1.教师临场感：Teaching  presence  can  be  argued  as  necessary  for  bridging  the transactional distance between  learner and  instructor in online courses (Arbaugh  &  Hwang,  2006).

即：教师临场感可以被认为是连接学习者与教师的桥梁

1.1教师临场感包括三个维度：Garrison et  al.  (2000)  conceptualize teachingpresence  as  comprised  of  three  underlying  dimensions:  (a)  instruc- tional  design  and  organization,  (b)  facilitating discourse,  and  (c)  di- rect  instruction.

  即：教师临场感包含三个维度
1.教学设计和组织
2.促进交流
3.指导教学

具体的指：  (a)  organized  and  designed  courses  to  communicate  information about  course  topics,  course  outcomes,  course  learning  activities,  as- signment due  dates,  and  instructions for using  the medium;  (b)  facili- tated discussions  that acknowledged  student participation, encouraged exploration of new  concepts,  and  sought  consensus;  and  (c)  used  di- rect  instructional  activities  to  focus  learners  on  relevant  issues,  pro- vide direct feedback, correct misconceptions, and to  relate knowledge from  a  variety  of  sources.

   1.2教师临场感的作用：

Assessing perceptions of teaching presence occurring within online courses  and  making  revisions  based  on  this  feedback  is  important, because  research  clearly  demonstrates  that  the  quality  of  instructor interactions  is  a  significant  determinant  of  student  satisfaction,  per- ceived  learning,  and  sense  of  community  (e.g.,  Garrison  &  Cleve-
land-Innes,  2005;  Shea,  2006;  Shea,  Pickett,  &  Pelz,  2004).

2.认知临场感

定义：

Garrison,  Anderson,  and  Archer  (2001)  describe  cognitive  pres- ence as  the  extent  to which  learners  are  able  to construct and confirm meaning  through  sustained  reflection and  discourse within communi- ties of inquiry supported by CMC.

包括四个方面：

The  phases  of cog- nitive  presence  defined  by  Garrison  et  al.  (2000)  are  represented  by the  following  four  dimensions:
1.  Triggering  Event（触发性事件） -  An  issue or dilemma  under consideration emerges.  This  phase might   be  instructor  initiated  or  emerge from  a  previous  discussion  exchange.
2.  Exploration （探索） -  Experiences  from  one's  private  and  shared worlds are considered relative  to  the  issue.  This  phase  is defined  by  discussions  that  include brainstorming,  question-ing,  and  exchanging  of  information.
3.  Integration（重组）  -  Meaning  is  constructed  from  ideas  generated in  the  exploratory  stage.  Discourse  involves  identifying  a range  of possible  solutions  and discussion  of their suitability for  solving  the  identified  problem  or  issue.
4.  Resolution（方法）  -  Discussions  focused  on  consensus  building. Reasoned  solutions  selected  from  the  Integration  Phase  are selected  and defended. The  validity of solutions  is often tested by  discussing  applications  to  learners'  real-life  experiences.

从简单到复杂，逐逐步递进的认知过程。 

 摘自：The Influence  of Social Presence and Teaching Presence on the Quality of Online Critical Inquiry （Journal  of Computing  in Higher Education Fall 2008, Vol. 20(1), 34-61. ）