Vocabulary retention in a spaced repetition longitudinal field study with high-school language learners Miguel A. Varela Submitted to Swansea University in fulfilment of the requirements for the Degree of Doctor of Philosophy Swansea University 2020 i Abstract Despite a large amount of research on spaced repetition in L2 courses to retain vocabulary over time, we still do not see its full implementation in everyday classrooms. Laboratory and field studies (on spaced repetition) have worked with participants of different ages and have demonstrated that information can be retained over time, even after several years. Some studies introduced spaced repetition in the classroom, but none of them integrated them fully as part of the curriculum for a whole year. This thesis describes an attempt to integrate spaced repetition in a high-school language course where students take a standard test at the end of the course. To investigate the implementation of spaced repetition, a main research study was conducted in which high-school students rehearsed 100 Spanish words every thirty days in eleven learning sessions. Participants were tested prior and during the treatment to monitor learning. Subjects were also tested 30, 60 and 70 days after the treatment to test vocabulary retention. Analysis of the results revealed that spaced repetition seems to play an important role in long-term vocabulary retention considering 70 days after the last learning session most of the words were still remembered. Further analysis revealed that the highest retention scores were obtained when the interstudy interval and the retention interval were equal in length. A final important finding was that lack of student motivation and engagement has emerged as a crucial factor that can negatively affect learning and consequent vocabulary retention. The implications of these findings for vocabulary learning research, and for vocabulary teaching in the classroom, are considered. ii Declarations and Statements DECLARATION This work has not previously been accepted in substance for any degree and is not being concurrently submitted in candidature for any degree. Signed .................. .................................................... (Miguel A. Varela) Date ...................... January / 28 / 2020.................................................. STATEMENT 1 This thesis is the result of my own investigations, except where otherwise stated. Other sources are acknowledged by footnotes giving explicit references. A bibliography is appended. Signed ................................... .................................. (Miguel A. Varela) Date ............... January / 28 / 2020......................................................... STATEMENT 2 I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organizations. Signed ................................ ..................................... (Miguel A. Varela) Date ......................... January / 28 / 2020............................................... iii Table of Contents Abstract ................................................................................................................................................... ii Declarations and Statements ....................................................................................................... iii Table of Contents ................................................................................................................................ iv Acknowledgements ........................................................................................................................ viii List of tables .......................................................................................................................................... ix List of figures ...................................................................................................................................... xii Abbreviations ...................................................................................................................................... xv Chapter 1: Introduction ............................................................................................................. 1 1.1 Relevance of vocabulary in foreign language learning ................................................ 1 1.2 Statement of the problem: Students forgetting vocabulary ....................................... 2 1.3 Repeating ......................................................................................................................................... 4 1.4 Why SR has not been fully implemented in daily L2 classrooms then? ................ 5 1.5 Conclusion ....................................................................................................................................... 6 1.5.1 Thesis outline ............................................................................................................................................ 6 Chapter 2: Literature Review .................................................................................................. 8 2.1 RI/ISI Combination to enhance long-term vocabulary retention ........................... 9 2.1.1 Introduction ............................................................................................................................................... 9 2.1.2 Bahrick (1979) ....................................................................................................................................... 10 2.1.3 Cepeda et al. (2008) ............................................................................................................................. 15 2.1.4 Küpper-Tetzel et al. (2014) .............................................................................................................. 21 2.1.5 Lotfolahi & Salehi (2017) .................................................................................................................. 25 2.1.6 Conclusion ............................................................................................................................................... 29 2.2 Teaching and learning .............................................................................................................. 30 2.2.1 Word gain vs. retention gain ............................................................................................................ 31 2.2.2 Real ecological teaching and learning ......................................................................................... 36 2.2.3 Innovative teaching methods: ......................................................................................................... 50 2.2.4 SR to help with authentic materials, motivation, and retention ...................................... 69 2.3 Discussion ...................................................................................................................................... 75 iv 2.3.1 RI/ISI findings ........................................................................................................................................ 75 2.3.2 Learning findings .................................................................................................................................. 79 2.3.3 Research Questions ............................................................................................................................. 81 Chapter 3: Replication of Johnson & Heffernan (2006) ............................................ 83 3.1 Introduction .................................................................................................................................. 83 3.2 Summary of the original study ............................................................................................. 84 3.3 Differences between the original vs. the replication study ...................................... 85 3.4 Intervention .................................................................................................................................. 86 3.4.1 Materials ................................................................................................................................................... 87 3.4.2 Participants ............................................................................................................................................. 90 3.4.3 Method ...................................................................................................................................................... 91 3.5 Results ............................................................................................................................................. 93 3.5.1 Vocabulary tests .................................................................................................................................... 93 3.5.2 Confidence tests .................................................................................................................................... 95 3.5.3 Retention test ......................................................................................................................................... 97 3.6 Discussion ................................................................................................................................... 101 3.6.1 Analysis of results from the original vs. the replication study .....................................