School is for learning. But ironically, one of the things that people don’t really learn to do well in school was to learn. We are taught rote memorization and told to absorb it for arbitrary tests without being taught how to effectively absorb the material. And it seems as the methods we were actually taught in school aren’t all that effective. In a meta-analysis (a study analyzing other studies) published several years ago, 10 of the most popular learning techniques were studied and their effectiveness were ranked. The methods were categorized as low, moderate, or high in terms of utility (effectiveness) in absorbing learned material. Highlighting/marking/underlining, summarizing, and rereading—-all popular study methods taught in school—-registered as low utility.
Each method was then evaluated as either low, medium, or high in terms of utility (read, effectiveness).
High Efficiency Study Methods
Practice testing and distributed practice received a high utility assessment because they benefit learners of many age groups and abilities, and have been shown to boost academic performance across a multitude of testing conditions and testing materials. Additionally, high utility study methods do not require extensive training in relation to their gained benefits.
Practice testing (High)
This should come as no surprise—practice testing has been lauded by learning experts as one of the best ways to retain information. Practice testing has over 100 years of research to back up its effectiveness. Simply put, it works.
Practice testing doesn’t need to actually be an actual test and in a testing environment. In actuality, you can test yourself anytime, anywhere, and with anything. You can test yourself in your head by asking yourself questions and answering them. You can also test yourself by using flash cards. You can test yourself by doing practice problems without the aid of notes or textbook material. And yes, you can test yourself by setting yourself up in a testing environment.
Two theories have been put forth as to why testing works: 1) testing enhances retention by triggering elaborative retrieval processes by accessing your long-term memory and retrieving associated information and 2) testing facilitates the encoding of more effective mediators via cues and targets. Additionally, recent evidence suggests that practice testing also improves the ability of students to mentally organize their knowledge, and thereby increasing the speed and efficiency of the information retrieval process.
Practice testing is highly effective because it is reasonable with time demand, doesn’t take a whole lot to learn how to do, and works for all types of tasks and subjects.
Tips for practice testing: Studies show that immediate retesting without time between tests does very little good in increasing learning. Rather, practice testing should be done when enough time has elapsed between practice tests.
Distributed practice (High)
Distributed practice is the method of dividing your studies over time intervals rather than doing it in one large chunk. This is why cramming for tests does not work; studies have repeatedly shown that distributed practice is better for material retention and absorption. The reason distributed practice works is because it gives the brain time to absorb the information by switching back and forth between focused and diffused mode of thinking. The evidence is pretty clear that spacing your studies is important to remembering what you learn.
A study in 1979 showed that students who distributed 6 study sessions with an interval of 30 days between each session did the best when a test was administered 30 days after the 6th session. The students who distributed their 6 sessions with 1 day between each session did slightly worse on the final test (also given 30 days after their 6th session), but did better than the first group in all the tests given prior to the final test. And the people who did not allow a day to lapse before restudying fared the worst. They did dramatically worse on the final test than the first two group.
Tips for distributed practice: Although it would be nice to let 30 days sit between each study session, you are not given such luxury in an academic environment; most classes span 3-4 months in length and have between two to four big tests during that time, along with weekly quizzes and homework. Thus, the best thing to do with a test for school is to use the 24 hour spacing interval to restudy your material. Within the first several days of learning, you should space out your learning between every 24 hours. After the first four review sessions (with 24 hours between each review), your review sessions can be further spaced out and less detailed. In fact, letting a month go by after the first four review sessions is completely fine.
Combine distributed practice and practice testing and your test scores should skyrocket. For the overwhelming majority of your academic endeavors, distributed practice combined with practice testing is enough to ace your exams and learn the material.
Moderate Efficiency Study Methods
Elaborate interrogation, self-explanation, and interleaved practice received moderate utility assessments. They are rated as moderate because more research needs to be done in the efficacy of the methods, the efficacy was variable across tasks and topics, and/or some in-depth training was required. But the general consensus from the various research studied in the meta-analysis show that it works.
Elaborative Interrogation (Moderate)
Elaborative interrogation is the process of asking yourself why in an attempt to understand concepts. For instance, if you are learning about E=MC^2, a starting question you might ask yourself is “why does E equal MC^2?”. This method is extremely simple to use and require no training; however it does require some familiarity with the topic (and related topics) to be effective.
This method is particularly efficient with time as one study on self-paced learning showed that elaborative interrogation took 32 minutes (reading + elaborative interrogation) compared to 28 minutes for the reading-only group. This is particularly good news as reading is generally monotonous thus elaborative interrogation done during reading can enhance learning by taking away the monotony.
However, the thing is that elaborative interrogation is rather limited in its application; its application is limited to answering factual statements, such as the E=MC^2 statement above. When learning about a complex chain of relationships, such as digestive system.
