In many English classes, the teacher explains grammar and students do drills. In task-based classes, students use English to do something, like planning a trip. A 2019 study looked at 52 studies and said task-based classes worked very well.

Later, other researchers checked the numbers again. The effect was smaller than before, and some studies were hard to compare. Today, some experts think good lessons use tasks and also give some grammar help.

Task-based language teaching, or TBLT, asks students to use English to complete real tasks, such as solving a problem in a group, instead of mainly practicing grammar rules. In 2019, a meta-analysis of 52 studies reported a strong positive effect for TBLT programs. However, the story did not end there. In 2021, a paper that included the original authors warned that the results should be read carefully, because many comparison studies did not really fit the purpose.

Another team then repeated the analysis with stricter rules and found a smaller effect, dropping from 0.93 to 0.61. An experiment with 150 Chinese middle school students also suggested that tasks worked better when combined with grammar explanations and feedback. So the question is how to mix tasks and grammar.

Task-based language teaching (TBLT) organizes lessons around meaningful tasks, such as planning a trip or solving a problem, rather than around a sequence of grammar presentations and drills. Its supporters received a major boost in 2019, when a meta-analysis of 52 studies reported a strong overall effect for TBLT programs, with an effect size of 0.93. What happened next, however, shows why research has to be read with care. In 2021, a group of scholars that included the two authors of that meta-analysis argued that its conclusions should be interpreted cautiously.

Re-examining the 27 studies that had compared TBLT with other programs, they judged that all but one were poorly suited to answering the question. A separate team then applied stricter inclusion criteria and obtained a more modest effect of 0.61, noting that only sample size and whether the teacher was also the researcher explained differences between studies. By 2023, two of the critics concluded that the field was simply not ready for a meaningful meta-analysis of this question. Meanwhile, a controlled experiment suggests that tasks combined with explicit instruction and feedback may be more effective than tasks alone.