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Expert Evaluation on Urgent Research on Heritage Language Education : A Comparative Study in Germany , Italy , the Netherlands , Portugal and Spain RESEARCH

Across and even within European states, heritage language education (HLE) for pupils with a migration background varies considerably, as do the political and academic discourses surrounding HLE. Due to the intensified public discourse around migration, educational opportunity and multilingualism, research on heritage languages (HL) and HLE has increased in recent years (Mehlhorn, 2020). However, there is still little agreement among scholars concerning the role of HLE for children’s linguistic, educational or personal development. Although studies suggest that support for heritage languages does not bear negative consequences, empirical findings on the optimal design and delivery of heritage language lessons (HLLs) are still lacking. How, then, should research be prioritised in different contexts? We consulted a large crossnational survey on research priorities for multilingualism and language education (Duarte et al., 2020) in order to uncover findings relating specifically to HLE. The findings derive from the rankings of research priorities by panels of expert participants (n = 300) in five European countries: Germany, Italy, the Netherlands, Portugal and Spain. The rankings indicate that research on HLE is considered important in all countries, albeit to a lesser degree in Spain. Research on the effects of HLE on the majority language and subject comprehension was deemed most important by the expert participants, or at least as urgent as effects on the heritage language itself. Experts also attributed importance to topics concerning HLE quality. Other findings point to country-specific priorities. We present the overall results from two sets of questions concerning research on HLE and attempt to offer qualitative interpretations of these findings. Expert Evaluation on Urgent Research on Heritage Language Education: A Comparative Study in Germany, Italy, the Netherlands, Portugal and Spain RESEARCH BARBARA GROSS ANTJE HANSEN SARAH MCMONAGLE JOANA DUARTE EDUARDO GARCÍA JIMÉNEZ NIKOLETT SZELEI ANA SOFIA PINHO *Author affiliations can be found in the back matter of this article CORRESPONDING AUTHOR: Antje Hansen University of Hamburg, DE antje.hansen@uni-hamburg.de


INTRODUCTION
This article describes the methods and results of a survey conducted in five national contexts to determine research priorities for heritage language education (HLE). In this survey, HLE refers to the provision of lessons in languages brought to host societies by immigration. Children attending HLE may have immigrated themselves or may be members of the second or third migrant generation. They usually acquire their heritage language (HL) in a limited number of contexts, such as family, peers or media. On account of such reduced input, abilities in the HL may be less well developed than those of children raised in the monolingual environment of the heritage country itself. However, as contexts vary from speaker to speaker, HL abilities generally exhibit significant variation -from literacy skills to receptive abilities to complete language loss. The majority language of the host society tends to become the dominant language as they enter educational institutions (Brehmer & Mehlhorn, 2018;Polinsky, 2015). The present study adopted the term 'heritage language', rather than 'migrant language', as it embraces speakers and learners of the second and third generations who were born in the host society (and not just speakers who migrated themselves) (see also Mehlhorn, 2020).
HLE differs considerably within and between European states, ranging from private lessons organised by language communities to formal instruction in the school system. Differences in academic, social and political discourses concerning heritage languages (HLs) and HLE therefore also exist. Differences notwithstanding, the implementation of HLE is generally debated in observable contexts. One argument in support of HLE (inter alia via education) is the interdependence hypothesis (Cummins, 2000), which claims a transfer of skills across different languages, thus having positive effects for the majority language as well as the HL. Another supporting argument is that systematic instruction facilitates academic and subject-specific language skills in ways that cannot be achieved via family communication only (Mehlhorn, 2017). However, the interdependence hypothesis remains contested by the time-on-task hypothesis, which is widely supported within educational practice. It argues that instruction time spent on HLs divests from the majority language, which is much more crucial to the general academic attainment of children.
Little expert consensus has been reached on such questions, and challenges to the qualitative provision of lessons persist as well. We thus sought to uncover the most pressing research topics concerning heritage languages lessons (HLL) and HLE. The study presented here represents a subset of a much larger enquiry to determine research priorities in the broad area of multilingualism and language education (Duarte et al., 2020) that contained two sets of questions on the effects and different aspects of HLE. Via a cross-national questionnaire conducted in Germany, Italy, the Netherlands, Portugal and Spain, priorities were voiced by experts in the research area of multilingualism and language education. From this larger study, we wanted to know how the experts responded to HLE as a research topic. Our research questions are thus: 1. What are the research priorities for the effects of HLLs on linguistic and other aspects of learning in the participating countries? 2. What are the research priorities for other aspects of HLL in the participating countries? 1 3. Are there differences in research priorities between the participating countries?
In the following section, we briefly describe the state of HLE in the five countries. We then present the research priorities for HLE for each country, statistically derived from the expert questionnaire. We review the similarities and differences between priorities for each expert panel, and offer possible explanations for these by drawing on contexts and discourses of HLE in the respective countries.

