Context:
Many articles have been published about emergency remote teaching (ERT) during the Covid-19 pandemic. For successful ERT, teachers’ readiness was a key factor as most teachers during their studies were not prepared to teach in remote conditions without face-to-face contact with their students.
Learning curve is a way to visually represent the fact of learning. The learning curve is a graphical “curve plotting performance against practice; the course of progress made in learning something” (Merriam-Webster, n.d.). It reflects individual progress in time units against the invested resources.

Purpose or goal:
This study investigated teachers’ readiness for ERT during one year of the pandemic (from May 2020 to May 2021). The aim was to analyze how teachers acquire new skills and how the knowledge is shared during the ERT. We intended to develop a learning curve model for crisis situations.

Approach:
Based on previous research on the available readiness for online learning, a self-evaluation survey to measure teachers’ “Readiness for Emergency Remote Teaching” was developed. It consisted of 47 five-point Likert-scale items and demographic questions.
All answers were analyzed by the subject areas, and learning curves were developed for each subject area to compare teachers’ professional development towards readiness for ERT in 2020 and 2021.

Actual or anticipated outcomes :
Readiness for ERT was calculated and analyzed based on the subject area. Statistically significant differences between the answers in 2020 and 2021 were found. Readiness for ERT after the second school year had become higher in all subject areas (p < 0.05) except native language and Computer science.
After analyzing various learning curve models, we chose Towill’s Constant time model as it is suited for cases when individual has had some practice. Three different models were developed in the study:
(1) learning curve without previous experience;
(2) learning curve with accumulated experience;
(3) learning curve with knowledge sharing. Based on the original equation of Constant time model we developed several equations and calculated the time when the readiness for ERT could have emerged.

Conclusions/Recommendations/Summary:
Learning curve model with knowledge sharing confirmed that the starting point of ERT skills acquisition was different in each subject area (except Computer Sc.), but during the year the skills in all subject areas had been aligned. It proves that during crisis teachers’ learning included an important factor for success – knowledge sharing and cooperation within teacher communities.

Keywords: Learning curve, Covid-19, emergency remote teaching, K-12, knowledge sharing, readiness for remote teaching.