Introduction
Understanding and applying are the most common goals of learning. In the e-learning environments; the only way to ensure that goals are achieved is through feedback. Despite this, there is no comprehensive framework based on the science of education, so that how to create educational feedback based on learning objectives.
Method
The purpose of this study was to compilation the educational standards and their indicators for design effective feedback for the first three layers (remembering, understanding and applying) of the Bloom-Anderson’s taxonomy. The qualitative research approach is used and based on this approach, the phenomenological design strategy has been used. The population included 12 people of subject matter and faculty members in academic e-learning centers which were selected through purposeful sampling. Qualitative data generated from interviews were coded and analyzed by Corbin and Strauss method and Maxquda software. To ensure the consistency of the coding in the qualitative section, inter-coder reliability analysis was performed. To this end, initially, the transcribed data of the interview files (3 random interviews) was scrutinized by a fellow researcher with expertise and experience in research and emerging characteristics noted. Next, through matching the fellow researcher’s noted concepts with those observed by the author(s) of the present study, the percentages of the inter-coding agreement and discrepancy of the extracted concepts were reviewed and modified accordingly.

Results
The results of the study led to the development of 4 educational standards and 21indicators based on Bloom-Anderson’s taxonomy to design comprehensive feedback in the field of e-learning. According to the results of this study, educational technologists and assessors can evaluate or design more effective E-learning environments. Developing standards and indicators for feedback methods in e-learning environments can provide a practical guide for instructors and explain the minimum requirements for implementing effective teaching. To ensure the comprehensiveness of these indicators and the ability to cover different learning objectives, these indicators were compared with the Bloom-Anderson taxonomy.

Discussion
According to the analysis of interviews; Feedback based on action, Multichannel feedback, Feedback based on the future and Feedback based on obstacles of learning are the indicators for achievement situational learning. Also, Assist leveling feedback, feedback fits user level understanding, Transitional feedback and feedback with dual and delayed are the indicators for feedback based on scaffolding. Finally, it should be said that despite limitations such as the limited number of educators with experience in and expertise on e-learning, the limited number of universities that provide formal education through a learning management system, and the constraints in communication with overseas experts on e-learning, the results of the present study succeeded in developing important indicators of feedback methods in virtual learning environments (VLEs) based on the Bloom-Anderson taxonomy.