HERITAGE LANGUAGE EDUCATION IN THE PARTICIPATING COUNTRIES
The participating countries in the survey differ in terms of their migration patterns, HLE provisions, and research traditions. For example, Germany and the Netherlands have 1 "Other aspects" refer to pedagogical and organisational aspects of HLE, such as learner heterogeneity, the necessary teacher skills or the coordination of HLE with regular subject lessons. The list of topics can be found in Tables 8-12. experienced several periods of in-migration to varying degrees since the end of the Second World War. Italy, Portugal, and Spain were characterised more by emigration during the postwar years, with in-migration accelerating around the turn of the century. Types of immigration have depended on the histories and sociopolitics of the countries -for instance, much inmigration to the Netherlands, Portugal and Spain has been from their respective ex-colonies, while the so-called 'guest worker' schemes in Germany and the Netherlands recruited labour from mainly Mediterranean countries. While return migration has also been a feature of such schemes -especially for those workers whose countries acceded to the European Community -family reunification (for example in the case of Turks migrating to Germany after the recruitment ban of 1973) contributed to the establishment of heritage language communities.
Today, the five participating countries are host to diverse populations of economic migrants and those fleeing crises around the world, representing numerous heritage languages. Also, all of the countries recognise, to differing extents, some regional autochthonous languages (e.g., Frisian in the Netherlands; Danish, Sorbian, Frisian, and Romany in Germany; Mirandês in Portugal; German, Ladin, French, Albanian, and Slovenian in Italy; Catalan, Galician, Valencian, Basque, and Occitan in Spain). While this article focuses on allochthonous or heritage languages, it is important to also acknowledge the presence of regional minority languages as their salience often impacts discourses on heritage languages. Generally, in all five countries, policies are most concerned with fostering the majority language among linguistically diverse pupils.
The participating countries also have vastly different education systems and provisions for HLE. In Germany, each of the 16 federal states is responsible for its respective education system. The situation of HLE in Germany is therefore very heterogeneous with some states offering HLLs within the formal school system and others leaving them to community, consular or private initiatives. In the Netherlands, policies on HLs have shifted from a pluralistic approach to assimilation (Driessen & Merry, 2011). Today, at primary level, there is no offer of HLE within the regular school curriculum; instead HLE is offered by private operators or local language schools as an extracurricular subject. At secondary level, lessons in so-called 'new' foreign languages may be offered if there is demand from at least four students for a given language. In Italy, a mainly assimilationist approach to HL pupils is practiced. Each region has the autonomy to offer HLE in accordance with demands and resources. HLLs may be organised privately or at different school levels. In Portugal, HLE is still largely absent from compulsory education. Single efforts have been made by research projects and school-based initiatives to introduce bilingual classroom instruction in which the other language is a HL, however such arrangements have not yet been adopted systematically in the public education system. Rather, HLE is promoted informally in after-school activities. A similar situation is found in Spain with HLE organised mainly by migrant communities themselves, although some bilateral agreements envisage HLLs at selected mainstream schools. HLE for migrant pupils is not prominent on the social or educational agenda in Spain.
Across all five countries, HLE occupies a marginalised position (whether offered formally or informally), giving rise to a number of challenges in its provision. For instance, its extracurricular status renders participation burdensome, skills in HLs are often not certified, and HL teachers are isolated from general teaching staff. Moreover, HL teachers are differently qualified (if at all), and standardised materials are not always available. HLE thus presents the research field with a range of open questions as to its implementation and potential outcomes. There is no unanimous agreement on the role of HLE for language development or educational attainment. Moreover, as each country represents a highly specific context in terms of the characteristics outlined above, research breadth between the countries also differs considerably. In Germany, research interest in HL pupils began in the late 1960s (with emphasis on Turkish-speaking children) and has since expanded to include different HLs, intercultural and didactical approaches to integrate HLs in regular school subjects, multilingual subject content learning, participation in HLE as a factor for language competencies and attitudes towards HLE. Also, the Netherlands have a long history of immigration and research on heritage languages. This includes research on didactical approaches to value and integrate HLs into mainstream schools. At the same time regional minority languages (e.g., Frisian) have also been a prominent research topic. As HLE was abolished from primary schools in the early 2000s in favour of a Dutch-only policy, interest in research on HLE has only grown again in recent years.
In Italy, research on HLs mainly focusses on the role of these languages in the education system, how different HLs can be valorised, the benefits of HLs for intercultural dialogue, for learning Italian as the language of instruction, and for identity development, while research on the instruction of HLs itself is still in its infancy. In Portugal, HLs have been investigated in sociolinguistic and literary studies; however, in the field of education research, this is still an upcoming topic. If at all, HLs are considered in the frame of intercultural and plurilingual teaching approaches where ideally all of the students' languages are taken into account, including minority and heritage languages. The study of HLE is a thus new research field.
In Spain research traditionally focused on the interaction between the Spanish language and regional co-official languages like Catalan, Basque, and Galician. However, as Spain transformed into a country of immigration in the late 1990s/early 2000s, the research focus shifted towards language education for second-language learners of diverse backgrounds. Today, the relationship of heritage languages to identity development as well as attitudes towards Spanish and the co-official regional languages are popular research topics. HLE or didactical approaches to heritage languages are not yet relevant research topics. While HLE is slowly developing as a field of research, many open questions persist with respect to its implementation and impact. To the best of our knowledge no study or report has yet determined research priorities for HLE in any country. This study seeks to fill this gap and identify research priorities for HLE, not by deriving them from a literature review, but by consulting experts in the field.