Tips for elaborative interrogation: Elaborative interrogation can be very effective when done frequently. So as you are reading, be sure to check your understanding of the material by asking yourself questions every couple of paragraphs or so. Research suggests that the gains from this technique are diluted when elaborative interrogation is employed once every 1-2 pages. To make further use of this technique, use a notebook to write down the questions you are asking as well as the answers as you are reading along. This practice of writing down your questions/answers further commits the material to memory.
Self-explanation is a close relative of elaborative interrogation. This method involves the participant explaining and recording how one reaches an answer or conclusion. This is actually a popular method for solving abstract problems and similar to the requirement in many math classes to show your work. This was found to be more effective when done during the initial learning stage, instead of after learning. A strength of this learning strategy is that it can be applied to a whole variety of tasks and subjects. However, studies show that this method does require some training and is one of the more time consuming methods of study. Additionally, there have not been too many studies that have tested long-term retention of the material learned through self-explanation; most studies administered testing minutes after the conclusion of the tasks.
Tips for self-explanation: When doing self-explanation, it helps to write out the questions that you want to ask yourself and then write down the answers. The process of writing the questions and answers down further commits the concepts to memory, and lets your brain organize the importance of the materials.
Interleaved practice (Moderate)
Interleaved practice is when the student studies the topic at hand but also blends the study with previous topics/concepts at the same time. For instance, if a student is learning the concept of polynomials this week in Algebra but learned about simplifying algebraic equations, and solving inequalities the previous couple of weeks, then interleaved practice means that the student should spend most of his time studying polynomials but also spend a fair amount of time simplifying algebraic equations and solving inequalities.
This method was talked about extensively in Barbara Oakley’s book A Mind for Numbers. She is a heavy proponent of interleaved practice and its cousin, spaced repetition. The studies show that this method has tremendous potential to improve learning and retention of science and mathematics in students. Additionally, interleaved practice helps in many other cognitive skills.
On the not-so-positive side, although studies on this method are sparse, a few of them show that the method may not work in some scenarios. However, this may be because of implementation, a lack of training, or because interleaved practice does not work across a broad range of subjects. The authors of the study acknowledged that there seems to be a lot of potential in this method, but there needs to be more research done before it is regarded as a high utility method.
Tips for interleaved practice: Interleaved practice is a must if you are doing math and science. The practice of going back through previous chapters and topics act as a much-needed refresher because much of math and science builds on previously studied material. Interleaved practice also shows great promise for learning foreign languages also. Thus what you should do is mix in work from previous topics/chapters in with your current work when you are studying. This process of interleaving also solidifies your knowledge base as you gain a greater understanding of when to use certain methods and when not to.
Low Efficiency Study Methods
Summarization, highlighting/underlining/marking, mnemonics, imagery use for text learning, and rereading all received low efficiency grade in the meta-study. The reason for their low utility grade differs; the studies into the methods show mixed results, it is not generalized, has narrow applications, and/or its efficiency is limited.
Highlighting, underlining, and marking materials (low)
Highlighting is one of the most popular methods for students in college. Although an extremely popular method of learning, highlighting ranked rather low on this study’s utility scale. This technique is popular because it is very easy to implement and require very little training. Most studies analyzed in the meta-analysis showed no noticeable improvement in test scores by highlighting over simply reading the information. Although highlighting, underlining, and marking materials is often paired with other methodologies of learning, the study evaluated highlighting on its own merit. Thus the reason that highlighting does score a higher utility score on this meta-analysis is because its effectiveness and applicability is limited to certain information and tasks.
Tips for highlighting: Although highlighting alone has shown to be no more effective than simply reading the material, the combination of highlighting with other methods in the study will prove to be effective in retaining information for testing. For instance, employing the use of highlighting with recall/self-testing can prove to be effective in internalizing the material.
Summarization is pretty self-explanatory; it is the process of summarizing a section of chapter you are trying to learn. In theory this method should work because it involves extracting the gist and higher-level meaning of learned text, which is important to understanding concepts.
Results from multiple studies seem to indicate that summarization helps with performance on generative measures (e.g. free recall or essays) but do not help when it comes to multiple-choice questions or other questions that do not require the student to produce information. Thus, summarization is better suited for tests that involved in the production of information rather than tests that rely on recognition of concepts.
Although some studies have shown promise in summarization, others failed to find benefit. Consider the study in 1986 by Wong, Wong, Perry, & Sawatsky. The study found that those who were tasked to summarize textbook passages about earthquakes performed no better (overall) than the control group when tested a week after. The study concluded that students benefited from the technique when the questions required the application or analysis of knowledge, but summarization led to decreased performance when the questions required evaluation or analysis of knowledge.
