidelines of Beaton et al. [19], a professional translator who had no medical or usability background conducted a back translation (BT2), in which T-12 was translated back into the original language. Additionally, we did not provide any information on the original instrument to the translator to avoid information bias.

Stage IV (Expert committee review): The expert committee comprised six experts (Table 1). The experts were selected considering their experience related to translation work or their knowledge of the concepts being examined in SMASH. The review began via email, with an original developer verifying the differences between the back translation (BT1) and the original scale, and no major discrepancies were found. Then the expert committee reviewed and consolidated all versions to achieve equivalence between the source and the Korean version in terms of four aspects: semantic, idiomatic, experiential, and conceptual. As a result, of the 12 K-SMAHS principles, 11 except for K-SMASH 8 were revised in terms of the postposition, verb. Foreign words that were used as load words in Korea, such as the word ‘error’, were corrected into Korean expressions. Through this stage, we completed the prefinal K-SMASH.

Stage V (Pretesting): The prefinal K-SMASH was used to evaluate the mobile app, ‘Brake of My Mind, BoMM,’ which was developed for adolescent suicide attempters based on cognitive behavior therapy. It is recommended to have between 30 and 40 participants [19]; however, considering this scale is for heuristic evaluation, it was reviewed by a small group of experts who were experienced in usability testing, per the guideline introduced by Neilson [12]. Three experts participated (Table 2) and completed consent forms after being informed of the purpose of the study. The participants were provided the URL to download the app, which was available for Android phones, and they installed it on their own phones and performed a heuristic evaluation with the prefinal K-SMASH individually. Each heuristic was rated according to a 5-point rating scale from 0 to 4 for the severity of usability problems [12]. After the evaluation was completed, general characteristics were collected, and each participant was interviewed briefly by e-mail or telephone to verify his/her understanding and interpretation of each heuristic principle as well as the cultural relevance of the prefinal K-SMASH. Then, we revised and finalized the prefinal K-SMASH. All data were analyzed with SPSS 20.2.

The mean career time of the experts was 18.0 ± 2.64 years. All participants had experience with developing software systems from 1 to 10 times and with a usability evaluation at least once.

The results showed that there were no major differences among the severity ratings of the participants (Table 2). Regarding usability problems, the three experts offered similar or identical opinions for almost all the heuristics. Additionally, in brief interviews, all the participants answered that there were no critical discrepancies or inconsistencies with the cultural relevance of the prefinal K-SMASH. Some of the comments, such as expert suggestions to change the place of subjects or conjunctions in sentences, were revised with a Korean linguist.