METHODOLOGY
The larger expert survey, of which the present study forms a subset, was originally conducted in Germany in 2015/16 via the Delphi method of investigation to determine research priorities in the area of multilingualism and language education (Gogolin, Hansen, & McMonagle, 2017). The Delphi method aims to establish answers to (future) questions by consulting a panel of experts (Häder, 2002). Delphi studies are conducted in several rounds, the purpose of which is to reach consensus among the panel by displaying the group's results back to participants in the hope that convergence of opinion, determined by group average, may be reached. The Delphi method has been primarily used to predict future trends in economic and political sciences but has also been applied in education studies (e.g., Brosi, Krekel, & Ulrich, 2003;Kunina-Habenicht et al., 2012). In this Delphi study, identified experts in the field were asked to name urgent research topics across twelve pre-identified subtopics, one of them being HLE. Their open answers were evaluated, summarised and abstracted into closed research items in a quantitative questionnaire which were then sent back, in a second round, to the participating experts for evaluation. The quantitative questionnaire was translated first into English and then to Spanish, Dutch, Portuguese, and Italian for evaluation in those contexts. The selection and wording of HLE-related research topics was thus based on the German questionnaire and translated in cooperation with researchers from the other four participating countries. The results produced research priorities for all research items to emerge from the German study and across four additional national contexts. Here we report on the research priorities for HLE in all five settings.

SAMPLE AND SAMPLING METHOD
The participating countries in the large, cross-national survey were not selected systematically, but through a network of researchers who had expressed interest in implementing the German survey in their own contexts (see Duarte et al., 2020). While this points to a weakness in the overall methodology, the participating countries provide enough differentiation for us to identify trends in HLE research.
The survey was sent to those considered experts in the field of research on multilingualism and language education. This comprised mainly academics, but also educational practitioners and policymakers (see Table 1). The expertise was characterised by comprehensive knowledge and experience in the research area of multilingualism and education. The expert participants were contacted through the networks of the authors (all of whom are researchers in the area themselves), via topic-related conference programmes, journals, university websites and research organisations. Further participants were recruited via snowball sampling (e.g., Berg, 2006), meaning that questionnaire respondents were asked to name further potential participants with the necessary expertise to complete the survey. The researchers subsequently contacted these named experts and invited them to participate. Altogether, 300 experts from Germany, the Netherlands, Italy, Portugal, and Spain completed the online questionnaire. Their background data showed that most of them had been working in the area of multilingualism and education in academia (see Table 1) for 11+ years (see Table 2), supporting the assumption that they are indeed experts with substantial knowledge on the matter. The participants' research backgrounds were primarily in education or linguistics (or both), and to a lesser extent in psychology and sociology (see Table 2). As the research field of multilingualism and language education is interdisciplinary in nature, the aim was to assemble a panel that comprised experts from different academic disciplines. We acknowledge that the experts' response behaviour might reflect and be influenced by their academic background and this may have led to bias in the results. However, it was not the aim of the study to create a stratified sampling for academic disciplines, as academic backgrounds in the field of multilingualism and language education differ from country to country. Informed consent of the participants was obtained through the questionnaire.

