## 3 Results
### Countries Participating in the Study (RQ-4)  
We have created two country participation maps for WoS and Scopus to investigate visible trends for the countries participating in the study of ontology- and fuzzy-based IS  
Figure 5: The moderate keywords occurrence according to years. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Keywords** & **Retrieval** & \begin{tabular}{c} **Search** \\ **Engine** \\ \end{tabular} & \begin{tabular}{c} **Semantic** \\ **Query** \\ **Expansion** \\ \end{tabular} & \begin{tabular}{c} **Semantic** \\ **Relation** \\ \end{tabular} & \begin{tabular}{c} **Semantic** \\ **Retrieval** \\ **Similarity** \\ \end{tabular} & \
\begin{tabular}{c} **Semantic** \\ **Measurement** \\ **ment** \\ \end{tabular} &
\begin{tabular}{c} **Similarity** \\ **Measurement** \\ **Medium** \\ \end{tabular} \\ \hline collection & 6 & 3 & 0 & 0 & 1 & 0 & 0 & 3 \\ dataset & 4 & 0 & 0 & 0 & 2 & 3 & 0 \\ fuzzy & 3 & 0 & 5 & 2 & 5 & 0 & 0 & 0 \\ semantic & 3 & 0 & 5 & 2 & 5 & 0 & 0 & 0 \\ retrieval & 6 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ system & 5 & 3 & 1 & 0 & 1 & 0 & 0 & 0 \\ keyword & 8 & 4 & 0 & 0 & 1 & 0 & 0 & 0 \\ relevance & 4 & 1 & 0 & 0 & 0 & 0 & 0 & 0 \\ retrieval & 0 & 4 & 3 & 1 & 3 & 2 & 3 & 0 \\ semantic & & & & & & & & \\ query & 0 & 0 & 0 & 2 & 5 & 0 & 0 & 0 \\ expansion & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The co-occurrence matrix of the moderately occurring keywords in the ontology- and fuzzy-based IS field (the whole co-occurrence matrix is presented in GitHub ([[https://github.com/Jolantux13/Onto_Fuzzy_IS](https://github.com/Jolantux13/Onto_Fuzzy_IS)]([https://github.com/Jolantux13/Onto_Fuzzy_IS](https://github.com/Jolantux13/Onto_Fuzzy_IS)) (accessed on 25 February 2021)). field (RQ-4). _Note_ that we have developed two separate country maps for investigating differences in WoS and Scopus. Additionally, separate country maps were created because of inconsistent search models and query options of digital libraries, limited possibility to crawl libraries to retrieve results, limited access to bibliographic information of papers, inconsistencies when exporting search results from digital libraries, and differences in the formatting (i.e., author names, country names, etc.) [60]. Figure 6 presents the country map generated from the WoS dataset on ontology- and fuzzy-based IS. The five most occurring countries in the map are the following: Peoples R China (80), Spain (58), Italy (47), Taiwan (36), and India (31), where the number near the country indicates the number of papers published by a country. In Figure 6, countries are colored according to APY, which indicates the average publication year of the documents published by a country [57]. The yellow-colored countries present the new countries-contributors to the study topic. They are the following: Tunisia (2018), Pakistan (2018), Saudi Arabia (2018), and Egypt (2017). Since those countries have recently contributed to the ontology- and fuzzy-based IS topic, their APY is recent. Countries, such as the Peoples R China, Spain, Italy, England, the USA, and France, have a high volume of papers; therefore, their APY is in the middle according to the year distribution. Table 4 presents the co-occurrence of countries according to WoS. The columns and the rows of the matrix present countries, and the cells--the co-occurrence strength of two countries. The blank cell means the absence of a relationship between countries. The intensity of the green color indicates that countries tend to appear together. The more intense the green, the stronger the co-occurrence. As can be seen, the most co-occurred countries (RQ-4) are the following: Italy and Spain (13), England and the People R China (5), and Finland and Spain (5). Figure 6: The country map on the ontology- and fuzzy-based IS topic generated from WoS. Figure 7 presents the country map on the ontology- and fuzzy-based IS topic generated from the Scopus dataset.