When a student learns something new in class, they make new synaptic connections .
However, there are strategies to help students retain learning , mostly those that are conducive to as many connections as possible, generally with other concepts, thus expanding the ‘web’ of neural connections, but also repeatedly accessing memory over time.
Peer explanations
The following learning strategies, all tied to research conducted over the past five years, have proven effective.
The first is peer explanations : when students explain what they have learned to their peers, fading memories are reactivated, strengthened, and consolidated.
This strategy not only increases retention, but also encourages active learning (Sekeres et al., 2016 ).

Space effect
Rather than covering a topic and then moving on, it’s about reviewing key ideas throughout the school year, putting perspective and context.
Research shows that students perform better academically when given multiple opportunities to review learned material . For example, teachers can quickly incorporate a brief review of what was covered several weeks earlier in current lessons, or use homework to re-expose students to earlier concepts (Carpenter et al., 2012 ; Kang, 2016 ).

Frequent practical tests
Similar to a strategy like regularly reviewing material, taking frequent practice tests can increase long-term retention and, as a bonus, help protect against stress , which often affects memory performance.
Labs can be low-risk and ungraded, such as a quick quiz at the beginning of a lesson or a question-and-answer quiz. (Adesope, Trevisan & Sundararajan, 2017 ; Butler, 2010 ; Karpicke, 2016 ).
Interleaved concepts
When similar problems are grouped together, students do not have to think about which strategies to use: they automatically apply the same solution over and over again. However, mixing and interleaving them forces students to think more and encodes learning more deeply (Rohrer, 2012 ; Rohrer, Dedrick, & Stershic, 2015 ).
Text + Images
It is often easier to remember information presented in different ways, especially if visual aids can make it easier to organize the information .
For example, pairing a list of countries occupied by German forces during World War II with a map of German military expansion can reinforce that lesson.
It is easier to remember what has been read and seen, rather than remembering only what has been seen or only what has been read (Carney and Levin, 2002 ; Bui and McDaniel, 2015 ).