DATA PROCESSING
The cross-national survey contained two sets of questions on HLE. The first focused on research on the effects of HLLs on certain dimensions, such as subject comprehension (i.e., the understanding of content and concepts taught in specific school subjects), motivation and well-being (i.e., an affective dimension) and the development of skills in different languages (such as the heritage, national or foreign languages), the second on other aspects of HLLs (specific items are detailed in the tables in the results section, e.g., Tables 3 and 8). Participants were asked to determine the importance of conducting research on a given topic on a 4-point  indicate whether a topic is sufficiently researched or whether they were unable to assess it. Very few participants considered any of the named topics to be sufficiently researched. These responses were not included in the calculation of the mean values as their priority could not be assumed.
For each topic, the mean was calculated using SPSS. Rankings could then be compiled according to the means. The higher the value of the mean, the greater the importance to conduct research on the given topic, as determined by the participating experts. Throughout the study, and also for HLE, many topics received high means indicating a general need for research in the areas of multilingualism and language education. Topics with a mean of below 3 are thus considered less important than others. The standard deviation (SD) was calculated as an indicator of agreement between participants. One-way ANOVAs were conducted to analyse country differences.

RESULTS
Here we present the research priorities for HLE to emerge from the five contexts. While the method of enquiry only allows for a statistical group decision on research priorities, we attempt to interpret the statistical findings by drawing on the situation and discourse of HLE in each of the five countries.

RESEARCH PRIORITIES FOR THE EFFECTS OF HLLS Germany
The means of the effects of HLLs on subject comprehension, motivation/psychological wellbeing, the heritage, and the German language all received high values. This ranked importance might be because there is still little research on the effects of HLLs in Germany in general. The curricular goals of HLE in Germany focus explicitly on the development of the HL (as well as intercultural competence and knowledge of the relevant country). However, the German experts ranked research into subject comprehension over effects on the HL, and effects on the German language are almost on a par with the HL. Neither of these constitute major goals of HLLs in Germany. Thus, whether the interdependence hypothesis or the time-on-task hypothesis applies in the context of HLE, remains an open question in Germany. One of the reasons why such research might be considered important is to justify HLE in the sense that it does not obstruct and even possibly supports the development of the majority language and subject comprehension.
Research into the effects of HLE on motivation and psychological well-being is ranked second. This may be due to the claim that the fostering of HLs contributes to such conditions in multilingual learners (Cummins, 2000), although this has yet to be empirically validated. Meanwhile, research on the effects of HLE on foreign language skills is considered less important. This might be because such an influence is not considered relevant or because experts in foreign language teaching/learning were not well represented in the expert sample (see Table 3). Statistically significant differences were found between the items' means (F = 11.30, p < 0.001).  Table 3 Research priorities for the effects of heritage language education in Germany.

RANKING
* N only includes those participants who indicated a priority from 1-4. Values differ as the options "is sufficiently researched" and "unable to assess" were not incorporated when calculating the means. Moreover, some participants dropped out during the course of the questionnaire. This applies to all countries. ** "Is sufficiently researched" and "unable to assess" report the frequency of participants who have chosen this answer option. This applies to all countries.

The Netherlands
The Dutch rankings are similar to those of the German sample with research on subject comprehension considered most important. Research into the effects of HLE on the majority language is ranked higher than that on the HL. It seems, then, that this also remains an open research question in the Netherlands, with HLE perhaps having to justify its implementation without negative or possibly positive effects on Dutch. The impact of HLE on the development of the heritage language ranks 4 th and is considered less important than almost all other dimensions.
Research on the effects on motivation and psychological well-being is considered important, while research on the effects on foreign languages is not found to be a priority (see Table 4). Statistically significant differences were found between the items' means (F = 13.58, p < 0.001).

ITALY
In Italy, there is as yet little research on the effects of HLE. This could explain why all the topics were considered important with similar means. Interestingly, research into the effects of HLE on HLs themselves is ranked slightly lower than skills development in the Italian language.
Again, there appears to be a need to establish the role of HLE in either hindering or supporting skills in dimensions other than the heritage language itself. Research on the effects of HLE on foreign languages received more prominence among the Italian sample than its German or Dutch counterparts (see Table 5). Statistically significant differences between the items' means were not found (F = 0.673, p = 0.54).

