# A Tertiary Study for Process Mining
## 3 Results--Findings
### Data Synthesis
#### 3.1.2 RQ2: What Are the Trends Relating to the Quality of Published SMSs/SLRs?
1.3 RQ3: What Are the Current Trends in SMSs/SLRs Relating to Guidelines, Data Sources, Types of Questions, and Number of Included Studies? Guidelines Most Frequently Cited for Conducting SMSs/SLRs in the Area of Process Mining  
The authors read the bodies of the included studies to extract the guidelines used. In the case that more than one of the guidelines was mentioned, all of them were accounted \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**Published in Journals**} & \multicolumn{2}{c}{**Published at Conferences**} \\ \hline
**S\#** & **Quality Score** & **S\#** & **Quality Score** \\ \hline S1 & 4.5 & S2 & 3.5 \\ S4 & 4 & S3 & 3.5 \\ S8 & 4 & S5 & 3 \\ S9 & 3.5 & S6 & 3 \\ S11 & 3.5 & S7 & 4 \\ S12 & 3 & S10 & 3 \\ S13 & 2 & S14 & 3 \\ S16 & 3 & S15 & 3.5 \\ S19 & 4 & S17 & 4 \\ S21 & 3 & S18 & 3 \\ S22 & 3.5 & S20 & 4.5 \\ S23 & 3.5 & S25 & 3.5 \\ S24 & 4 & & \\
**average quality score** & 3.50 & **average quality score** & 3.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: The average quality score for studies published in Journals and at Conferences. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**Published in Subscription Journal**} & \multicolumn{2}{c}{**Published in OA Journal**} \\ \hline
**S\#** & **Quality Score** & **S\#** & **Quality Score** \\ \hline S4 & 4 & S1 & 4.5 \\ S8 & 4 & S9 & 3.5 \\ S11 & 3.5 & S19 & 4 \\ S12 & 3 & S23 & 3.5 \\ S13 & 2 & S24 & 4 \\ S16 & 3 & & \\ S21 & 3 & & \\ S22 & 3.5 & & \\
**average quality score** & 3.25 & **average quality score** & 3.90 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: A comparison of the quality score for studies published in Subscription Journals and Open-Access Journals. for in the data extraction process. Regarding the guidelines that were more often used in SMSs/SLRs in the process mining domain, the guidelines by [PERSON] [11; 12; 31] are the most widely used. In addition, some other guidelines are followed, as illustrated in Table 5. Three of the studies do not report any specific guidelines for their research processes and syntheses (reported as n/a in the table below). However, they have been included in this study as they include a structure and methodology similar to the guidelines reported in the literature (search strategy, inclusion/exclusion criteria, quality assessment, data extraction and synthesis, etc.). Online Databases Most Frequently Used to Search for Primary Studies  
Thirteen different online databases were identified and used by the included studies. A complete list of the databases used in each one of the studies can be found in Appendix A (Tables A2 and A3). The picture below (Figure 4) summarizes the most preferred online databases: IEEE Xplore, Scopus, ACM DL, Science Direct, SpringerLink, and Google Scholar. It should be noted that in most of the cases, Google Scholar is used most as a source to identify additional studies, rather than as a primary source to locate studies for inclusion. Number of Primary Studies Included in Published SMSs/SLRs over the Years  
The SLRs/SMSs included in this study aggregate primary studies from 2002-2022. The smallest set of primary studies is six (in S15). The largest set of primary studies is 1278 (in S8). It is noted that the study with the smallest set of primary studies was a conference paper, whereas the study with the largest was a journal paper. As the research interest in PM grows, we cannot draw strict conclusions regarding the average number of primary studies in the studies included in this research (Table 8). For every study, the number of included studies depends on the research area and the research questions posed. An analysis of the number of primary studies for each of the studies included in this paper is shown in Table 6. It can be assumed that the number of primary studies included in each study correlates to the activity in the research area at a given time period. Figure 5 provides a graphical representation of the distribution of primary studies in each one of the 25 studies included.