A longitudinal study and a cluster analysis were conducted, using as reference the factors obtained in the exploratory factor analysis. A non-experimental (or ex post facto) methodology was employed, which is fundamentally characterised by the fact that it is an empirical search, in which the researcher has no direct control over the independent variables because these are neither modified nor submitted to experimental control (Latorre, Del Rincón & Arnal, 2005).

In this section we present the results of the longitudinal study carried out with the students of Early Childhood and Primary Education in two different courses (2nd and 4th year) of the degree. The results are presented and discussed, taking as a reference the demographic variables; then, the descriptive analysis based on each of the categories of the study is shown in Figures 1 to 6. Lastly, through the cluster analysis, the evolution of the perception on social networks along the degree is shown in Figures 7a, 7b and 8a y 8b.

For the demographic variables a frequency distribution of central tendencies was performed and for the rest of the variables, since the sam­ple was distributed in independent groups, a non-parametric analysis tech­nique was used (chi-squared).

Thereby, we formulated the null hypothesis, which states that “there are no significant differences in the longitudinal study between the groups of the second year of Early Childhood Education and Primary Education and the groups of the fourth year of Early Childhood Education and Primary Education for any of the categories analysed”, and the alter­native hypothesis, which stated that “there are significant differences in the longitudinal study between the groups of the second year of Early Childhood Education and Primary Education and the groups of the fourth year of Early Childhood Education and Primary Education for each of the categories analysed”.

The α confidence level was established at 0.05, in order to demon­strate the statistical decision on these differences in comparison with significance (p).

Next, Figure 1, we present the analysis of each category.

Figure 1 Figure 1 Relational category. Factors related to the use of social networks Source: own formulation

Relational category: this category comprises the factors related to the use of social networks and presents the responses obtained from the students of Early Childhood Education and Primary Education at two dif­ferent time points; i.e. an initial time point when they were studying the second year and a final time point when they were studying the fourth year. The longitudinal analysis was carried out with items 7-11, which cor­respond to who initiated them, interest level, frequency of usage, most used social network and reasons for using social networks.

In item 7 (“who initiated you in the use of social networks?”), from the responses obtained we can confirm that, as a remarkable finding, in most cases it is friends who introduce users to social networks, with 78% and 73% in the second year of Early Childhood Education and Primary Ed­ucation, respectively, compared to 74% and 74% in the fourth year of Early Childhood Education and Primary Education, respectively.

In item 8 (“how would you rate your interest in social networks?”), the responses obtained through the scale are mostly positive, with 66% and 53% for “normal” and “a lot”, respectively, in the initial time point, and 56% and 46% at the final time point. However, we observed that 12% of the students in Primary Education responded “little” or “nothing”.

In item 9 (“how frequently do you use social networks?”), there were three response alternatives: several times a month, several times a week and daily. In view of the results, we can confirm that the use of social networks takes place daily in both groups with 86% and 84% at the initial time point, compared to 84% and 64% at the final time point, which sug­gests that there are no significant differences in the groups through time.

In item 10 (“which social network do you use more frequently?”), most of the responses in both groups, Early Childhood Education and Pri­mary Education, were Facebook and Twitter, respectively. However, we must highlight the differences found in Twitter in the longitudinal analysis between the initial time point, with 84% and 70%, and the final time point, with 24% and 25%, respectively. The chi-squared value (χ² = 9.874), and the significance level associated to it (0.001), demonstrate that the imbalance and the variances observed are not due to chance.

Item 11 comprises the questions about the reasons for using social networks. The students of both groups showed clearly that the reasons were “entertainment”, with 74% and 70% at the initial time point com­pared to 68% and 79% at the final time point, and “keeping in touch”, with 82% and 74% at the initial time point compared to 48% and 71% at the final time point. The chi-squared value (χ² = 5.994), and the signifi­cance level associated to it (0.01), demonstrate that the imbalance and the variances observed are not due to chance.

For items 7, 8 and 9, provided that a confidence level (α) below 0.05 was established, it is not possible to demonstrate the differences observed between the variables in time, since the significance level ob­tained was higher than expected. Next, Figure 2, we present the analysis of Innovative category.

Figure 2 Figure 2 Innovative category. Usefulness of social networks Source: own formulation

Innovative category: items 12-17, related to the usefulness and rele­vance of social networks in education.

The responses to the question of item 12 (“do you think that social networks could be useful in education?”) were generally and mostly pos­itive in the two groups, both at the initial time point, with 88% and 94%, and at the final time point, with 82% and 94%, in Early Childhood Educa­tion and Primary Education, respectively.