Portugal
In Portugal, research on the effects of HLE on the Portuguese language was considered most important. This can be explained by the fact that the development of Portuguese as a second language currently dominates educational discourses there. Research into the effects of HLE on the psychological well-being of students, subject comprehension and the HL are also considered important, however almost all dimensions are considered more or as important as the effects of HLE on the HL itself. Similar to Italy, the means for all dimensions are relatively   high. Effects on the development of foreign languages is lowest in the ranking, but with a mean of 3.33 not considered unimportant (see Table 6). Statistically significant differences were found between the items' means (F = 2.51, p = 0.48).

Spain
Compared with the other countries, the different dimensions accumulated overall lower means. The Spanish experts thus attributed generally lower importance to research on HLE. This might be explained by the lack of a salient discourse on HLE in Spain. However, the rankings indicate similar trends to the other countries. Research on the effects of subject comprehension is considered most important, and the majority language trumps the HL in terms of research priorities. Indeed, the latter ranks lowest with a mean of 2.91. Interestingly, research on the effects on foreign languages was considered an important research topic. This might be due to the fact that many experts on multilingualism in Spain come from the discipline of foreign language teaching and thus attribute relevance to this (see Table 7). Statistically significant differences between the items' means were not found (F = 1.83, p = 0.37).

RESEARCH PRIORITIES FOR OTHER ASPECTS OF HLE Germany
Looking at other research topics relevant to HLE, the German experts found research on the effective organisation of lessons in light of the linguistic heterogeneity of the student body to be most important. Due to the varied abilities of HL learners, this is claimed to be a central challenge in HLLs (Brehmer & Mehlhorn, 2018). Other topics considered important refer to the quality of HLLs, such as the required qualifications of HL teachers. Little research exists on this despite an awareness of the disparate nature of teacher qualifications and forms of employment. Quality is also addressed in the higher ranking of research into the characteristics of good HLLs (4 th place).
Research into the effects of coordinating HLLs with mainstream lessons was also ascribed significance. Gürsoy and Roll (2018) claim that such coordination benefits both content and language learning by making use of transfer, however more empirical findings are required.  Topics considered less important concern organisational aspects, such as the integration of HLL into the mainstream curriculum, effective forms of cooperation between HL and mainstream teachers, and research on organisational forms of HLL. One way to raise the status of HLLs is to offer them as mainstream foreign language lessons that are open to all students, regardless of family language (Küppers & Schroeder, 2017), yet research on this is considered less urgent (see Table 8).
Statistically significant differences between the items' means were not found (F = 0.528, p = 0.47).

The Netherlands
Most important for the Dutch experts is research concerning the inclusion of students with other first languages into HLLs. This item signifies an opportunity for HLE to escape its marginalised position by being offered more broadly. The inclusion of students of other HLs would certainly increase the already existing linguistic heterogeneity of such lessons. Research on this topic was, with a mean of 3.41, also considered important. The Dutch experts rank research into the quality of lessons (such as the necessary teacher qualifications, 2 nd place, and the characteristics of 'good' HLLs, 5 th place) higher than research on organisational aspects. Another important research topic was found to be the impact of coordinated HL and regular lessons on linguistic competencies, a topic which also concerns the content and quality of lessons (see Table 9). Statistically significant differences were found between the items' means (F = 2.54, p = 0.01).  Table 9 Research priorities for other aspects of heritage language education in the Netherlands.

Italy
In Italy, experts awarded high priority to research on ways of including students who speak other heritage languages and the necessary HL teacher qualifications. Research on the effective organisation of lessons in light of the linguistic heterogeneity of the student body was considered less, but still somewhat, important (5 th place). Other important research topics included the acknowledgment of achievements and participation in HLLs, and the integration of HLL into the regular curriculum (3 rd and 4 th place, respectively). Together, these topics refer to a general interest in the inclusion of HLLs into mainstream curricula. Research on the effects of coordinated HLLs and regular lessons, as well as collaboration between the relevant teachers, is less important for the Italian experts, as is research into organisational aspects. Notably, however, research topics concerning HLE in Italy received higher means when compared with the other countries in this study (see Table 10). Statistically significant differences were found between the items' means (F = 2.06, p = 0.04).

