Yes! We are always working to align our features to the latest research-based practices in language acquisition. In fact, we have a team of language researchers dedicated to this. Some of their work, as well as the work of others, can be found summarized in this blog post.
As we continue to research ways to increase the effectiveness of Duolingo, we will post updates on our website's efficacy page and our Twitter account--feel free to follow us to keep up with the latest findings!