In items 13-16, related to the usefulness of social networks such as Facebook, Twitter, Tuenti, Hi5, MySpace and LinkedIn, in sharing docu­ments and pictures, fostering communication between teachers and stu­dents, sharing knowledge among students, sharing knowledge among users and fostering communication in general; the responses for “sharing documents”, with 70% and 47% initially compared to 46% and 56% at the final time point, and “sharing knowledge among students”, with 52% and 45% initially compared to 32% and 60% at the final time point, were the ones selected by most of the participants in Facebook for both groups of Early Childhood Education and Primary Education. The chi-squared value (χ² = 9.498), and the significance level associated to it (0.002), demon­strate that the imbalance and the variances observed are not due to chance.

For item 17 (“which social networks do you consider to be relevant as a complement to face-to-face teaching?”), the responses of both groups were mostly for Facebook, with 82% and 67% at the initial time point com­pared to 72% and 70% at the final time point. Next, Figure 3, we present the analysis of educational category.

Figure 3 Figure 3 Educational category. Social networks improve the teaching-learning process Source: own formulation

Educational category: it comprises items 18, 22- 27, 30, and 33-36, with the response alternatives “noth­ing”, “little”, “normal” and “a lot”, which allowed to determine whether social networks improve the teach­ing-learning process in the classroom. A longitudinal analysis of the responses obtained from the students at two different time points is conducted. Most of the re­sponses were “normal” at the positive part of the table and corresponded to the initial and final time points of both groups, Early Childhood Education and Primary Education, respectively, as follows: social networks im­prove the learning process in the classroom (36% and 53% compared to 50% and 52%), social networks fos­ter synthesis capacity (58% and 53% compared to 50% and 48%), social networks encourages self-learning in students (36% and 47% compared to 50% and 42%), social networks improve cooperative learning (44% and 39% compared to 40% and 47%), social networks stimulate the interest of students in their own training (42% and 50% compared to 42% and 41%), social net­works are essential for quality learning (38% and 45% compared to 38% and 47%).

However, the alternative “a lot” was mostly se­lected in the item “teachers need training before us­ing social networks in their classroom” (48% and 58% compared to 32% and 68%), and the alternative “noth­ing” was mostly selected in the item “social networks must be forbidden in the classroom (42% and 56% compared to 68% and 50%). The alternative “normal” was mostly selected in the items “social networks are advisable for preparing classroom activities” (38% and 50% compared to 40% and 59%) and “the use of social networks is discouraged because they distract students from studying” (36% and 38% compared to 26% and 40%), and the alternative “little” was mostly selected in the item “teachers are ready to use social networks in their classroom” (66% and 47% compared to 22% and 52%).

It can be confirmed that there are no correla­tions between the variables observed and the specialty of the participants. However, it must be highlighted that there is a correlation between the groups anal­ysed with regard to the item “teachers need a lot of training before using social networks in their class­room”; the chi-squared value (χ² = 1.745), and the significance level associated to it (0.001), demonstrate that the imbalance and the variances observed are not due to chance.

Next, Figure 4, we present the analysis of item 36, which was conducted independently due to its high significance level.

Figure 4 Figure 4 Educational category. Social network with the greatest educational potential Source: own formulation

From item 36 (“in your opinion, of all the social networks, which one has the greatest educational potential?”), through the analysis of the results we can confirm that both groups, at both time points, selected mostly Facebook (74% and 70% compared to 68% and 69%) and Twitter (48% and 40% compared to 26% and 34%), leaving the other social networks behind with lower percentages; e.g. LinkedIn (8% and 11% compared to 6% and 11%). Figure 5 shows the distribution of the results.

Figure 5 Figure 5 Informative category. Level of information provided by social networks Source: own formulation

Through the non-parametric contrast analysis, we can confirm that there are no correlations between the relationships observed in time and the degrees of the participant; except for Twitter, for which a chi-squared value of χ² = 4.725 and the significance level associated to it (0.03) demonstrate that the imbalance and the variances observed are not due to chance.