Portugal
Experts in Portugal deem generally important the coordination of HL with regular subject lessons, with two research topics on this aspect (collaboration between teachers and the impact of such coordination on linguistic competence) ranked highest. Research on the integration of HLLs into the regular curriculum was considered less important, perhaps because it does not appear to be an option in practice (for the time being). Otherwise, research on the different types and organisation of HLLs was considered relevant, possibly given that not much is known about the forms of such lessons in Portugal. Topics regarding lesson quality (e.g., linguistic heterogeneity and teacher qualifications) were also attributed significance. This shows an interest in improving HLE in Portugal. At the same time, however, research on the characteristics of 'good' HLLs was considered less urgent. Research into the inclusion of students with other first languages into HLLs was ranked relatively higher (see Table 11). Statistically significant differences between the items' means were not found (F = 0.90, p = 0.52).

Spain
In Spain, the overall lower means underline that HLE constitutes a generally less important research topic than in the other participating countries. The Spanish participants considered research into the organisation of lessons given the linguistic heterogeneity of the students most relevant. The topics of coordinating HL with regular lessons and collaboration between the respective teachers seems to be of interest in Spain (2 nd and 3 rd place, respectively). Research on the necessary teacher qualifications ranks 4 th but is -with a mean of 2.97 -not of high priority; the same applies to the remaining topics. Research on the characteristics of 'good' HLLs ranks lowest with a mean of 2.52 (see Table 12).
Statistically significant differences between the items' means were not found (F = 1.78, p = 0.08).

DIFFERENCES IN RESEARCH PRIORITIES BETWEEN THE PARTICIPATING EXPERT PANELS
One-way ANOVAs were conducted to complement the rankings and to determine significant differences between the participating panels. The dependent variables are represented by the questions 'How important is it to research the effects of heritage language lessons on…' and 'How important is it to research the following aspects of heritage language lessons…'. 'Country' denotes the independent variable. A statistical significance was found between at least two countries where p < 0.05. The equality of error variances across groups (countries) for each item was confirmed by the Levene's test. Since multiple analyses were conducted on the same dependent variables, the Bonferroni correction was performed in order to avoid spurious positives. That correction sets the α value for the entire set of n comparisons equal to α by taking the α value for each comparison equal to α/n. In this study, the α value equals .05 and there are 14 comparisons so that any observed p-value becomes significant if it is less than .0036 (.05/14 = .0036). The Bonferroni correction was also used for the post-hoc comparisons.  Means did not differ significantly on subject comprehension and motivation/psychological wellbeing, as research on those dimensions was considered important in all five contexts.
Bonferroni's post-hoc test was carried out to pairwise compare countries for those items where significant differences were found (see Table 14; the country/ies for which a significant difference occurred is/are listed in the cells). This was the case for research on the effects of HLE on skills development in foreign languages. Both the German and Dutch panels considered this research topic less important and with relatively low means. The Italian experts considered research on this topic to be important with a significant difference to both Germany and the Netherlands. Concerning research on the effects of HLE on the development of skills in the majority language, a significant difference was found between Portugal and Spain; the Portuguese panel deemed this topic to be most important (M = 3.80), with the Spanish experts attributing less importance to it (M = 3.06).
With regard to research on the effects of HLE on skills development in the HL, there are significant differences between Spain, whose experts considered this topic least important, and Germany, where the topic received higher priority.
For the second scale (research on other aspects of HLE), the one-way ANOVA revealed statistically significant differences between country panels for all items (see Table 15).  Significant differences only occurred between Spain and the other countries, as the Spanish panel considered HLE-related research topics to be generally less important (see Table 16).

