I spent all of yesterday (and continue today and tomorrow) at the Web2.0 Conference in San Francisco. Obviously, there are many covering the event (Om Malik lists his ten “exciting side notes” and Jeff Jarvis reviews his thoughts from the companies profiled at the Launch session). I’ll post something later this week with my higher-level thoughts from the event, but the following are just a few tidbit reactions to some of the sessions yesterday.

Tagging is a short word, but requires a long explanation. Jeff Jarvis crystallized it right during the session on tags when he said, “I want a tutorial in the art of tagging.” The crowd – which was a sophisticated one – agreed. Others echoed wondering if they were “doing it right.” While I believe that there is immense power in the collective input towards categorizing and labeling media units, there is definitely a significant barrier transitioning usage from the digerati to the average consumer. How do I explain when someone with moderate internet savvy asks me, “What is tagging? Why and how should I do it?” Yes, there’s a compelling answer that I can give, yet it’s not a short one. But I do think that we are still in the exploratory phase and that the response will become more concise and clear over time.

Difficulty of collective action. I heard presentations from many companies and organizations that are pursuing and pushing initiatives that would arguably positively affect the industry as a whole – attention data management, structured blogging, central identity management – but they face a significant challenge of adoption. Unlike the potential incremental embracement of consumers which can ramp over time, these appear to me to require collective action on both consumer and organization fronts. While many of these are noble pursuits, I am skeptical about the ability of these to solve the chicken and egg adoption problem facing them. What am I missing here?

Measuring abstract concepts. Caterina Fake talked about the “interestingness” of specific photos on Flickr: a measurement somewhere between relevance and popularity. People in the advertising models session talked about “engagement”: the measurement of how deep the relationship a viewer has with an online advertisement. Both of these notions go beyond are the basic dimensions originally associated with these objects. Striving towards them may seem like a reach now, but it’s a good reminder to think that relevance and tracking pay-per-performance were originally challenges during the Web 1.0 time-period.