Informative category: it comprises items 19- 21, 28, 29, 31 and 32, which are related to the level of information provided by social networks. The re­sponses given by the students corresponded to the alternatives “nothing”, “little”, “normal” and “a lot”. The highest scores were obtained in the response alternatives “normal” and “a lot” at the positive part of the table, and corresponded to the initial and final time points of both groups, Early Childhood Educa­tion and Primary Education, respectively, as follows: “social networks in education allow to have several conversations at the same time” (40% and 46% com­pared to 52% and 40%), “social networks in educa­tion allow to propose an idea in a few characters” (56% and 54% compared to 48% and 50%), “social networks allow to follow forums and people who provide interesting information about educational topics” (56% and 50% compared to 44% and 67%), “social networks do not provide anything new com­pared to other communication means” (56% and 50% compared to 44% and 67%), “social networks are strongly advised for keeping up to date” (68% and 53% compared to 32% and 59%), “social net­works are a good way of sharing and creating knowl­edge” (40% and 50% compared to 44% and 46%), “social networks are a good way of socialising” (68% and 59% compared to 46% and 59%).

Considering the results obtained, we can con­firm that, for both groups, social networks help the flow of information in the field of education.

Figure 5 shows that most of the students pre­ferred the alternatives “normal” and “a lot”, and no significant differences were found neither between the two degrees nor between the two time points of the longitudinal study. It can be inferred that the participants responded positively in most the items of the informative category. Provided that a confidence level (α) below 0.05 was established, it is not possi­ble to demonstrate the differences observed between the variables, since the significance level obtained was higher than expected.

With regard to the cluster analysis, the factor scores of the categories are presented in each of the axes. These categories are the starting point of the hi­erarchical cluster analysis and they allow to analyse the homogenous groups that are generated according to the degree and the year (2nd or 4th), with the aim of determining the influence of the time period lapsed on the perception of the students on social networks as didactic methods.

Next, we present the results of the cluster analysis, where two main groups were formed. For this analysis, the maximum distance for each category represented in each of the axes was adapted to the characteristics of the values of the factor model, as shown in Figure 6.

Figure 6 Figure 6 Cluster análisis Source: own formulation

Cluster 1 (Outsiders): students with lower scores for the educational potential of social networks in all the categories (innovative, informative, educational and relational).

With regard to the cluster analysis, the Ward model was used, and the results show that the “utilitarian” group has a greater proportion of people between 26 and 33 years of age and a later initiation age in the use of social networks; however, these are the ones who show a more positive evolution of their interest in social networks, and they consider them to be more relevant as a teaching complement. The “relational” group showed the sharpest decrease in the frequency of internet usage and the lowest interest in social networks, and they consider them to be less relevant as a teaching complement.

The evolution of “believers” and “outsiders” from the 2nd to the 4th year shows values of evolution and positive interest regarding social net­works, with a higher preference for the use of Twitter or LinkedIn over Facebook in the “believers” group, in contrast to the “outsiders” group.

Next, we present Figures 7a, 7b and 8a, 8b, which show the evolu­tion in the degrees of Early Childhood Education and Primary Education from the 2nd to the 4th year, as a function of the variables that show more significant changes of the clusters.

Figure 7a Figure 7a Evolution in the degree of Early Childhood Education Source: own formulation

Figure 7b Figure 7b Evolution in the degree of Early Childhood Education Source: own formulation

Figure 8a Figure 8a Evolution in the degree of Primary Education Source: own formulation

Figure 8b Figure 8b Evolution in the degree of Primary Education Source: own formulation

With regard to Early Childhood Education, there are major changes related to the usefulness of social networks and a greater relevance given to fostering self-learning. On the other hand, the changes decrease in “be­ing up to date”, “sharing and creating knowledge” and “proposing ideas in a few characters”.

With regard to the students of Primary Education, their evolution shows that, according to them, social networks improve “being up to date” and “proposing ideas in a few characters”. On the other hand, they do not evolve in “improving learning” and their own “interest on social networks”.

The students of both degrees, Early Childhood Education and Pri­mary Education show polarization and dispersion of their opinions about social networks, which may be related to a more critical attitude toward their advantages and disadvantages.

The use of technology is not a new phenomenon and many institu­tions of higher education employ management systems such as Blackboard and eLearn in their teaching-learning activities. However, these systems are under constant criticism, since they tend to foster an instructivist approach of teaching (Salavuo, 2008); thereby, social networks allow greater collab­oration among students, according to the pedagogical paradigm of social constructivism (Huijser 2008). We agree with Orlando R. Kelm (2011) in that it is in fact this collaboration potential of the technologies of social networks what makes them more appealing for being integrated into the teaching-learning process.

In the present study, we accept the alternative hypothesis that “there are significant differences in the longitudinal analysis between the groups of the 2nd year of Early Childhood Education and Primary Education and those of the 4th year of Early Childhood Education and Primary Education for the relational, innovative and educational categories”, as shown by the results.

