Alternatively, some language learning tasks are suitable for software that is supported by databases, hence being able to deliver materials recorded from multiple native speakers.  I have a paper on the effect of using an adaptive training system to teach second language learners to recognize Chinese tones.  Perhaps  students got (simulated) one-on-one training, thus the time is used more effectively, on average their recognition scores improved by 8% after 2.5 hours of training.

https://www.researchgate.net/profile/Chilin_Shih/publications?pubType=inProceedings&ev=prf_pubs_inp

Hi  

if you need some ideas about second language learning , i think this book will help you

Thanks for your help! Avesta, which book are you referring to?

sorry for not uploading in the first time

Thanks all for your help!

Dear Laura

here are the publications:

http://www.lecforum.org/publications/Jenkins_Keefe_KAPPAN_Article_1.htm

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1310723/pdf/jaba00067-0035.pdf

http://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1078&context=edu_fac&sei-redir=1&referer=https%3A%2F%2Fscholar.google.co.th%2Fscholar%3Fq%3Dpersonalized%2Binstruction%2Blanguage%26btnG%3D%26hl%3Den%26as_sdt%3D0%252C5%26as_vis%3D1#search=%22personalized%20instruction%20language%22

http://isiarticles.com/bundles/Article/pre/pdf/22160.pdf

http://files.eric.ed.gov/fulltext/EJ800986.pdf

good luck with your research

a.