DISCUSSION AND CONCLUSION
We sought to establish a set of research priorities for HLE by analysing expert responses to relevant questions in a large, cross-national survey on multilingualism and language education (Duarte et al., 2020). Our findings and analysis show that HLE is perceived to be an important research topic among a sample of experts in the field of language education and multilingualism. The collation of feedback from an expert panel on pre-defined topics does not reveal, however, general perceptions of the need for research in this area. Nor can it provide information on priorities in the various national education policy agenda, which are influenced by competing interests. Experts in Germany, the Netherlands, Italy, and Portugal rated the need for research on HLE as more important than those in Spain. This may be because, in Spain, there is little public discourse around a topic considered internal to the respective HL communities. In the other countries, HLE has gained a certain visibility and importance, albeit to different degrees, in public and academic discourses, which in turn raises the perceived necessity to conduct research on it.
In all countries, research on the effects of HLE on subject comprehension or the majority language was found to be more or as important as research on the HL itself. We consider two plausible explanations for this. First, there is as yet little consensus on whether HLE positively or negatively impacts skills in the majority language with conflicting claims persisting. Second, as both these dimensions are critical to educational attainment, research on the effects of HLE on them may serve to legitimise HLE in monolingually perceived societies.
Although studies show that HL learning does not hinder -but may even support -the language of schooling (Brehmer & Mehlhorn, 2017;Cummins, 2000;Krompàk, 2010;Möller, Hohenstein, Fleckenstein, Köller, & Baumert, 2017;Riehl, 2020) and subject comprehension (Schüler-Meyer, Prediger, Kuzu, Wessel, & Redder, 2019), clearly more research is desired in all five national contexts. These findings are noteworthy, however, when we consider that the relevant HLE curricula -where existing -do not outline majority language or subject comprehension skills as central aims. Rather, HL development is the central objective of HLE. It is therefore remarkable that research into the effects of HLE on the HL or the characteristics of 'good' HLLs are not regarded as particularly urgent among the experts consulted. It may be assumed that HLE automatically has positive effects on the relevant language. However, this is not necessarily the case, particularly when teachers are not appropriately qualified, when skills are not certified, or when HLLs are offered erratically or outside of school. In her study on the influences of biliteral skills of students with Turkish, Italian, and Greek backgrounds in Germany, Riehl (2020) ascertained that extracurricular HLE only had a positive impact on writing skills in the HL when attended for seven years or more. This is explained by the weak integration of HLE into school procedures and teachers who are not 'familiar with German teaching methods and language G* N I P S  didactics' (Riehl, 2020, p. 17). Similar conditions are likely to occur in other countries, too, yet this research topic was not regarded as urgent across the national contexts represented in this study, as impacts on subject comprehension and the majority language were considered more important to research. It is understandable that research on the effects of HLE on the majority language and subject comprehension is considered relevant as such a relationship has been suggested in academic studies (Cummins, 2000). However, we argue that in order to remove HLE from its marginalised position and to establish it as modern language learning, focus needs to be shifted away from its impact on the majority language and towards an improvement in HLE in its own right.
Generally, the results of the scale concerning other aspects of HLE indicate a desire for the improvement of HLE. In Germany and the Netherlands, research on lesson quality is considered more important than research on organisational aspects. Research on teacher qualifications and the linguistic heterogeneity of students, two factors that impact lesson quality, are considered important by all expert panels (although less so in Spain). Research on the effects of HLE on motivation and psychological well-being also constitutes an important research topic in all countries, presumably due to the fact that positive impacts have been suggested by supporters of HLE despite a lack of empirical evidence (Cummins, 2000).
Our analysis also reveals country-specific priorities. Whether HLE impacts the development of foreign languages was not considered a research priority in Germany and the Netherlands, however it was attributed importance in Italy, Portugal and Spain. Research on the inclusion of speakers of other HLs into HLE is deemed particularly important by the Dutch and Italian experts. Attempts to interpret these findings reveal the constraints of the survey method used, however. While we can see how expert participants responded to the research items, we do not know why they responded in such a way (see also Duarte et al., 2020). There may have been particular biases in expert panels that led to these stark findings. We would suggest, for future research, that a qualitative round of consultation take place in order to assist with the interpretation of the statistical results. Much of our interpretation has had to rely on previous knowledge of the different migration patterns, education systems, research traditions and (sometimes contradictory) findings, and the salience of a given topic in respective discourses. We also cannot be certain why some experts dropped out in answering the questionnaire, but can only assume that the long, demanding, and time-consuming questionnaire -as some experts relayed to us in open comments -may have influenced the willingness of the respondents to participate to the end of the survey.
The strengths of this method are that research priorities can be determined quickly. Moreover, the results represent a collective perspective as determined by a group of experts and are not the opinions of single researchers. While the comparison of different national contexts reveals differences in priorities vis-à-vis HLE, similarities in the prioritisation of research into the impact and quality of HLLs occur. Furthermore, the survey can be adapted and repeated in other countries to build a richer picture of those differences and similarities. These results could contribute to a European research agenda for HLE that addresses the research needs of several countries as they face similar challenges and open research questions.