Oak’s Aila saves primary teachers 49 minutes a week on lesson planning, EEF trial finds

Teachers using the AI lesson assistant spent about 2.5 hours a week preparing lessons compared with 3.3 hours in the comparison group, with no evidence that the quality of their resources was worse

A new EEF-commissioned trial found that teachers assigned to use Oak National Academy’s Aila AI lesson assistant spent around 49 minutes less per week on lesson and resource preparation

Oak National Academy’s AI lesson assistant Aila saved primary teachers an average of around 49 minutes a week on lesson and resource preparation without reducing the quality of the materials they produced, according to a new independent randomized controlled trial.

The Education Endowment Foundation (EEF) commissioned the evaluation, which was carried out by the National Foundation for Educational Research (NFER). It tested Aila with Year 3 to Year 6 teachers in England over ten weeks during autumn 2025.

Teachers using Aila spent 76% as much time preparing lessons and resources as teachers in the comparison group, averaging around 2.5 hours a week against 3.3 hours.

Independent assessment of the lesson resources found that materials produced by the Aila group were no worse in quality than those from teachers who had not been assigned to use the tool.

The EEF gives the evaluation a high security rating, reflecting what it describes as a rigorous design, strong delivery and confidence in the time-saving finding.

Teachers used Aila for only a small proportion of lessons

The size of the time saving sits alongside a more complicated picture of how teachers actually used the technology.

Although 81% of teachers in the Aila group used it at least once, Aila was used for only around 7% of lessons in an average week, and use declined during the ten-week trial.

Teachers who used the platform more frequently tended to save more time. The pattern remained when researchers excluded the first week of the trial and the half-term break.

The evaluation suggests one reason for relatively low use was the way Aila had originally been designed. Its core function supports teachers planning lessons from scratch, while teachers often already had existing materials that they wanted to adapt instead.

Teachers could also continue using other generative AI tools, including ChatGPT and Microsoft Copilot, during the trial.

John Roberts, co-founder and CEO of Oak National Academy, wrote on LinkedIn that teacher behavior during the study had influenced how Oak is developing the product: “Over the term, many chose to adapt existing materials rather than ask Aila for whole lessons from scratch.”

He added that Oak is now bringing Aila’s capabilities more directly into its existing lessons and resources.

Early-career teachers saw the strongest benefits

The time-saving benefits were greatest among teachers newer to the profession, those with lower confidence in their subject or pedagogical knowledge, and teachers with greater confidence using technology.

Teachers’ overall views were mixed. Some found Aila accessible, valued its curriculum alignment and found it particularly useful when planning unfamiliar topics.

Others preferred different AI tools, while fewer than one in five teachers said Aila had meaningfully changed their teaching or planning. Teachers commonly used it alongside their existing processes and adapted its outputs before using them in the classroom.

The EEF cautions that saving planning time does not automatically mean better teaching. Teachers still need to check and adapt AI-generated materials for accuracy, sequencing, suitability for their students and the wider curriculum.

The findings point towards targeted use rather than wholesale automation of lesson planning, particularly where teachers need to adapt materials, create resources or work in less familiar curriculum areas.

Independent evidence falls below Oak’s earlier estimates

Aila launched in beta in 2024 as an education-specific generative AI tool built around Oak National Academy curriculum resources and designed to involve teachers throughout the lesson-planning process.

Roberts said the independent result was lower than estimates generated through Oak’s own earlier surveys, and used the gap to argue for more independent evaluation of AI in schools.

“Our own early surveys suggested bigger savings than this trial found. That gap is exactly why independent evaluation matters. Testimonials are not enough,” he wrote on LinkedIn.

He also cautioned that the evidence inevitably trails the technology itself because data for the trial was collected in late 2025.

The evaluation found almost all participating teachers regarded lesson planning as a source of stress and felt they spent too much time on it. Aila remains free to use online, with teachers able to access the tool by creating an Oak National Academy account.