Summarizing was found to be effective for those already adept at summarizing. The quality of the summary matters. Summaries that included more information and were linked to prior knowledge were shown to do better.
Summarization is ranked low in this meta-analysis because the effectiveness of summarizing was not general; the nature of the material and the test matters quite a bit when it comes to how effective summarization is. The quality of the summary had a huge effect on the effectiveness of the summarization, from no effect to highly effective. Summarizing was found to be more beneficial than rereading, highlighting, and underlining.
Tips for summarization: If you are summarizing, it is important to get the core concepts and the overall concepts correct as it is the basis of your knowledge. Additionally, summarize using shorthand notations that you develop as it will allow you to summarize more of the material. Also, combine summarization with practice testing will allow you to really get down the material, without having a false sense of competence.
Rereading is another popular technique used by students. Rereading has always been one of my least favorite methods of study just because I feel like I don’t get much out of it for the time I put into rereading. Turns out, there is a scientific basis for my loathe of rereading.
Theoretically, rereading improves learning because it increases the total amount of information encoded, regardless of the kind or level of information contained within the text. However, when rereading was compared to other methods of learning, rereading did not fare well. Although rereading requires no training, the amount of time spent reading does not give a favorable return on investment. The meta-study showed that there is in fact a diminishing return on investment after the first rereading as students gain very little after the first rereading.
Tips for rereading: If you are going to reread, doing so by leaving a little bit of time (but not too much) between the initial reading and the rereading. In a study by Verkoeijen, Rikers, and Ozsoy in 2008, learners did best when they let 4 days pass between the initial rereading and the rereading. In between those 4 days, you can move on with the next topic, and reread after 4 days. So with this method, you are reading new material as well as rereading old material every day.
This ranked surprisingly low in the meta-study but I imagine the reason it is low is because it does require some training and can only be applied to specific types of tests/tasks that require memorization. For instance, it may not help as much when you are attempting to use this method to solving a linear algebra problem. The idea of a mnemonic device is to develop mental images and associations with a word or term. The study’s authors acknowledge that there is a tremendous amount of evidence that shows mental imagery is a powerful form of learning, positing that mental imagery is great for things such as 1) learning new foreign vocabulary 2) medical terminology 3) definition of words 4) minerals and their attributes 5) scientific definitions. However, the authors found that the method was lacking when it came less concrete ideas/words. The limited applicability of the method is the main reason for its low utility.
Tips for mnemonics: Don’t let the low utility grade fool you, keyword mnemonics is a very valuable learning tool for memorizing many ideas/words. In order to create more durable knowledge, the mental imagery needs to be more memorable, and needs to be revisited a few times in spaced intervals. It may also be a good idea to use a memory palace to store your imagery. For more information about using memory palaces, check out Josh Foer’s fascinating book Moonwalking With Einstein.
Imagery Use for Text Learning
This method is different from keyword mnemonics as this method forms a mental image of a whole sentence/concept, instead of a single keyword. The authors stated that:
Developing images can enhance mental organization or integration of information in the text, and idiosyncratic images of particular referents in the text could enhance learning as well (cf. distinctive processing; Hunt, 2006). Moreover, using one’s prior knowledge to generate a coherent representation of a narrative may enhance general understanding of the text; if so, the influence of imagery use may be robust across criterion tasks that tap memory and comprehension.
However, the research suggests that the method is rather limited in nature. This method, like the keyword mnemonics method above, does require some training to do effectively. Studies of imagery use has only been limited to text that are rather easy to imagine, and not abstract concepts, such as topics that are more mathematical and scientific in nature. But even studies with image-friendly reading shows that the results are a mixed bag. Some studies show students benefited, while others did not.
Though there is evidence of benefit when imagery is used for just one sentence, a study of this method using long text found that imagery use in text learning had no noticeable benefit on high school students.
Overall imagery use for text learning receives a low utility score because of its variability in result, and the fact that it only works for short image-friendly text. Additionally, a large amount of training is required to use the method.
Imagery of text material tips: To make the most of imagery, make sure that the images are extremely memorable. It can help to draw out the concept on paper and then visually taking a picture with your head.
Ranking from Best to Worst
Although the meta-study did not specifically provide a 1-10 ranking in terms most effective to least effective study methods, I will attempt to extrapolate the rankings from my analysis of the study. Here is the ranking of the most effective study method to the least effective:
Ranking (best to least)
- Distributed practice
- Practice testing/self-testing
- Interleaved practice
- Elaborative interrogation
- Keyword mnemonics
- Imagery of text
Remember, these ten study methods were analyzed on its own merit, not when they are combined with other methods. To have an effective strategy for studying, it is best to combine several methods together.