The quality of open educational resources (OER) has been a continuous topic of interest over the past two decades, because it is intertwined with the adoption of these resources. In previous research the quality of OER has been defined on the basis of quantitative or usage data, but few qualitative insights are available. In this study we analysed how teachers collaboratively assessed ‘big’ OERs, and whether changes occurred in teachers' perceptions of OER by means of collaborative dialogue about the quality of these resources. Five core themes were elicited: (1) content, (2) design, (3) usability, (4) engagement, and (5) readability. Changes we discerned in teachers' perceptions relate to their awareness, attitude and practical issues in relation to OER. Higher education institutes aiming to increase the use of OER should encourage conversation on OER in teacher teams during curriculum reforms, and provide support for the adaptation of resources to teachers' instructional needs and their specific teaching contexts.

在过去的二十年里，开放教育资源 (OER) 的质量一直是人们感兴趣的话题，因为它与这些资源的采用息息相关。在以前的研究中，OER 的质量是根据定量或使用数据来定义的，但很少有定性的见解可用。在这项研究中，我们分析了教师如何协作评估“大”开放式教育资源，以及通过关于这些资源质量的协作对话，教师对开放式教育资源的看法是否发生了变化。引出了五个核心主题：(1) 内容，(2) 设计，(3) 可用性，(4) 参与度，和 (5) 可读性。我们发现教师观念的变化与他们对开放教育资源的认识、态度和实际问题有关。