The relational category corresponds to the factors related to the use of social networks. In both groups and at both time points, the social networks used most frequently are Facebook and Twitter. However, we must highlight the differences found for Twitter in the longitudinal analysis in the groups of Early Childhood Education at the initial time point, with 84% and 70%, compared to the results obtained at the final time point, with 24% and 25%, respectively. These results suggest that there was a decrease in the use of Twitter and an increase in the use of Facebook. With regard to the reasons for using them, “entertainment” was the most voted one at both time points, and “keeping in touch with friends and family” decreased in the group of Early Childhood Education.

The innovative category, related to the usefulness of social networks, is mostly positive in the two groups, both at the initial time point, with 88% and 94%, and at the final time point, with 82% and 94%, in Early Childhood Education and Primary Education, respec­tively. According to the participants, the most useful social networks are Facebook and Twitter for sharing documents and pictures, fostering communication between teachers and students, sharing knowledge among users and fostering communication in gen­eral. At the final time point, “Sharing documents and pictures” and “sharing knowledge” decreased in the groups of Early Childhood Education and increased in the groups of Primary Education. These data are con­sistent with the studies conducted by Edward J. Ma­loney (2007), Charlotte N. Gunawardena, Mary Beth Hermans, Damien Sánchez, Carol Richmond, Maribeth Bohley and Rebekah Tuttle (2009) and Jeff Hoyer, Ga­reth Thompson, Lisa LeBleu and Teresa Collard (2010).

The two social networks that are considered to be a potential complement to face-to-face teaching are Facebook and Twitter, although the students of Early Childhood Education preferred Facebook over Twitter at the beginning of the study, while at the end of it both groups chose Facebook.

In the educational category, there were differ­ences between the students of Early Childhood Edu­cation and Primary Education for the item “teachers need training before using social networks in the classroom”, in favour of those in Early Childhood Ed­ucation. These students consider that teachers must receive training in order to be able to use social net­works as didactic methods, and this evidence is con­stant through time, as shown by the data obtained in the longitudinal study.

In the informative category, no significant dif­ferences were found neither between the groups of Early Childhood Education and Primary Education nor between the two time points of the longitudinal study.

The cluster analysis allowed to analyse the ho­mogenous groups that appeared according to de­gree and year of study (2nd and 4th), with the aim of determining the influence of the time period lapsed on the perception of the students on social networks as didactic methods. In this regard, the “utilitarian” group has a greater proportion of people between 26 and 33 years of age and a later initiation into social networks; however, the students of this group are the ones who show a more positive evolution in their in­terest on social networks, and they also consider them to be more relevant as a teaching complement. The “relational” group showed the sharpest decrease in the frequency of internet usage and the lowest inter­est on social networks; they also consider these to be less relevant as a teaching complement. The evolution of “believers” and “outsiders” from the second to the fourth year shows values of evolution and positive in­terest on social networks, with a preference toward the use of Twitter or LinkedIn over Facebook in the “believers”, in contrast to the “outsiders”.

With regard to the Degree in Early Childhood Education, there were major changes regarding the usefulness of social networks and a greater relevance given to “fostering self-learning”. In contrast, the changes decreased for “being up to date”, “sharing and creating knowledge” and “proposing ideas with a few characters”. On the other hand, according to the participants of Primary Education, social networks are good for “being up to date” and “proposing ideas with a few characters”. In contrast, there is no evolu­tion for this group in “improving learning” and their own “interest on social networks”.

The students of both degrees, Early Childhood Education and Primary Education show polarization and dispersion of their opinions about social net­works, which may be related to a more critical attitude toward their advantages and disadvantages.

Although we understand that university stu­dents are much more predisposed to use technolo­gies in studying and learning activities beyond what centres, teachers and educational processes can offer, we highlight self-learning, through the use of social networks, as a significant finding for all the partici­pants, and especially for those in the Degree in Early Childhood Education.

With regard to advantages, the students of Early Childhood Education considered, at the beginning, the usefulness of social networks for “sharing documents and pictures”, and the results show that, through time, the opinions were more varied, with the “capacity of social networks to motivate students” being the most voted one. In contrast, the students of Primary Edu­cation did not show changes through time; most of them highlighted the motivating and sharing capacity of social networks in education.

Regarding disadvantages, there was a large number of students of Early Childhood Education who considered the distracting nature and bad use of social networks.

And lastly, we observed a more critical attitude from all the students, which probably shows their increasing expectations on the use of social networks from the beginning of their degree to the end of it.