Instructors may have difficulty in assessing student participation in the weblog. There are several indicators to take into account: group grading, individual posting, quality of posts, etc., as well as subjectivity vs. qualitative appreciations.
• The use of technology- based tools may be another barrier. It can be of a structural nature, for instance lack of computers, or difficult access to the Internet (as happens in Spain where the Internet connection is quite expensive and slow). Another source of disadvantage would be computer illiterate users, specially in those countries with a wide digital divide.
• Even though most weblogs are hosted in public, free ASPs, learning weblogs should be hosted in private servers, so that they do not show neither advertisements nor banners (which are the most common method of ASPs financing).
• System administrators tend to be restrictive in installing new software.
• If the weblog is public, it may suffer troll infestations, people that intentionally try to cause disruption by posting messages that are inflammatory, insulting, incorrect, inaccurate, or offtopic, with the intent of provoking a reaction from others.